SYM 1.

GENERAL INFORMATION/TROUBLE DIAGNOSIS

SYMBOLS AND MARKS .................... 1-1 TORQUE VALUES (ENGINE) .............. 1-10
GENERAL SAFETY............................ 1-2 TORQUE VALUES (FRAME) ............... 1-11
SERVICE PRECAUTIONS ................. 1-3 TROUBLES DIAGNOSIS ..................... 1-12
SPECIFICATIONS .............................. 1-9 LUBRICATION POINTS ....................... 1-16

SYMBOLS AND MARKS

Symbols and marks are used in this manual to indicate what and where the special service are
needed, in case supplemental information is procedures needed for these symbols and marks,
explanations will be added to the text instead of using the symbols or marks.

Means that serious injury or even death may result if procedures are not
Warning followed.

Caution Means that equipment damages may result if procedures are not followed.

Limits to use SAE 10W-30 API SH/CD class oil. Warranty will not cover the
Engine oil damage that caused by not apply with the limited engine oil.

Limits to use SAE 85W-140 class oil. Warranty will not cover the damage
Gear oil that caused by not apply with the limited gear oil.

Grease King Mate G-3 is recommended.

Apply sealant, medium strength sealant should be used unless otherwise

specified.
Locking sealant

Oil seal Apply with lubricant.

Renew Replace with a new part before installation.

Brake fluid Use recommended brake fluid DOT3 or WELLRUN brake fluid.

Special service tools.

Special tools

Correct Meaning correct installation.

Wrong Meaning wrong installation.

Indication Indication of components.

Directions Indicates position and operation directions.

Components assembly directions each other.

Indicates where the bolt installation direction, --- means that bolt cross
through the component (invisibility).

1-1
1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM
GENERAL SAFETY
Carbon monoxide Battery
If you must run your engine, ensure the place is Caution
well ventilated. Never run your engine in a
closed area. Run your engine in an open area, if  Battery emits explosive gases; flame is
you have to run your engine in a closed area, be strictly prohibited. Keep the place well
sure to use an extractor. ventilated when charging the battery.
 Battery contains sulfuric acid (electrolyte)
Caution
which can cause serious burns so be careful
Exhaust contains toxic gas which may cause
do not be spray on your eyes or skin. If you
one to lose consciousness and even result in
get battery acid on your skin, flush it off
death.
immediately with water. If you get battery
acid in your eyes, flush it off immediately
with water, then go to hospital to see an
Gasoline
ophthalmologist.
Gasoline is a low ignition point and explosive  If you swallow it by mistake, drink a lot of
material. Work in a well-ventilated place, no water or milk, and take some laxative such
flame or spark should be allowed in the work as castor oil or vegetable oil, and then go to
place or where gasoline is being stored. see a doctor.
Caution  Keep electrolyte beyond reach of children.
Gasoline is highly flammable, and may explode
under some conditions, keep it away from
children.

Brake shoe
Used engine oil Do not use an compressed air or a dry brush to
clean components of the brake system, use a
Caution
vacuum cleaner or the equivalent to avoid
Prolonged contact with used engine oil (or asbestos dust flying.
transmission oil) may cause skin cancer
Caution
although it might not be verdict.
Inhaling asbestos dust may cause disorders
and cancer of the breathing system.

Hot components
Caution
Components of the engine and exhaust Brake fluid
system can become extremely hot after
Caution
engine running. They remain very hot even
after the engine has been stopped for some Spilling brake fluid on painted, plastic, or rubber
time. When performing service work on parts may cause damage to the parts. Place a
clean towel on the above-mentioned parts for
these parts, wear insulated gloves and wait
protection when servicing the brake system.
until cooling off.
Keep brake fluid beyond reach of children.

1-2
SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS
SERVICE PRECAUTIONS
 Always use with SANYANG genuine parts  Never bend or twist a control cable to prevent
and recommended oils. Using non-designed stiff control and premature worn out.
parts for SANYANG motorcycle may damage
the motorcycle.

 Rubber parts may become deteriorated when

 Special tools are designed for remove and old, and prone to be damaged by solvent and
install of components without damaging the oil. Check these parts before installation to
parts being worked on. Using wrong tools make sure that they are in good condition,
may result in parts damaged. replace if necessary.
 When loosening a component which has
different sized fasteners, operate with a
diagonal pattern and work from inside out.
Loosen the small fasteners first. If the bigger
ones are loosen first, small fasteners may
receive too much stress.
 Store complex components such as
transmission parts in the proper assemble
order and tie them together with a wire for
ease of installation later.
 When servicing this motorcycle, use only
metric tools. Metric bolts, nuts, and screws
are not interchangeable with the English
system, using wrong tools and fasteners may
damage this vehicle.
 Clean the outside of the parts or the cover
before removing it from the motorcycle.
Otherwise, dirt and deposit accumulated on
the part's surface may fall into the engine,
chassis, or brake system to cause a damage.
 Wash and clean parts with high ignition point
solvent, and blow dry with compressed air.
 Note the reassemble position of the important
Pay special attention to O-rings or oil seals
components before disassembling them to
because most cleaning agents have an
ensure they will be reassembled in correct
adverse effect on them.
dimensions (depth, distance or position).
 Components not to be reused should be
replaced when disassembled including
gaskets metal seal rings, O-rings, oil seals,
snap rings, and split pins.

1-3
1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM
 The length of bolts and screws for  Remove residues of the old gasket or sealant
assemblies, cover plates or boxes is different before reinstallation, grind with a grindstone if
from one another, be sure they are correctly the contact surface has any damage.
installed. In case of confusion, Insert the bolt
into the hole to compare its length with other
bolts, if its length out side the hole is the
same with other bolts, it is a correct bolt.
Bolts for the same assembly should have the
same length.

 The ends of rubber hoses (for fuel, vacuum,

or coolant) should be pushed as far as they
can go to their connections so that there is
enough room below the enlarged ends for
tightening the clamps.

Groove

 Tighten assemblies with different dimension

fasteners as follows: Clamp
 Tighten all the fasteners with fingers, then
tighten the big ones with special tool first Connector
diagonally from inside toward outside,
important components should be tightened 2
to 3 times with appropriate increments to
avoid warp unless otherwise indicated. Bolts  Rubber and plastic boots should be properly
and fasteners should be kept clean and dry. reinstalled to the original correct positions as
Do not apply oil to the threads. designed.

Boots
 The tool should be pressed against two
(inner and outer) bearing races when
 When oil seal is installed, fill the groove with removing a ball bearing. Damage may result
grease, install the oil seal with the name of if the tool is pressed against only one race
the manufacturer facing outside, check the (either inner race or outer race). In this case,
shaft on which the oil seal is to be installed the bearing should be replaced. To avoid
for smoothness and for burrs that may damaging the bearing, use equal force on
damage the oil seal. both races.

Manufacturer's name

Both of these examples can result in bearing

damage.

1-4
SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS
 Lubricate the rotation face with specified  Before battery removal operation, it has to
lubricant on the lubrication points before remove the battery negative (-) cable firstly.
assembling. Notre tools like open-end wrench do not
contact with body to prevent from circuit short
and create spark.

 Check if positions and operation for installed

parts is in correct and properly.

 After service completed, make sure all

connection points is secured. Battery
positive (+) cable should be connected firstly.
And the two posts of battery have to be
greased after connected the cables.
\

 Make sure service safety each other when

conducting by two persons.

 Make sure that the battery post caps are

located in properly after the battery posts had
been serviced.

 Note that do not let parts fall down  If fuse burned, it has to find out the cause
and solved it. And then replace with
specified capacity fuse.

capacity
verification

1-5
1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM
 When separating a connector, it locker has to  Before terminal connection, check if the boot
be unlocked firstly. Then, conduct the is crack or the terminal is loose.
service operation.

 Insert the terminal completely. Check if the

terminal is covered by the boot. Do not let
boot open facing up.

 Do not pull the wires as removing a

connector or wires. Hold the connector
body.

 Secure wires and wire harnesses to the

frame with respective wire bands at the
designated locations. Tighten the bands so
that only the insulated surfaces contact the
 Make sure if the connector pins are bent, wires or wire harnesses.
extruded or loosen.

 Insert the connector completely. If there are  Wire band and wire harness have to be
two lockers on two connector sides, make clamped secured properly.
sure the lockers are locked in properly.
Check if any wire loose.

 Check if the connector is covered by the twin  Do not squeeze wires against the weld or its
connector boot completely and secured clamp.
properly.

1-6
SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS
 Do not let the wire harness contact with  Protect wires or wire harnesses with electrical
rotating, moving or vibrating components as tape or tube if they contact a sharp edge or
routing the harness. corner. Thoroughly clean the surface where
tape is to be applied.

 Keep wire harnesses far away from the hot

parts.  Secure the rubber boot firmly as applying it
on wire harness.

Do not touch it.

 Never use wires or harnesses which

 Route wire harness to avoid sharp edges or insulation has been broken. Wrap electrical
corners and also avoid the projected ends of tape around the damaged parts or replace
bolts and screws. them.

 Route harnesses so that they neither pull too

tight nor have excessive slack.
 Never clamp or squeeze the wire harness as
installing other components.

Please do not clip or

squeeze the wire.

Do not extend
it too much.

1-7
1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM
 Do not let the wire harness been twisted as  With sand paper to clean rust on connector
installation. pins/terminals if found. And then conduct
connection operation later.

Clean rust.

 Wire harnesses routed along the handlebar

should not be pulled too tight or have
excessive slack, be rubbed against or
interfere with adjacent or surrounding parts in
all steering positions.

 Before operating a test instrument, operator

should read the operation manual of the
instrument. And then, conduct test in
accordance with the instruction.

Do you know how to set the

instrument to its measurement
position and the insert locations
of its two probes?

1-8
SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS
SPECIFICATIONS
MAKER SANYANG MODEL XC20W2-EU

Suspen
Overall Length 1990±20mm Front TELESCOPIC FORK

System
sion
DIMENSION

Overall Width 730±10mm Rear DOUBLE SWING ARM

Overall Height 1115±20mm Front 100/90-14

cations
Specifi
Tire
Wheel Base 1350±20mm Rear 110/80-14

Front 53±2 kg
Curb Weight

Front DISK (ø 260 mm)

System
Brake
Rear 81±3 kg

Total 134±6kg Rear DISK (ø 220 mm)

WEIGHT

Passengers/
Performa
Two men/184 kg Max. Speed 95 km/hr Above
Weight
nce
Front 89±3kg Climb Ability 32.5 %% slope
Total Weight

Rear 195±3 kg Primary Reduction C.V.T.

Deceleration
equipment

Secondary
Total 284±6kg belt, 2.604~ 0.717
Reduction
Type 4-STROKE ENGINE Clutch Centrifugal, dry type
Installation and Vertical, below center,
Transmission V-belt
arrangement incline 80°
Fuel Used unlead gasoline Speedometer 0 ~ 140 km/hr
4-stroke/forced air
Cycle/Cooling Horn 87~112 dB/A
cooled
Bore 61 mm Muffler Expansion & Pulse Type
Cylinder

Exhaust Pipe Position Right side, and

Stroke 57.8 mm
and Direction Backward
Number/Arra forced circulation &
ENGINE

Single Cylinder Lubrication System

ngement splashing
Displacement 169cc Exhaust CO% ＜1.14 g/km
Emission
Compression
10.3±0.2 : 1 (IDLE) HC% ＜0.38 g/km
Ratio
Idle speed 1800±100 rpm Fuel tank capacity 7.5L

Max. HP 9KW / 7500 rpm Air Filtration Paper filter

Max. Torque 12.5N.m /6000 rpm Noise Emission < 74dB

25A*1&15A×2
ECU M4B Fuse
&20A×1&10A×1
Starting System Electrical starter

1-9
1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM
TORQUE VALUES (ENGINE)
THREAD DIA TORQUE
ITEM Q'TY REMARKS
(mm) VALUE(Kg-m)
A.C. generator flange bolts 2 6 0.8~1.2
L side cover plate pan screws 7 5 0.5~0.7
Engine oil filter screen cover 1 30 1.0~2.0
Crankcase bolts 2 6 0.8~1.2
Oil pump flat screws 2 6 0.8~1.2
Cylinder/cylinder head
4 8 0.7~1.1 Tighten to crankcase
two-ends bolts
Cylinder head left side bolts 2 6 0.7~1.1
Camshaft sprocket bolts 2 6 1.0~1.5
Valve adjustment fixing nuts 2 5 0.7~1.1 Apply oil to thread
Camshaft chain Tensioner
2 6 0.8~1.2
bolts
A/I fixing flange bolts 4 6 0.8~1.2
Oil pump separator bolts 2 6 0.8~1.2
One-way clutch lock nut 1 22 9.0~10.0 Apply oil to thread
Right crankcase cover bolts 10 6 0.7~1.1
Pulse generator bolts 2 5 0.4~0.6
A.C. generator flange bolts 2 5 0.8~1.2
Flywheel nut 1 12 5.0~6.0
Cooling fan flange bolts 4 6 0.8~1.2
Shroud A/B 2 6 0.7~1.1
Engine oil draining plug bolt 1 12 3.5~4.5
Start motor bolts 2 6 0.7~1.1
Transmission bolts 7 8 2.6~3.0
Gear oil draining plug 1 8 1.0~1.5
Gear oil filling bolt 1 8 1.0~1.5
Driven pulley nut 1 12 5.5~6.0
Driving face nut 1 12 5.0~6.0
Left crankcase cover bolts 8 6 0.8~1.2
Cylinder head holder nuts 4 8 1.8~2.2
Cylinder head cover bolts 4 6 0.8~1.2
Spark plug 1 10 1.0~1.2
Carburetor heat protector
2 6 0.7~1.1
connecting nuts
Exhaust pipe bolts 3 8 3.0~3.6
Exhaust pipe connecting nuts 2 6 1.0~1.4

1-10
SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS
TORQUE VALUES (FRAME)
THREAD DIA TORQUE
ITEM Q'TY REMARKS
(mm) VALUE(Kg-m)
Mounting nut for steering rod 1 25.4 1.0~2.0
Cone seat for steering rod 1 25.4 0.2~0.3
Front wheel shaft nut 1 12 5.0~7.0
Rear wheel shaft nut 1 16 11.0~13.0
Speedometer cable locking
1 5 0.15~0.3
screw
Front shock absorber
4 8 2.4~3.0
mounting bolts
Rear shock absorber upper
1 10 3.5~4.5
connection bolt
Rear shock absorber lower
1 8 2.4~3.0
connection bolt
Brake lever bolts 2 6 0.8~1.2
Front brake hose bolts 4 10 3.3~3.7
Front brake air-bleeding valve 1 6 0.8~1.0
Front brake disc mounting
5 8 2.8~3.2
bolts
Front brake clipper mounting
2 10 3.1~3.5
bolts
RR.brake disc mounting bolts 5 8 2.8~3.2
RR.caliper flange bolts 2 10 3.1~3.5
RR.brake hose bolts 4 10 3.3~3.7
CBS control valve mounting
2 6 1.0~1.4
bolts
Engine suspension bracket
2 10 4.5~5.5 On frame side
bolts
Engine connection bolt 1 10 4.5~5.5 On engine side
Main standard nut 1 10 3.5~4.5
Foot-starting lever bolt 1 6 1.6~1.8
Air cleaner bolts 2 6 1.0~1.4
The torque values listed in above table are for more important tighten torque values. Please see
standard values for not listed in the table.
Standard Torque Values for Reference
TYPE TIGHTEN TORQUE TYPE TIGHTEN TORQUE
5mm bolt、nut 0.45~0.60kgf-m 3mm screw 0.05~0.08kgf-m
6mm bolt、nut 0.80~1.20kgf-m 4mm screw 0.10~0.15kgf-m
8mm bolt、nut 1.80~2.50kgf-m 5mm screw 0.35~0.50kgf-m
10mm bolt、nut 3.00~4.00kgf-m 6mm screw、SH nut 0.70~1.10kgf-m
12mm bolt、nut 5.00~6.00kgf-m 6mm bolt、nut 1.00~1.40kgf-m
8mm bolt、nut 2.40~3.00kgf-m
10mm bolt、nut 3.50~4.50kgf-m

1-11
 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM
Troubleshooting-EFi model
A. Engine cannot be started or difficult to be started
Check and adjustment Fault condition Probable causes

Press the fuel injector feed pipe and confirm

whether there is fuel in the feed pipe
1. Check the fuel amount in the fuel tank
2. Check if the fuel pipe and the vacuum
tube are blocked or not
The fuel supply to the fuel injector is
The fuel injector is not 3. Malfunction of fuel pump relay or wiring
sufficient
4. Malfunction of fuel pump
supplied with sufficient fuel
5. The fuel strainer is blocked or not

Check the spark plug ignition

condition

1. Malfunction of spark plug

2. Spark plug contamination

Week sparks or no spark 3. Malfunction of ECU

Sparks
4. Malfunction of the AC Generator
5. Ignition coil is in open or short circuit
Perform cylinder compression 6. Malfunction of main switch
pressure test

1. Piston ring seized

Normal cylinder compression pressure Low or no compression 2. Malfunction of cylinder valves

pressure 3. Worn cylinder and piston ring
4. Cylinder gasket leakage
Restart the engine 5. Sand hole in the compression parts

1. Malfunction of throttle valve operation

No ignition With signs of ignition but
2. Air sucked into intake manifold
the engine cannot be 3. Incorrect ignition timing
started

Remove and check the

spark plug

1. Contaminated or clogged fuel injector

Dry spark plug Wet spark plug 2. Malfunction of throttle valve operation
3. Malfunction of fuel pressure regulator

1-12
SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS

B. Engine runs sluggish (Speed does not pick up, lack of power)
Check and adjustment Fault condition Probable causes

Accelerate gradually and

check engine RPM

1. Clogged air cleaner

Engine RPM can be Engine RPM cannot be 2. Poor fuel supply
increased increased 3. Clogged exhaust pipe
4. Clogged fuel injector

Check ignition timing

(Using ignition lamp)

Correct ignition timing Incorrect ignition timing

1. Malfunction of ECU
2. Malfunction of AC Generator

Check cylinder compression

pressure (using compression
pressure gauge)

1. Worn out cylinder or piston ring

Normal compression pressure Abnormal compression 2. Cylinder gasket leakage
pressure 3. Sand hole in compression parts
4. Valve deterioration
5. Jammed piston ring
Check if the fuel injector is
clogged or not

Not clogged Clogged 1. Replace the fuel injector

Remove and check the

spark plug

No contamination or discoloration Contaminated or discolored 1. Remove the dirt

2. Incorrect spark plug heat range

Check if the engine is over

heated
1. Worn out piston or cylinder
2. Abnormal fuel injector
Normal Engine overheated 3. Poor fuel quality
4. Carbon deposit in the combustion chamber
5. Abnormal ignition timing
Continually drive in
acceleration or high speed

1. Carbon deposit in the combustion chamber

No knocking Knocking 2. Malfunction of fuel injector
3. Poor fuel quality
4. Abnormal ignition timing

1-13
1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM

C. Engine runs sluggish (especially in low speed and idling)

Check and adjustment Fault condition Probable causes

Check ignition timing

(using ignition lamp)

Normal Abnormal 1. Incorrect ignition timing (malfunction of

ECU or AC Generator)

Check for any air sucked in through

the throttle body insulator gasket

1. Abnormal throttle body insulator gasket.

2. Abnormal throttle body installation
No air sucked in Air sucked in
3. Abnormal inlet pipe gasket
4. Damaged ABV pipe

Remove the spark plug and

check the spark condition

1. Contaminated spark plug

2. Malfunction of ECU
3. Malfunction of AC Generator
Good spark Poor spark
4. Malfunction of ignition coil
5. Open or short circuit in spark plug
leads
6. Malfunction of main switch

D. Engine runs sluggish (High speed)

Check and adjustment Fault condition Probable causes

Check ignition timing

Normal Abnormal 1. Malfunction of ECU

2. Malfunction of AC Generator

Check the fuel pump

supply condition

Good Poor 1. Insufficient fuel in the fuel tank

2. Pressed or clogged fuel pipe

Check if fuel injector clogged

1. Replace the fuel injector

Normal Clogged

1-14
SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS
E. CLUTCH, DRIVING AND DRIVING PULLEY

FAULT CONDITIONS PROBABLE CAUSES

1. Driving belt worn out or deformation

Engine can be started but 2. Driving disk damaged
motorcycle can not be moved. 3. Driving pulley spring broken
4. Clutch ling broken
5. Driving slide-shaft gear groove broken
6. Transmission gear damaged

Engine running and misfire as

motorcycle initial forward moving or 1. Clutch ling spring broken
jumping suddenly (rear wheel rotating 2. Clutch outer stick with clutch balance weights
as engine in running)
3. Connection parts in clutch and shaft worn out or
burned

1. Driving belt worn out or deformation

Poor initial driving ( Poor climbing 2. Balance weight roller worn out
performance)
3. Driving sliding gear shaft worn out
4. Driving disk spring deformation
5. Driving sliding gear shaft worn out
6. Greased in driving belt and sliding gear.

1-15
 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM
LUBRICATION POINTS

Seat lock
Acceleration cable/ Front & rear brake lever pivot

Steering shaft bearing

Speedometer gear / Rear wheel bearing

Side stand shaft Main stand shaft
Front wheel bearing

1-16
SYM 2. MAINTENANCE INFORMATION

PRECAUTIONS IN OPERATION ....... 2-1 IGNITION SYSTEM/SPARK PLUG .. 2-8

PERIODICAL MAINTENANCE CYLINDER COMPRESSION
SCHEDULE ........................................ 2-2 PRESSURE ........................................ 2-9
LUBRICATION SYSTEM .................... 2-3 DRIVING SYSTEM ............................. 2-9
FUEL SYSTEM ................................... 2-4 STEERING SYSTEM ......................... 2-10
AIR CLEANER .................................... 2-5 SUSPENSION SYSTEM .................... 2-10
THROTTLE VALVE OPERATION ...... 2-5 FRONT DISK BRAKE SYSTEM ......... 2-11
CRANKCASE BLOW-BY SYSTEM .... 2-6 DRUM BRAKE SYSTEM .................... 2-13
VALVE CLEARANCE INSPECTION & WHEEL/TIRE ..................................... 2-14
ADJUSTMENT ................................... 2-6 BATTERY ........................................... 2-15
CARBURETOR IDLING SPEED HEADLIGHT ADJUSTMENT .............. 2-15
ADJUSTMENT .................................. 2-7 NUTS、BOLTS TIGHTEN ................. 2-15

PRECAUTIONS IN OPERATION
Specification
Fuel Tank Capacity 7.50L
capacity 950 c.c.
Engine Oil
change 700 c.c.
capacity 180 c.c.
Transmission Gear oil
change 170 c.c.
Clearance of throttle valve 2~6 mm
Spark plug CR7HSA
“F” Mark in idling speed Before TDC 13º / 1700 rpm
Full timing advanced Before TDC 27º / 8000 rpm
Idling speed 1800±100 rpm
Cylinder compression pressure 10.3±0.2:1 kg/cm²
Valve clearance: IN/EX 0.12±0.02 mm
Tire dimension front / rear 100/90-14 / 110/80-14
single Front: 2.00 kg/cm² rear: 2.00 kg/cm²
Tire pressure (cold)
Two persons Front: 2.00 kg/cm² rear: 2.25 kg/cm²
battery 12V6Ah

2-1
2. MAINTENANCE INFORMATION SYM

PERIODICAL MAINTENANCE SCHEDULE

Mainte 1 year
1 Month 3 month 6 month
nance Item Initial 300KM Every12000K
Code Every1000KM Every3000KM Every6000KM
M
1 ☆Air cleaner I C C R
2 ☆Fuel filter I I R
3 ☆Oil filter C C C
4 ☆Engine oil change R I Replacement for every 3000km
5 Tire pressure I I
6 Battery inspection I I
7 Brake & free play check I I
8 Steering handle check I I
9 Cushion operation check I I
10 Every screw tightening check I I
11 Gear oil check for leaking I I
12 ☆Spark plug check or change I I R
13 ☆Gear oil change R Replacement for every 5000km
14 Frame lubrication L
15 Exhaust pipe I I
16 ☆Ignition timing I I
17 ☆Emission check in Idling A I
18 ☆Throttle operation I I
19 ☆Engine bolt tightening I I
20 ☆CVT driving device (belt﹞ I R
21 ☆CVT driving device (roller) C
22 Lights/electrical equipment/mutli-meters I I
23 Main/side stands & springs I I
24 Fuel pipes I I
25 Cam chain I I
26 ☆Valve clearance I A
27 ☆Crankcase blow-by over-flow pipe I Replacement for every 2000km
Code: I ~ Inspection, cleaning, and adjustment R ~ Replacement C ~ Cleaning (replaced if necessary) L ~ Lubrication
Have your motorcycle checked, adjusted, and recorded maintenance data periodically by your SYM Authorized Dealer to
maintain the motorcycle at the optimum condition
The above maintenance schedule is established by taking the monthly 1000 kilometers as a reference which ever comes
first.
Remarks:
1. These marks “☆” in the schedule are emission control items. According to EPA regulations, these items
must be perform normally periodical maintenance following the use r manual instructions. They are
prohibited to be adjusted or repaired by unauthorized people. Otherwise, SYM is no responsible for the
charge.
2. Clean or replace the air cleaner element more often when the motorcycle is operated on dusty roads or in the
Heavily- polluted environment.
3. Maintenance should be performed more often if the motorcycle is frequently operated in high speed and after
the motorcycle has accumulated a higher mileage.
4. Preventive maintenance
a. Ignition system - Perform maintenance and check when continuous abnormal ignition, misfire, after-burn,
overheating occur.
b. Carbon deposit removal - Remove carbon deposits in cylinder head, piston heads, exhaust system when power is
obvious lower than ever.
c. Replace worn out pistons, cylinder head.

2-2
SYM 2. MAINTENANCE INFORMATION

LUBRICATION SYSTEM
Engine Oil Capacity
Caution
 The vehicle must be parked on a level
ground when checking oil capacity.
 Run the engine for 2-3 minutes then
stop, wait about 2-3 more minutes
allowing engine oil to settle before
checking the oil level.
Dipstick
Remove dipstick to check the oil level. If oil
level is below the lower limit mark, add oil to
the specified upper limit mark.
Oil change
Shut off the engine and remove dipstick.
Remove the oil drain plug on the bottom-left
of crankcase to drain oil.
After draining out oil, clean oil plug and its
gasket and reinstall. Replace the gasket if it
is damaged.
Torque value: 3.5~4.5 kgf-m

Caution Oil drain plug

Warm up the engine. This will make the oil

flow out easily. strainer cover
Add oil to the specified capacity.
Oil Viscosity: SAE 10W-30, recommended
using King-Mate serial oil.
Engine oil capacity:
Disassembly: 950cc
Change: 700cc
When checking for oil leak, run the engine at
idle speed for a few minutes, then check oil
capacity with dipstick.
Cleaning the oil strainer
Drain oil from engine, remove the strainer oil strainer
cover, spring and strainer.
If there is an accumulation on the screen,
wash it off with suitable solvent
(recommended using compressed air).
Check O-ring for damage, replace if
necessary.
Reinstall strainer, spring, O-ring and strainer
cover.
Torque value: 1.3~1.7 kgf-m
spring

2-3
2. MAINTENANCE INFORMATION SYM
Gear oil
Gear Oil refilling bolt
Inspection
Check gear oil if leaking.
Park the motorcycle with main stand on flat
level place.
Turn off engine and remove the gear oil
draining plug.
Place a measurement cup under the
draining hole.
Remove the oil drain plug and drain gear oil
into a measurement cup.
Check gear oil if enough.
Replacement
At first, remove the gear oil refilling bolt, and
then remove the draining plug.
Install the draining plug after drained oil out.
Torque value: 0.8~1.2 kgf-m Gear oil draining plug
Caution
Inspect if washer is in good condition.
Replace it with new one if it was deformed
or damaged.
Fill out gear oil to specified quantity from the
engine oil filling hole.
Install the oil filling bolt.
Torque value: 0.8~1.2 kgf-m
Transmission oil capacity: 180 c.c.(170
c.c. for change)
Recommended: genuine SYM HYPOID gear
oil (SAE 85W-140).

Fuel System Fuel pipe

Fuel Pipe
Remove luggage box, side cover, center
cover, body frame cover, and pedal, as well
as front inner box.
Check all pipes, and replace it when they are
deterioration, damage or leaking.
Warning
Gasoline is a low ignition material so any
kind of fire is strictly prohibited as dealing
it.

2-4
SYM 2. MAINTENANCE INFORMATION
screws×9
AIR CLEANER
Element
Remove left side cover.
Remove 9 screws from the air cleaner cover.
Remove element of air cleaner (2 bolts).
Check the element if dirt or damaged.
Replace it with new one if dirt or damaged.

bolts×2

Caution Air cleaner element

 Air cleaner element contains a paper
made filter so do not try to clean it.
 Make sure that the air cleaner cover
had been installed properly after
installation.

THROTTLE VALVE OPERATION

Have a wide open of throttle valve as handle
2~6 mm
bar in any position and release it to let back
original (full closed) position.
Check handle bar if its operation is smooth.
Check throttle valve cable and replace it if
deteriorated, twisted or damaged.
Lubricate the cable if operation is not
smooth.
Measure handle bar free play in its flange
part.
Free play：2~6 mm

Adjustment can be done in either ends. Rubber boot

Secondary adjustment is conducted from top
side.
Remove rubber boot, loosen fixing nut, and
then adjust it by turning the adjustment nut.

Fixing nut
Adjustment nut

2-5
2. MAINTENANCE INFORMATION SYM

Primary adjustment is conducted from button Fixing nut Adjustment nut

side.
Loosen fixing nut, and adjust by turning the
adjustment nut.
Tighten the fixing nut, and check
acceleration operation condition.

CRANKCASE VENTILATION Crankcase blow-by system

Pull out the plug from draining hose to clean
deposits

Caution
When always riding in rainy area or full
throttle position, maintenance period must
be shorted. The deposits can be seen in
the transparent section of draining hose.

2-6
SYM 2. MAINTENANCE INFORMATION

VALVE CLEARANCE INSPECTION TDC mark

AND ADJUSTMENT

Caution
Checks and adjustment must be performed
when engine is cold (below 35℃).

Remove luggage box and front center cover.

Remove the left body cover & left side cover.
Remove cylinder head cap.
Remove the ignition timing check hole on the
cooling fan cover.
With “T” type wrench, turn crankshaft in
clockwise motion so that mark (“T”) on the
generator flywheel aligns with the mark on
the crankshaft, and camshaft is at TDC
position also as same as level of cylinder
head top-end. A single hole on camshaft
sprocket is forward to up. (Piston is at TDC
position in the compression stroke.) Ignition timing mark
Caution
The crankshaft can not be rotated in
counter-clockwise to prevent from damage
so that valve clearance can not be
measured.

Check & adjust valve clearance with feeler Valve clearance adjustment
gauge.
Valve clearance (IN/EX):
0.12±0.02 mm/0.12±0.02 mm
Loosen fixing nut and turn the adjustment
nut for adjustment.
Caution
It has to make sure that valve-rocker arm is
be adjusted to standard level when
adjusting it, and re-check the valve
clearance after tightened the fixing nut.

2-7
2. MAINTENANCE INFORMATION SYM

SPARK PLUG
Appointed spark plug: CR7HSA
Remove luggage box.
Remove body side cover.
Remove front center cover.
Remove spark plug cap.
Clean dirt around the spark plug hole.
Remove spark plug.
Measure spark plug gap.
Spark plug gap: 0.6~0.7 mm
Carefully bend ground electrode of the plug
to adjust the gap if necessary. Spark plug
Screw the park plug into the plug hole with
hands, then tighten the plug with a wrench to
prevent from damaging the spark plug's Side electrode Center electrode
thread.
Torque value: 1.0~1.2 kgf-m
Connect spark plug cap.

0.6~0.7mm

2-8
SYM 2. MAINTENANCE INFORMATION

CYLINDER COPMRESSION PRESSURE

Warn up engine and then turnoff the engine.
Open the seat. Remove the luggage box.
Remove spark plug cap and spark plug.
Install compression gauge.
Full open the throttle valve, and rotate the
engine by means of stepping the
kick-starting lever.
Caution
Rotate the engine until the reading in the
gauge no more increasing. Spark plug cap
Usually, the highest pressure reading will be
obtained in 4~7 seconds by electric start
engine.

Compression pressure: 10.3±0.2:1

Kg/cm² Cylinder
Check following items if the pressure is too pressure gauge
low:
 Incorrect valve clearance
 Valve leaking
 Cylinder head leaking, piston, piston ring
and cylinder worn out
If the pressure is too high, it means carbon
deposits in combustion chamber or piston
head.
Gear teeth
DRIVING SYSTEM
DRIVING BELT Width
Remove left side cover.
Remove mounting bolt located under air
cleaner.
Remove 9 bolts of the engine left crankcase.
Remove the left crankcase cover.
Check if the belt is crack or worn out.
Replace the belt if necessary or in accord
with the periodical maintenance schedule to
replace it.
Width limit: above 17.5 mm Clutch pad

Clutch pad
Start the motorcycle and gradually increase
throttle valve openness to check clutch pad Clutch
operation.
If the motorcycle moves with shaking, then
check its clutch pad for wearing. Replace it
if necessary.

2-9
2. MAINTENANCE INFORMATION SYM

STEERING SYSTEM
Caution
Check all wires and cables if they are
interfered with the rotation of steering
handle bar.
Lift the front wheel out of ground.
Turn handle from right to left and check if
turning is smoothly.
If handle turning is uneven and bending, or
the handle can be operated in vertical
direction, then adjust the handle top bearing.

SUSPENSION SYSTEM
Warning
 Do not ride the motorcycle with poor
shock absorber.
 Looseness, wear or damage shock
absorber will make poor stability and
drivability.
Front shock absorber
Hold front brake lever and press down the
front shock absorber for several times to
check its operation.
Hold front brake lever and push forward the
front shock absorber for several times to
check its locking status.
Check if it is scratched or leaking.
Replace damaged and non-repairable
components.
Tighten all nuts and bolts.

Rear Shock absorber

Press down the rear shock absorber for
several times to check its operation.
Check if it is scratched or leaking.
Replace damaged and non-repairable
components.
Park the motorcycle with main stand.
Start engine and let the rear wheel rotate
after increased engine rpm. Check engine
for any parts loose or shaking. Also check
the engine suspension bushing for wear out.
Replace the bushing if worn out.
Tighten all nuts and bolts.

2-10
SYM 2. MAINTENANCE INFORMATION

FRONT DISK BRAKE SYSTEM Brake hose

BRAKE SYSTEM HOSE

Make sure the brake hoses for corrosion or
leaking oil, and also check brake system for
leaking.

BRAKE FLUID
Check brake fluid level in the brake fluid
reservoir. If the level is lower than the
LOWER limit, add brake fluid to UPPER limit.
Also check brake system for leaking if low
brake level found. Lower limit

Caution
 In order to maintain brake fluid in the
reservoir in horizontal position, do not
remove the cap until handle bar stop.
 Do not operate the brake lever after the
cap had been removed. Otherwise, the
brake fluid will spread out if operated the
lever.
 Do not mix non-compatible brake fluid Brake fluid cap
together.
FILLING OUT BRAKE FLUID Low brake level
Tighten the drain valve, and add brake fluid.
Place the diaphragm in.
Operate the brake lever so that brake fluid
contents inside the brake system hoses.

AIR BLEED OPERATION Bubbles Draining valve

Connect a transparent hose to draining
valve.
Hold the brake lever and open air bleeding
valve. Perform this operation alternative until
there is no air inside the brake system
hoses.
Caution
Before closing the air bleed valve, do not
release the brake lever.
Transparent hose

2-11
2. MAINTENANCE INFORMATION SYM
ADDED BRAKE FLUID Brake fluid cap
Add brake fluid to UPPER limit lever.
Recommended brake fluid: DOT3 or DOT4 Low limit
WELL RUN brake fluid.
Caution
Never mix or use dirty brake fluid to
prevent from damage brake system or
reducing brake performance.

BRAKE LINING WEAR

The indent mark on brake lining is the wear
limitation.
Replace the brake lining if the wear limit
mark closed to the edge of brake disc. Brake ling wear limit

Caution
It is not necessary to remove brake hose
when replacing the brake lining.

Brake disc Brake clipper

Remove the brake clipper bolt, and take out
the clipper.
Caution

Do not operate the brake lever after the

clipper removed to avoid clipping the brake
lining.

Pry out the brake lining with a flat driver if

lining be clipped.

Remove brake lining bolt. Brake clipper bolt

Take out the lining.

Caution Brake lining

In order to maintain brake power balance,

the brake lining must be replaced with one
set.

Bolt

2-12
SYM 2. MAINTENANCE INFORMATION

ABS (Anti-lock Brake System)

ABS is designed to help prevent the wheel from locking up when hard brakes are applied
while running straight. The ABS automatically regulates the brake force. Intermittently
gaining gripping force and braking force helps prevent wheel lock-up and allows stable
steering control while stopping. Brake control function is identical to that of a conventional
scooter. The right brake lever is used for the front brake and the left brake lever for the rear
brake.

Use of non-recommended tires may cause malfunctioning of ABS and can lead to extended
braking distance. The rider could have an accident as a result. Always use recommended
standard tires for this scooter.

When the ABS is functioning, rider may feel a pulsing in the brake lever. This is normal.
ABS does not function at the speed of approx. 5 km/h or below.
ABS does not function if the battery is discharged.

30~40 Nm
30~40 Nm
30~40 Nm
24~30 Nm

24~30 Nm

30~40 Nm

2-13
2. MAINTENANCE INFORMATION SYM

BRAKE LIGHT SWITCH Brake light switch

The brake light switch is to lit up brake light
as brake applied.
Make sure that electrical starter can be
operated only under brake applying.

WHEEL/TIRE
Check if both front and rear tire pressure are
within specification.
Caution
Tire pressure check should be done as cold
tire.

Appointed tire pressure

Tire size Front tire Rear tire
Tire Load for
2.00 2.00
pressure single
as cold Load for
tire two 2.00 2.25
(Kg/cm²) persons
Appointed Tire
Front wheel: 100/90-14
Rear wheel: 110/80-14
Check if tire surface is ticked with nails,
stones or other materials.
Check if tire surface or wall for crack or
damaged, and replace it if necessary.
The tire tread depth can be checked by
visual inspection or depth gauge.
 Replace the tire if tire tread dent or
unusual wearing out.
 The tire should be replaced if the wear
limit mark (△) is in visible.
Measure tire thread depth from tire center
surface.
Replace the tire if the depth is not come with
following specification:
Front tire: 1.5 mm
Rear tire: 2.0 mm
Caution
The wear limit marks (△) are located
around the tire wall even for inspection.
Wear limit indictor 〝△〞mark
2-14
SYM 2. MAINTENANCE INFORMATION

BATTERY
Battery Removal
Remove the 2 screws on the floor panel.
Remove battery cap. (2 nuts)
Battery cables removal:
1. At first, remove the negative “-” cable.
2. Then, remove the positive “+” cable.
3. Remove the battery.

If there is some rust on battery posts, clean it

with steel brush.
Install the battery in the reverse procedures
of removal.
Caution
 If there is rust on the posts very serious,
spray some hot water on the posts.
Then, clean it with steel brush so that
can remove rust for more easily.
 Apply some grease on the posts after
rust removed to prevent from rust again.

HEADLIGHT ADJUSTMENT
Park the motorcycle with the main stand.
Remove the front cover.
Turn on the main switch.
Turn the headlight adjustment screw. And
adjust the headlight beam height.
Then, tighten the adjustment screw after the
beam height in proper position.
Caution
 To adjust the headlight beam follows
related regulations. Headlight adjustment screw
 Improper headlight beam adjustment will
make in coming driver dazzled or
insufficient lighting.

NUTS, BOLTS TIGHTENESS

Perform periodical maintenance in accord
with the Periodical Maintenance Schedule.
Check if all bolts and nuts on the frame are
tightened securely.
Check all fixing pins, snap rings, hose (pipe)
clamps, and wire holders for security.

2-15
SYM 3. LUBRICATION SYSTEM

MECHANISM DIAGRAM .................... 3-1 CLEANING ENGINE OIL STRAINER... 3-3

OPERATIONAL PRECAUTIONS ....... 3-2 OIL PUMP ............................................ 3-4
TROUBLE DIAGNOSIS ...................... 3-2 GEAR OIL ............................................ 3-6
ENGINE OIL ....................................... 3-3

MECHANISM DIAGRAM

Valve rocker
arm Forcedly lubrication

Camshaft

Scoop lubrication

Inner passage
Connecting rod

Forcedly
lubrication

Crankshaft

Oil strainer
Oil pump

3-1
3. LUBRICATION SYSTEM SYM
OPERATIONAL PRECAUTIONS
General Information
 This chapter contains maintenance operations for the engine oil pump, engine oil and
gear oil.
Oil viscosity
Specifications
Engine oil quantity Disassembly 950 c.c.
Replacement 700 c.c.
Oil viscosity SAE 10W-30 or equivalent

Gear Oil Capacity Disassembly 180 c.c.

Replacement 170 c.c.
Oil viscosity of gear oil SAE 85W-140

unit : mm
Items Standard Limit

Inner rotor clearance - 0.12

Clearance between outer
Oil pump rotor and body - 0.12
Clearance between rotor
side and body 0.05~0.10 0.20

Torque value
Engine oil drain plug 3.5~4.5kgf-m
Engine oil screen cover 1.0~2.0kgf-m
Gear oil drain bolt 1.0~1.5kgf-m
Gear oil filling bolt 1.0~1.5kgf-m
Oil pump drive sprocket nut 0.8~1.2kgf-m

TROUBLE DIAGNOSIS
Low engine oil level Dirty oil
 Oil leaking  No oil change in periodical
 Valve guide or seat worn out  Cylinder head gasket damage
 Piston ring worn out  Piston ring worn out
Low Oil Pressure
 Low engine oil level
 Clogged in oil strainer, circuits or pipes
 Oil pump damage

3-2
SYM 3. LUBRICATION SYSTEM
ENGINE OIL
Turn off engine, and park the motorcycle in
flat ground with main stand.
Check oil level with oil dipstick after 3-5
minutes.
Do not rotate the dipstick into engine as
checking.
If oil level is nearly low level, fill out
recommended oil to upper level.

Dipstick

Oil Replacement
Oil drain plug
Caution
Drain oil as engine warmed up so that
make sure oil can be drained smoothly and
completely.
Place an oil pan under the motorcycle, and
remove oil strainer cap.
Make sure if the aluminum washer of the
draining bolt is damaged. If so, replace it
with new one.
Install the oil drain plug and tighten it.
Torque value: 3.5~4.5 kgf-m

CLEANING ENGINE OIL STRAINER

Remove the oil strainer cap.
Remove oil strainer and spring.
Clean oil strainer (recommended using
compressed air to clean dirty foreign).
Check if the strainer and O-ring of the oil
strainer are broken. Replace with new one if
found.
Install the oil strainer and spring.
Install the oil strainer cap and tighten it. Oil strainer cap
Torque value: 1.0~2.0 kgf-m
Fill out oil to the oil filler (Oil viscosity SAE
10W-30).
Engine oil quantity: Replacement 700 c.c.

3-3
3. LUBRICATION SYSTEM SYM
OIL PUMP bolts
Oil Pump Removal
Remove the alternator (refer to chapter10).
Remove the engine right crankcase cover.
Remove the one-way clutch and starting
drive gear (1 nut).

Make sure that the pump axle can be rotated

freely.
Remove the oil pump cover (2 bolts),
Remove the oil pump fixing flat screw .
Remove oil pump body bolts (2 bolts).

Oil Pump Disassembly

Remove the screw on oil pump cover.
Disassemble the oil pump as illustration shown.

Right crankcase cover

Starting gear

Oil pump driving gear

Starting clutch

Oil strainer

Right crankcase

Oil pump outer cover

Oil pump body

Oil pump shaft

Outer rotor
Inner rotor

Oil pump cover

3-4
SYM 3. LUBRICATION SYSTEM
Oil Pump Inspection
Check the clearance between oil pump body
and outer rotor.
Limit: below 0.12 mm

Check clearance between inner and outer

rotors.
Limit: below 0.12 mm

Check clearance between rotor side face

and pump body.
Limit: below 2.0 mm

Oil Pump Re-assembly

Install inner and outer rotors into the pump
body.
Align the indent on driving shaft with that of
inner rotor. Install the driving shaft.
Install the oil pump cover and fixing pin
properly and then tighten screw. (1 screw)

3-5
3. LUBRICATION SYSTEM SYM
Oil Pump Installation
Install the oil pump (2 bolts).

2 bolts

Install oil pump outer cover (2 bolts). oil pump outer cover

2 bolts

Install the starting gear and the alternator. Start drive gear
(Refer to chapter 10)

GEAR OIL Filling bolt

Oil Level Inspection
Park the motorcycle on flat ground with main
stand.
Turn off engine and remove both engine oil
filling bolt and oil draining bolt.

Draining bolt

3-6
SYM 3. LUBRICATION SYSTEM

Remove gear oil filling hole bolt and place a

measurement cup under the draining plug.
Remove the oil draining plug and the pour
gear oil into the measurement cup.
Measure the gear oil quantity if within
standard value.
Add specified gear oil if the oil level too low.
Standard quantity: 180cc.
Replacement:170 cc.

Gear Oil Replacement

Remove the gear oil filling hole bolt and its
draining plug and then drain oil completely.
Install the draining plug and tighten it. (Make
sure if the plug washer is damaged. If so,
replace it with new one.)
Torque Value：1.0~1.5 kgf-m
Add new gear oil (170 c.c.) from the gear oil
filling hole and then install the gear oil filling
hole bolt after added oil. And then, tighten
the bolt.
Torque Value: 1.0~1.5 kgf-m
※Recommended to apply with SYM
HYPOID GEAR OIL (SAE 85W-140)
Start engine and run it for 2~3 minutes.
Turn off engine and check if oil leaking.

3-7
SYM 4. Fuel Injection System

EFi System Diagram ························· 4-1 Crankshaft Position Sensor ··············· 4-17
EFi System Introduction ···················· 4-2 Engine Temperature Sensor / T-Map Sensor
EFi System Components ··················· 4-3 ······················································· 4-18

EFi System Location ························· 4-4 Air By-pass Valve ····························· 4-19

EFi System Component Description ··· 4-5 Fuel Injector····································· 4-19

EFi System Circuit ···························· 4-8 Fuel Pump ······································· 4-19

Precautions in Operation ··················· 4-9 Fuel Unit·········································· 4-20

Troubleshooting ······························· 4-10 Fuel Tank ········································ 4-23

Throttle Body & By-pass Valve Clean Air Cleaner ······································ 4-24
Procedure ········································ 4-14 EFi Troubleshooting & Solution ········· 4-25
5
Fuel Lines ········································ 4-15 EFi Components Malfunction Check &
Ignition System ································ 4-16 Replacement Procedure ···················· 4-53

EFi System Diagram

4-1
5. Fuel Injection System SYM
EFi System Introduction
Based on 4-stroke SOHC engine, electronically controlled fuel injection. The O2 sensor
enhances the efficiency of the catalytic converter, by dynamically controlling the Fuel/Air ratio.

Electronic Fuel Injection Device

Fuel supply devices: fuel tank, fuel pump, fuel filter, and fuel pressure regulator.
Fuel control devices: fuel injector, and ECU.
The fuel is pumped from electrical fuel pump in the fuel tank, to the injector on the inlet pipe.
The fuel pressure regulator keeps the pressure around 2.5 Bar. The signals from ECU enable the
injector to spray fuel into the combustion chamber once each two crankshaft-revolutions. The
excessive fuel flows back to the fuel tank through the fuel pressure regulator. Fuel pump is
placed inside the fuel tank to reduce the working noise, and the complicity of fuel pipes.
Electrically controlled ignition and injection system effectively reduce fuel consumption rate and
pollution.

In traditional gasoline engine, carburetor supplies the fuel. The process is done by the engine
vacuum, and the negative pressure in the carburetor mixes fuel with air. Under this condition,
three major processes are done simultaneously in the carburetor: 1. air quantity measurement,
the determination of fuel quantity, the mix of fuel and air.

Electronic fuel injection system separates the three major processes into three different devices:
1. T-MAP sensor measures the air quantity and temperature and sends the signal to ECU as a
reference. 2. ECU determines the amount of fuel to be injected, according to the default A/F rate.
3. ECU enables the injector to spray appropriate fuel amount. The independence of these three
functions will raise the accuracy of the whole process.

EFi engine uses computer-programmed fuel injection, the main features are:
1. The quantity of fuel injected is determined according to the condition of the engine. The engine
RPM, and throttle position determines the fuel quantity and injection time-length.
2. The quantity of fuel injection, and the determination of injection time length, are all controlled
by 16-bit microcomputer.
3. The fuel pressure regulator maintains a 2.5 Bar pressure difference between inlet pipe and fuel
pipe, raising the accuracy of fuel injection.
4. By measuring the air pressure of inlet pipe, this system gives the vehicle better
accommodation to the environment.
5. Air by-pass system supplies fuel and air to stabilize the idle running, and cold starting.

4-2
SYM 4. Fuel Injection System
EFi System Components

Battery
Main Switch

5V 12V

ECT Sensor Fuel Pump

ECU
Integrated with T-MAP Sensor,
TPS, ABV, and Throttle Body

Ignition Coil

CPS Fuel Injector

4-3
5. Fuel Injection System SYM
EFi System Location

Injector

Fuel Pump

ECU

ECT Sensor

CPS

Fuse

Ignition Coil

O2 Sensor

4-4
SYM 4. Fuel Injection System
EFi System Component Description
Integrated ECU Module
Engine Control Unit (ECU)
 Powered by DC 8~16V, and has 32 terminals connector on the unit.
 The hardware component consists of an 16-bit computer that is its
control center. It contains the functional circuit interface of engine
condition sensing and the driving actuator for the air by-pass valve,
fuel injector, and fuel pump, as well as transistor ignition coil.
 Its major software is a monitor strategy operation program that
includes with controlling strategy, microarray profile and
self-diagnosis programs.

Air Bypass Valve (ABV)

 Its major component is the solenoid valve of high resistance driven
by electric current.
 By means of signals from all sensors, ECU outputs a signal to
control the opening angle of the valve so that can adjust air flowing
to the inlet manifold through the air by-pass valve, and then correct
the idle speed to have engine in normal operation.

T-MAP Sensor
 The major component of the T-MAP sensor is a variable transistor IC.
Its reference voltage is DC 5V, and output voltage range is DC 0~5V.
 It is a sensor of combination by both sensing pressure and
temperature, and can measure the absolute pressure and
temperature in intake process. It also conducts the fuel injection
quantity correction based on environmental temperature and position
level.

Throttle Position Sensor (TPS)

 Its major component is a highly variable resistor. The input voltage
range: 5V DC.
 Located on the side of throttle body. By means of the throttle valve
rotation to cause voltage change in linear, it provides ECU with
current throttle valve openness information. And also, the ECU
determines the most properly fuel injection and ignition timing.

4-5
5. Fuel Injection System SYM

Fuel Injector
 Powered by DC 8~16V, and has 2 terminals connector on the
injector.
 Its major component is the solenoid valve of high resistance driven
by electronic current.
 The two terminals are connected to power source and ground
respective. It is controlled by ECU to determine the injection timing,
and the injector pulse width. Working with 2-valve engine, the unique
2-hole designed injector can provide each intake valve with suitable
fuel quantity to reduce HC emission.

Fuel Pump
 Powered by DC 8~16V, and has 2 terminals connector on the pump.
 The two terminals are connected to power source and ground
respective. The ECU is to control and manage the operation of fuel
pump through electrical power.
 Its major component is a driving fan pump that equipped with a low
electrical consuming DC motor. Powered by 12V voltage and keep
fuel pressure inside the fuel pump in 2.5 bars, which can offer 14
liters of fuel per hour.
 The fuel pump is located inside of the fuel tank, and installed a filter
in front of its inlet so that can prevent from foreign materials sucking
into the fuel pump to damage it and the fuel injector.

Ignition Coil
 Powered by DC 8~16V, and has 2 terminals connector on the coil.
 The two terminals are connected to power source and ground
respective. Its major component is the high transferring rate
transformer.
 Its ignition timing is controlled by computer program. From the
signals of crankshaft position sensor, throttle position sensor, and
engine temperature sensor as well as intake air temperature sensor,
and correspondence with engine speed, then the ECU determines
the ignition timing properly by means of controlling primary current in
ON & OFF operation to create the secondary voltage of
25000~30000V. And then, the voltage triggers the spark plug ignition.
Such kind of ignition system not only can enhance engine
performance to maximum, but also increases fuel consumption
efficiency and improves emission quality.

4-6
SYM 4. Fuel Injection System
ECT Sensor
 Powered by 5V DC from ECU, and has 2 terminals connector on the
sensor. One terminal is for voltage output and the other one for
ground.
 Its major component is the thermo-resistance of negative
temperature coefficient (temperature rises up while resistance falls
down).
 Located on the cylinder head. Correspondence with engine coolant
temperature change, it transferred to voltage signal and sent to ECU
to calculate current temperature. Then, the ECU will correct fuel
injection time and ignition timing according to engine warm up
condition.

CPS
 It does not need power supply, and has 2-signal terminals connector
on the sensor.
 Its major component is the magnetic pickup coil, and its output
voltage range is ±0.8~100V.
 The air gap between the sensor and flywheel must have 0.7~0.9mm.
 By cutting the magnetic field, the magnetic sensor sends an
inductive voltage that is created with the rotation gear (24-1 tooth) on
the flywheel, and the pulse will be sent to the ECU. Then, the ECU
calculates current engine speed and crank position based on the
voltage so that controls fuel injection quantity and ignition timing
properly.

O2 Sensor
 Powered by DC 8~16V, and has 1 terminals connector on the sensor.
the one is for signal output.
 The O2 sensor feeds signal to ECU, and the ECU can control the
air/fuel rate around 14.6. It’s a close –loop control system.
 The catalytic converter reaches the best converting rate when this
14.6 A/F ratio is maintained.
 The heating coil resistance <200kohm (30—45kohm)

4-7
5. Fuel Injection System SYM
Precautions in Operation
General information
Warning
● Gasoline is a low ignition point and explosive materials, so always work in a well-ventilated
place and strictly prohibit flame when working with gasoline.
● Release the fuel pressure before removing the fuel pipe to prevent splashing the fuel.

Caution
● Do not bend or twist throttle cable. Damaged cable will make unstable drive ability.
● When disassembling the fuel system parts, pay attention to O-ring position, replace with new
one as re-assembly.

Fuel pressure release procedure:

Disconnect the fuel pump relay, switch on and press the start switch for a few seconds to crank
the engine.

Specification
Item
Idle speed 1800 rpm
Throttle grip free play 2~6 mm
Fuel pressure 2.5 bar

Torque value
Engine temperature sensor：0.74~0.88 kgf-m
O2 sensor：3.6~4.6 kgf-m

4-8
SYM 4. Fuel Injection System
Troubleshooting
EFi circuit inspection Switch on 1. Burnt Bulb?
2. Blown fuse?
3. Battery voltage too low?
Does the warning lamp goes on for 2 seconds and
NG 4. Poor wire contact on ECU
circuit?
then off?
5. Poor contact on the master
switch?
OK 6. Malfunction of ECU?

Is battery voltage over 12.5V?

NG 1. Abnormal charging circuit?
2. Battery cannot be charged?
3. Short wire circuit?
The voltage difference between battery and ECU is
less than 0.2V.
1. Turn off the main switch. OK
2. Disconnect the ECU connector.
3. Turn on the main switch.
4. With a multi-meter to measure the voltage
between the F4 pin(+) and the H4 pin (-).
NG 1. Abnormal wire connection?
Make sure the voltage difference between
battery and ECU is less than 0.2V.

The voltage difference between battery and active

components is less than 0.2V. OK
1. Turn off the ignition switch.
2. Disconnect the connectors of the fuel injector,
by-pass valve, and ignition coil.
3. Measure the voltage between battery negative NG
side and the each connector (1). 1. Abnormal wire connection?
4. Make sure the voltage difference between
battery and those active components is less
than 0.2V.
OK
The voltage difference between 5V-sensors is less
than 0.2V.
1. Turn off the ignition switch.
2. Disconnect the connectors of throttle valve
position sensor and intake manifold NG 1. Abnormal wire connection?
temperature/pressure sensors. 2. Malfunction of ECU?
3. Turn on the ignition switch.
4. Measure the voltage between the pins(1)(4) of
throttle valve position, and the pins of intake
manifold temperature/pressure sensors (1) (3) is OK
within 5V±0.2V.

The voltage difference between battery and fuel

pump is less than 0.2V.
1. Turn off the ignition switch.
2. Disconnect the fuel pump connector. 1. Abnormal wire connection?
3. With the probes of multi-meter to touch the NG
2. Malfunction of relay?
positive & negative sides of the fuel pump. 3. Malfunction of ECU?
4. Turn on the ignition switch.
5. Record the voltage difference of the fuel pump OK
within 3 seconds.
6. Make sure the voltage difference between
battery and fuel pump is less than 0.2V. END

4-9
 5. Fuel Injection System SYM

Engine cannot be started or difficult to start.

Cannot be started or difficult to start

Does the warning lamp goes 1. Check electrical circuit according to

on for 2 seconds and then off? NG procedure.

OK
1. Connect the diagnostic tool and check
Is the warning lamp out of NG trouble content.
order? 2. Trouble shooting according to the
troubleshooting procedure.

OK

1. No spark on the spark plug?

2. Wet spark plug?
3. Loosen spark plug cap?
Is the electrical circuit abnormal? NG 4. Short in RPM sensor?
5. Loosen high voltage cable?
6. No connection for the by-pass valve?
7. Abnormal ECU?
OK 8. Clean the throttle valve body and ECU
does not be set-up?

1. Low fuel in fuel tank.

2. The fuel pressure of the injector is lower
than 2.5bar.
Is the fuel system abnormal? NG 3. Fuel leaking in pipe?
4. Abnormal regulator?
5. Fuel pump pipe leaking?
6. Abnormal fuel pump?
OK 7. Abnormal fuel injector?

1. No valve clearance?
2. Incorrect ignition timing?
3. Stuck valve?
Is the engine abnormal? NG 4. Worn out cylinder and piston ring?
5. Improperly adjustment of the air
adjustment screw onto the throttle valve
OK body?

END

4-10
SYM 4. Fuel Injection System
Diagnosis of Idle Speed Misfire

Idle speed misfire Does the throttle cable

stuck so could not be
set-up?

1. Connect the Data Scan

and check trouble content Connect the Data Scan
2. Troubleshooting and enter into CO
according to the adjustment at idle menu.
troubleshooting Positive value is for
procedure. enrichment, and negative
value is for lean.

Is the CO value in idle

speed out of set up range?
(0.5%~3.0%)
Is fuel enough?

Does the carbon

Are the battery wires deposited onto the throttle
loose? body?

Replace with
new one for
Is the vacuum pipe Does the by-pass valve confirmation
leaking? operate or out of order?

If the idle speed misfire

problem still can not be solved
after check above related EFI
components item by item,
then check if the other
traditional components on the
engine is in abnormal.

4-11
5. Fuel Injection System SYM

Abnormal CO value
If the system has O2 sensor, the CO value doesn’t have to be adjusted. If the CO value still goes
abnormal, please check O2 sensor first, to see if any malfunction occurred.

Idle speed misfire.

Does the throttle valve cable
stuck so could not be set-up?

Connect the Data Scan

and check trouble content Connect the Data Scan
if there is an abnormal and enter into the data
CO correct value in idle analysis menu.
speed.

Start the engine and warm it

up to 115℃~125℃. Make
sure whether the engine
Is fuel enough? RPM, the openness (75º~90º)
of the by-pass valve, and the
fuel injection time are in
normal.

Switch the Data Scan to

CO adjustment at idle
Are the battery wires menu. Positive value is for
loose? enrichment, and negative
Is the voltage enough? value is for lean.

Is the CO value in idle speed

out of set up range?
(0.5%~3.0%)
Is the vacuum pipe
leaking?

Keep the engine run for 3~5

minutes and then turn off the
engine after confirmed
engine operation in normal.
Conduct Error code erasing
operation.

If the abnormal co correct

value problem still cannot be
solved after check above
related EFI components item
by item, then check if the
other traditional components
on the engine are in
abnormal.

4-12
SYM 4. Fuel Injection System
Throttle Body & By-pass Valve Clean Procedure

● It’s suggested that clean the air by-pass valve before cleaning the throttle body.
● Recommended cleaning frequency: every 6000 km.

Clean procedure:
1. Air by-pass valve：
1. Switch off; disconnect the air tube between the air by-pass valve and connecting pipe.
2. Turn on the engine and keep the idle speed.
3. Spray a little carburetor cleaner into the air by-pass vale for 3~5 minutes. Do not shut
down the engine during cleaning.
4. Connect the air tube.

2. Throttle body:
1. Switch off; remove the throttle body.
2. Spray a little carburetor cleaner into the throttle body.
3. Wipe off the dirty oil with clean cloth or tissue.
4. Dry the throttle body with compressed air and install the throttle body. Connect the
diagnostic tool and switch on.

Idle speed learning:

After performing air by-pass valve or throttle body cleaning, idle speed learning should be carried
out to let ECU know the engine condition well.
When performing the idle speed learning, run the engine at idle speed over 10 minutes after the
engine temperature reaches the working temperature (around 70℃~95℃), and then ECU will get
the parameters from sensors.

4-13
 To this chapter contents

5. Fuel Injection System SYM

Fuel Lines
Regulator

Fuel filter
Fuel
Injector
tank

Fuel

Vacuum
pipe

ECU

Battery

System description:
1. After key-on, all sensors’ signals sent to the ECU first. The electrical fuel pump will be
activated by ECU signal. If the engine did not start for 2~3 seconds, then the fuel pump will
be turned off to save electricity. The pressure regulator maintains the fuel pressure around
2.5 Bar, and the fuel injector spray proper fuel quantity according to the conditions and
environmental coefficient. When key-off or engine stopped, the fuel pumps stop operating.
2. The fuel filter is to filter alien materials so it has to be replaced regularly.
3. Do not let the starting motor keep running when the engine cannot start. It will cause battery
voltage to decrease. If the voltage drops under 8V, the pump will not operate. The
countermeasure will be starting the engine by connecting a new battery or with kick-starter.

4-14
 SYM 4. Fuel Injection System
Ignition System
Transistor
ignition coil
TPS
T-MAP
ECU
ET Sensor Spark
AC Generator CPS plug
Flywheel (24-1 teeth)

Battery

Regulator
rectifier

Principle of operation
The engine is equipped with a computerized ignition control system that collects signals from
CPS, TPS, ET Sensor, and T-MAP Sensor. Then, correspondence with engine RPM, this
8-bit microcomputer in the system controls ignition timing properly. The secondary coil
creates 25000~30000V high voltage to ignite the spark plug by means of the transistor
operation of the primary current entry from the ECU. This can maximize engine performance
and also decrease fuel consumption.

Specification
1. Ignition timing: BTDC 10°/ 1700RPM

2. Spark plug: CR7HSA

Gap: 0.8mm

3. CPS pulse generator coil: 80~160Ω / 20ºC (G/W-LY)

4. Ignition coil
Primary circuit：0.63±0.03Ω(23ºC)

5. Battery Capacity: 12 V 6Ah

4-15
5. Fuel Injection System SYM
Crankshaft Position Sensor

No tooth

ECU signal Closed

Secondary TDC TDC

voltage Ignition

Sensor signal Time

Description:
The magnetic field type sensor generates a
voltage signal to calculate engine speed with
ACG gear ring (24-1 tooth).

There is one tooth every 15 degree on the gear

ring. But, one of the teeth is blank for the TDC
calculating base.

4-16
SYM 4. Fuel Injection System
Engine Temperature Sensor / T-Map Sensor

Engine temperature sensor:

According to the semiconductor’s characteristic, the sensor detects the temperature of engine oil
and metal parts and then sends a voltage signal to the ECU. On this base, the ECU can correct
fuel injection and ignition timing.

NTC- Negative Temperature

Coefficient Resistor

T-MAP Sensor：
Sensor combined both pressure and NTC can detect the absolute pressure and temperature in
the intake manifold, and then provides the ECU with signal for adjustment fuel injection quantity
based on environmental temperature and air pressure difference from elevation level change.

mv

-40ºC 140ºC

4-17
5. Fuel Injection System SYM

Air By-pass Valve

Description:
ECU receives all sensors’ signals to control the throttle valve openness with PWM, and adjust
airflow through the by-pass valve of the intake manifold. It can adjust idle speed for a stably
running engine.

1. When engine cold starting---the by-pass valve open for a while to increase airflow and to
stabilize engine idle speed within initial starting
2. Warm-up---when engine oil is in low temperature condition, the by-pass valve adjusts airflow
according to engine temperature (engine oil temperature), and raises idle speed.
3. Speed decreasing--- ECU controls the by-pass valve in correspondence with throttle
operation, to provide inlet pipe with proper airflow quantity. Such operation will smooth the
engine rpm reduction process, preventing the engine from stalling, excessive negative
pressure, and also reduce HC emission.

Fuel Injector
The injector provides intake valve a fuel jet. This can reduce the pollution of HC. The shortened
version of fuel pump plate makes its size more compact, and sturdier against shocks. ECU
signal controls the regulator to maintain 2.5 bars between the fuel pressure and the air pressure
of inlet pipe. Through controlling the time length of injection under steady fuel pressure, the
system can optimize the fuel injection quantity according to different engine workloads.

Fuel Pump
Electrical fuel pump is mounted inside the fuel tank. The power source is DC current provided
and controlled by ECU; the pump can provide 14L/hour under the pressure of 2.5 bars.

4-18
SYM 4. Fuel Injection System
Fuel Pump / Fuel Unit
Removal
Removal
Open the seat.
Remove 5 sockets in the rear carrier & fuel
tank cover.

Remove the body cover.

Coupler
Fuel pipe

Disconnect the fuel pump couplers.

Disconnect the fuel unit couplers
Remove the fuel pipes.

Fuel unit coupler

6 bolts

Remove the fuel pump lock bolts.

4-19
5. Fuel Injection System SYM
Remove the fuel pump and fuel unit. Oil seal
Caution
● Check if the oil seal is deformed or
damaged. Replace it with new one if
necessary.

Check if the fuel filter is contaminated or Fuel filter

clogged. Replace it with new one if necessary.

Fuel pressure regulator

Remove the fuel unit.

Check the oil seal of fuel unit for any damage
or deformation.

Installation
Install in the reverse order of removal.
Caution
● Do not bend the fuel unit float arm
● Do not fill out too much fuel in the tank.
● Align the assembly mark when installing
the fuel pump and fuel unit.
● Replace the oil seal if any damage or
deformation is found.

4-20
SYM 4. Fuel Injection System
Inspection：
Disconnect the fuel pipe from the fuel injector. Fuel pressure gauge
Connect the fuel pressure gauge to check the
fuel pressure.
Caution
● Make sure the fuel pressure is normal
(2.5 bar).
● Always release the fuel pressure before
removing the fuel pipe to prevent the fuel
from splashing.

Fuel pipe
Special tool：
Fuel pressure gauge SYM-HT07010
Replace the fuel pump with new one if 4 bolts
malfunction is confirmed.

Fuel Tank
Removal
Disconnect the fuel pump and the fuel unit
coupler.
Remove fuel pipe.
Remove the fuel cut valve pipe.
Remove the fuel tank (4 lock bolts).

Installation Fuel cut valve

Install in the reverse order of removal.

Caution
● Make sure the fuel in the tank is not too
much before removing the fuel tank.
● Replace the fuel tank if there is any
damage or leakage.

4-21
5. Fuel Injection System SYM
Air Cleaner 9 screws
Remove the air cleaner cover (9 screws).

Remove the air cleaner element .

Element
Caution
● The air cleaner is paper-base; please
blow it clean with compressed air. Don’t
use water or other solvent
● Replace it with new one if the dirt cannot
be removed.

Installation
Install in the reverse order of removal.

4-22
SYM 4. Fuel Injection System
EFi Troubleshooting and Solution
 Electronic fuel injection（EFi）system fault warning light
After the main switch is on, the EFI indicator will be light. If the vehicle existing problems, the
EFI indicator will light up all the time after the electrical starter button is on. When the problem
is eliminated, restart the electrical starter button, the EFI indicator will light out automatically.

Error Code Message and Solution Operation

DTC Monitoring
Component DTC
Description Stratege

Engine Coolant Temperature

P0117 Signal shorted to ground
Circuit Low Input
Engine Coolant
Signal shorted to Battery or
Engine P0118 Temperature Circuit High
circuit open
Coolant Input
1
Temperature Engine coolant temperature
P0116 Tco out of range
sensor sensor range problem

Engine coolant temperature

P0116 Stuck Tco Signal
sensor stuck problem

Intake Air Temperature

P0112 Signal shorted to ground
Circuit Low Input
Intake Air Temperature Signal shorted to Battery or
P0113
Intake Air Circuit High Input circuit open
2 Temperature Intake air temperature
P0111 TIA out of range
sensor sensor range problem

Intake air temperature

P0111 Stuck TIA Signal
sensor performance problem

Manifold absolute pressure

P0107 Signal shorted to ground
sensor Circuit Low Input
Manifold Manifold absolute pressure
P0108 Signal shorted to Battery or open
Absolute sensor High Input
3
Pressure Manifold absolute pressure
sensor P0106 MAP Signal out of range
sensor range problem
Manifold absolute pressure
P0106 Stuck MAP Signal
sensor stuck problem

O2 Sensor Signals circuit

P0131 Signal shorted to ground
low Voltage
O2 Sensor
4
Signals
O2 Sensor Signals circuit
P0132 Signal shorted to Battery
High Voltage

4-23
5. Fuel Injection System SYM
O2 Sensor Signals circuit
P0134 Signal open circuit
open

O2 Sensor Signals out

P2A00 Signal out of range
problem

02 Sensor Circuit Slow

P0133 Signal Plausibility
Response

Throrrle position sensor Signal shorted to ground/

Throttle P0122
circuit low or circuit open circuit open
5 Position
Throrrle position sensor
Sensor P0123 Signal shorted to Battery
circuit high
Signal shorted to battery or
P0261 Fuel Injector circuit low
open
6 Fuel Injector
P0262 Fuel Injector circuit High Signal shorted to ground

Step motor circuit lower or Signal shorted to ground or

P0508
circuit open open
Idle Air
P0509 Step motor circuit high Signal shorted to Battery
7 Control
system
Step motor circuit
P0519 Signal Plausibility
Plausibility problem

Primary coil low/ no Signal shorted to ground or

Ignition Coil P2300
current open
8 Control
System P2301 Primary coil overcurrent Signal shorted to Battery

O2 sensor heater circuit

P0031 Signal shorted to ground
lower
O2 sensor heater circuit
P0032 Signal shorted to Battery
O2 Sensor high
9
Heater System O2 sensor heater circuit
P0131 Signal open circuit
open
02 Sensor Heater Circuit O2 sensor heater
P0135
Malfunction Plausibility
CrankShaft
CrankShaft Position
10 Position P0335 Present crank error
Sensorr circuit open
Sensor
Ssignal shorted to groung Signal shorted to ground or
P0231
or open open
11 Fuel Pump
P0232 Steep motor circuit high Signal shorted to Battery

4-24
 SYM 4. Fuel Injection System
Engine Over
12 P0217 Engine Overtemp Condition None
Temperature

P0562 System voltage low None

13 Battery
P0563 System voltage high None

Mis Fire A
14 P0314 Cylinder Misfire Detected Mis fire detected
diagnosis

Mis Fire B
15 P0314 Single cylinder misfire Mis fire detected
diagnosis

Electronic control unit connector illustration:

Power supplies 6
Sensors inputs 6
Logic inputs 4
Differential
2
inputs
Power outputs 12
Communication 2
cConfigurable IO 2
X34 X33 X32 X31 X30 X29 X28 X27 X26
Function description
Vehicle SENSOR (H)EGO SENSOR
- Kill Sw VBD CAN_L SAV
Speed supply SENS_UP GROUND

FSU/FP (H)EGO
FAN relay - RPM OUT - CAN_H VBK -
relay SENS_DN

X17 X16 X15 X14 X13 X12 X11 X10 X9

X25 X24 X23 X22 X21 X20 X19 X18

start IGNITION
VR- CHTS CPV SSW MIL PGND2
relay COIL

head
Injector HEGO
VR+ lamp START SW - - PGND1
PI HEAT_UP
relay
X8 X7 X6 X5 X4 X3 X2 X1

4-25
SYM 5. REMOVAL OF ENGINE

MECHANISM DIAGRAM ...................... 5-1 ENGINE SUSPENSION FRAME .......... 5-7

OPERATIONAL PRECAUTIONS ......... 5-2 INSTALLATION OF ENGINE ............... 5-8
ENGINE REMOVAL ............................. 5-3
REMOVAL OF ENGINE SUSPENSION
BUSHING ............................................. 5-6
MECHANISM DIAGRAM

3.5~4.5kgf-m

4.5~5.5kgf-m

4.5~5.5kgf-m

2.4~3.0kgf-m

4.5~5.5 kgf-m

5-1
5. REMOVAL OF ENGINE SYM
OPERATIONAL PRECAUTIONS
General Information
 Engine must be supported by a bracket or adjustable tool in height.
 The following parts can be serviced with the engine installed on the frame.
1. Carburetor
2. Driving disk, driving belt, clutch, and transporting disk
3. Final reduction gear mechanism

Specification
Item Specification
Replacement 950 c.c.
Engine Oil Capacity
Disassemble 700 c.c.
Replacement 180 c.c.
Gear Oil Capacity
Disassemble 170 c.c.
Torque Values
Engine suspension bolt (frame side) 4.5~5.5kgf-m
Engine suspension nut (engine side) 4.5~5.5kgf-m
Bolt of rear shock absorber upper connection 3.5~4.5kgf-m
Bolt of rear shock absorber lower connection 2.4~3.0kgf-m

5-2
SYM 5. REMOVAL OF ENGINE
ENGINE REMOVAL Auto by-start
connector
Open the seat.
Remove the rear carrier (3 bolts ).
Remove the luggage box assembly (4
bolts ). Pulse
generator
Remove the body cover (4 screws, 3 bolts). connector
Remove the power connector of auto by-
start.
Remove the generator connector and pulse
generator connector.
Generator connector

Remove the starter motor wire on the Starter

magnetic switch.

Starter magnetic switch

Remove the spark plug cap.

Spark plug cap

Remove the vacuum hose, and throttle valve

cable from the ECU SET.
Loose the strap screw of the air cleaner
guide, and remove the air cleaner guide
Remove the throttle cable

5-3
5. REMOVAL OF ENGINE SYM

Remove the fuel tube. Remove cylinder Fuel tube

folder
head TEMP sensor connector.
Start engine for the pipeline to be exhausted
Within the residual pressure, the engine
flameout, relaxing fuel tube folder,
open for fuel tube.
Caution
● Demolition for the pipeline will be
required for residual pressure in the
pipeline to divest, or use the folder
surrounds the tubing to prevent petrol
GYL head TEMP sensor connector
splash.

Bolts×3
Remove the exhaust muffler (Bolts ×
3, Cap Nuts × 2).

Cap nuts×2

Remove the rear wheel (Nut × 1).

Nut ×1

2 bolts
Remove the air cleaner connection bolts (2
bolts).

5-4
SYM 5. REMOVAL OF ENGINE
Remove the rear brake nut. Brake nut
Remove the rear brake caliper
Remove the rear shock absorber lower bolt.

Shock absorber lower bolt

Loose the strap screw of engine left guide,
and then remove the engine left guide.

Strap screw of guide

Remove the engine suspension nuts and

Engine suspension nuts
bolts (engine side), and then remove the
engine.
Caution
 With a bracket to support the engine to
prevent from it damage by falling down
as removing the engine.

Check if the engine suspension, rear shock Bushing

absorber bushing, and cushion rubber for
damage. Replace them with new ones if
so.

5-5
5. REMOVAL OF ENGINE SYM
REMOVAL OF ENGINE
SUSPENSION BUSHING
If engine suspension frame and the cushion
rubber of rear shock absorber bushing
damaged. Then, with the bushing remover /
presser, Φ28mm &Φ20mm, to press the
bushing out, and replace it with new one.

Engine suspension bushing: Φ28mm

Rear shock absorber bushing: Φ20mm

Pressing out
Place the detent section of the bushing
remover toward the bushing, and drive both
the pressing ring and bolt in to press the
bushing out.

Pressing In
Place the flat section of the remover toward
the bushing, and then drive the bushing,
pressing ring, and bolt in to install the
bushing.

5-6
SYM 5. REMOVAL OF ENGINE
ENGINE SUSPENSION FRAME
Bolt of engine suspension frame (left side)
Removal
Remove the left side bolt of engine
suspension frame.

Remove the right side bolt of engine

suspension frame.

Bolt of engine suspension

frame (right side)

Check if the engine suspension frame

bushing and cushion rubber for damage. If
so, replace with new ones.

Installation
Tighten the bolts and nuts of engine
suspension frame.

Engine suspension frame nut:

Torque Value: 4.5~5.5 kgf-m

5-7
5. REMOVAL OF ENGINE SYM
INSTALLATION OF ENGINE
Check if the bushings of engine suspension
frame and shock absorber for damaged. If so,
replace with new ones.
Install the engine according to the reversing
order of removal.

Caution
 Notice both feet and hands safety for
squeezing as engine installation.
 Do not bent or squeeze each wires or Engine suspension nuts
hose.
 Route all cables and wires in accordance
with the routine layout.
Engine suspension nut:
Torque Value: 4.5~5.5kgf-m

Rear shock absorber bolt:

Torque Value: Top: 3.5~4.5kgf-m
lower: 2.4~3.0kgf-m

Rear wheel axle nut:

Torque Value: 11.0~13.0kgf-m Shock absorber lower bolt

Rear wheel axle nut×1

5-8
 SYM 6. CYLINDER HEAD/VALVE

MECHANISM DIAGRAM .................... 6-1 CYLINDER HEAD INSPECTION ......... 6-7

PRECAUTIONS IN OPERATION ....... 6-2 VALVE SEAT INSPECTION AND
TROUBLE SHOOTING....................... 6-3 SERVICE.............................................. 6-9
CAMSHAFT REMOVAL ..................... 6-4 CYLINDER HEAD REASSEMBLY ....... 6-11
CYLINDER HEAD REMOVAL ............ 6-6 CYLINDER HEAD INSTALLATION ...... 6-12
CYLINDER HEAD DISASSEMBLY .... 6-6 VALVE CLEARANCE ADJUSTMENT .. 6-13
MECHANISM DIAGRAM
1.0~1.4 kgf-m

1.0~1.4 kgf-m

0.7~1.1 kgf-m

1.8~2.2 kgf-m

1.0~1.4 kgf-m 1.0~1.4 kgf-m

6-1
6. CYLINDER HEAD/VALVE SYM
PRECAUTIONS IN OPERATION
General Information
 This chapter is contained maintenance and service for cylinder head, valve, and camshaft
as well as valve rocker arm.
 Cylinder head service cannot be carried out when engine is in frame.

Specification unit: mm

Item Standard Limit

Compression pressure 10.3 ± 0.2:1 kg/cm² -

Intake 20.231 20.570

Camshaft Height of cam lobe
Exhaust 19.907 19.410

Rocker ID of valve rocker arm 10.00~10.015 10.10

arm OD of valve rocker arm shaft 9.972~9.987 9.910

Intake 4.970~4.980 4.900

OD of valve stem
Exhaust 4.955~4.970 4.900

ID of Guide 5.00~5.012 5.030

Clearance between Intake 0.020~0.042 0.080

Valve valve stem and guide Exhaust 0.030~0.057 0.100

Free length of valve Outer 35.250 -

spring Inner 32.410 -

Valve seat width 1.000 1.600

Torque Value
Cylinder head cover bolt 0.8~1.2kgf-m
Cylinder head bolt (LH) 0.7~1.1kgf-m
Sealing screw of timing chain auto-adjuster 0.8~1.2kgf-m
Bolt of timing chain auto-adjuster 1.0~1.4kgf-m
Cam sprocket bolts 0.7~1.1kgf-m (apply with oil on bolt thread & seat)
Spark plug 1.0~1.4kgf-m
Cylinder head temperature sensor 1.0~1.4kgf-m

TOOLS
Special service tools
Valve reamer: 5.0mm
Valve guide driver: 5.0mm
Valve spring compressor

6-2
SYM 6. CYLINDER HEAD/VALVE
TROUBLE SHOOTING
Engine performance will be effected by troubles on engine top end. The troubles usually can
be determinate or by performing cylinder compression test and judging the abnormal noise
generated.

Rough Idle
Low compression pressure.

Low compression pressure

1. Valve
 Improper valve adjustment.
 Burnt or bended valve.
 Improper valve timing.
 Valve spring damaged.
 Valve carbon.
 Poor sealing on valve seat.
 Improper spark plug installation.
2. Cylinder head
 Cylinder head gasket leaking or damage.
 Tilt or crack cylinder surface.
3. Piston
 Piston ring worn out.

High compression pressure

 Too much carbon deposit on combustion chamber or piston head.

Noise
 Improper valve clearance adjustment
 Burnt valve or damaged valve spring
 Camshaft wear out or damage
 Cam chain wear out or looseness
 Auto-adjuster wear out or damage of cam chain
 Camshaft sprocket wear out
 Rocker arm or rocker arm shaft wear out

White smoke
 Valve guide or valve stem wear out
 Valve stem seal wear out

6-3
6. CYLINDER HEAD/VALVE SYM
CAMSHAFT REMOVAL Blow-by hose
Remove the shroud of the engine.
Remove the crankcase blow-by system hose
from the cylinder head.
Remove the cylinder head cover 4 bolts and
then remove the cylinder head cover.

Shroud 4 bolts

Loosen the screw of camshaft chain adjuster screw

and remove O-ring.
With a flat screwdriver to tighten the screw of
camshaft chain adjuster in a clockwise
motion for release adjuster.

camshaft chain adjuster

Turn the flywheel in counter-clockwise Hole

motion with T type wrench until the “T” mark
on flywheel aligned with the mark on the
crankcase so that the hole on the camshaft
sprocket is forward up and piston is at TDC
position.

TDC mark

Remove camshaft holder nut and washer.

Caution
Loosen the nuts diagonally by 2-3
sequences.

4 nuts

6-4
SYM 6. CYLINDER HEAD/VALVE

Remove the camshaft holder and rocker arm

set.
Remove the camshaft chain from the
camshaft sprocket.
Remove the cylinder head.

Camshaft Inspection
Inspect cam lobe height for damaged.
Service Limit
IN: Replacement when less than 20.570mm
EX: Replacement when less than 19.410
mm
Inspect the camshaft bearing for looseness
or wear out. If any, replace whole set of
camshaft and bearing.

Measure the valve rocker arm I.D.

Service Limit: Replace when it is above
10.100 mm

Measure the active O.D. of the valve rocker

arm shaft .
Service Limit: Replace when it is above
9.910 mm
Calculate the clearance between the rocker
arm shaft and the rocker arm.
Service Limit: Replace when it is above
0.10 mm

6-5
6. CYLINDER HEAD/VALVE SYM

CYLINDER HEAD REMOVAL

Remove the engine (refer to Chapter 5).
Remove the cooling fan cover.
Remove the engine shroud .

Remove the camshaft sprocket.

Remove the 2 cylinder head mounting bolts

from cylinder head left side cover.
Remove cylinder head gasket and 2 dowel dowel pins
pins.
Remove chain plate.
Clean up residues from the matching
surfaces of cylinder and cylinder head.

Caution
 Do not damage the matching surfaces of
cylinder and cylinder head.
 Avoid residues of gasket or foreign
materials falling into crankcase as
cleaning. Chain plate
Cylinder head gasket

CYLINDER HEAD DISASSEMBLY

Use a valve compressor to press the valve
spring.

6-6
SYM 6. CYLINDER HEAD/VALVE

After removed valve cotters, release the valve cotters

compressor and then take out spring retainer,
valve spring and valves.

Caution
In order to avoid to loosing spring tension,
do not compress the spring too much. Its
length is based on the installation of latch.

Special Service Tool: Valve spring compressor.

Remove valve stem guide seal.

Clean carbon deposits in combustion chamber.
Clean residues and foreign materials on
cylinder head matching surface.

Caution
Do not damage the matching surface of
cylinder head.

CYLINDER HEAD INSPECTION

Check if spark plug and valve holes are crack.
Measure cylinder head flat with a
straightedge and flat feeler gauge.
Service limit: 0.05mm

Valve spring free length

Measure the free length of intake and
exhaust valve springs.
Standard
Outer : 35.250 mm
Inner : 32.410 mm

The narrow pitch of the spring shall face to the

combustion chamber.

6-7
6. CYLINDER HEAD/VALVE SYM
Valve stem
Check if valve stems are bend, crack or burn.
Check the operation condition of valve stem
in valve guide, and measure & record the
valve stem outer diameter.
Service Limit: IN→ 4.900mm
EX→ 4.900mm

Valve guide

Caution
Before measuring the valve guide, clean
carbon deposits with reamer.
Special Service Tool: 5.0mm valve guide
reamer
Measure and record each valve guide inner
5.0mm valve guide reamer
diameters.
Service limit: 5.030mm
The difference that the inner diameter of
valve guide deducts the outer diameter of
valve stem is the clearance between the
valve stem and valve guide.
Service Limit: IN→ 0.08mm
EX→ 0.10mm

Caution
If clearance between valve stem and
valve guide exceeded service limit, check
whether the new clearance that only
replaces new valve guide is within service
limit or not. If so, replace valve guide.
Correct it with reamer after replacement.
If clearance still exceeds service limit after
replaced valve guide, replace valve stem too.

Caution
It must correct valve seat when replacing
valve guide.

Valve guide replacement Valve guide driver

Heat up cylinder head to 100~150 ℃ with 5.0mm
heated plate or toaster.

Caution
 Do not let torch heat cylinder head
directly. Otherwise, the cylinder head
may be deformed as heating it.
 Wear on a pair of glove to protect your
hands when operating.

6-8
SYM 6. CYLINDER HEAD/VALVE
Hold the cylinder head, and then press out old
valve guide from combustion chamber side.
Valve guide driver
Tool: Valve guide driver 5 mm 13 mm 5.0mm
(0.15in)
Caution
 Check if new valve guide is deformation
after pressed it in.
 When pressing in the new valve guide,
cylinder head still must be kept in
100~150 ℃.

Adjust the valve guide driver and let valve

guide height is in 13mm.
Press in new valve guide from rocker arm side.
Tool: Valve guide driver 5 mm
Wait for the cylinder head cooling down to
room temperature, and then correct the new
valve guide with reamer.

Caution Valve guide reamer 5.0mm

 Using cutting oil when correcting valve

guide with a reamer.
 Turn the reamer in same direction when
it be inserted or rotated.
Correct valve seat, and clean up all metal
residues from cylinder head.
Special tool: Valve guide reamer 5 mm
VALVE SEAT INSPECTION AND
SERVICE
Clean up all carbon deposits onto intake and
exhaust valves.
Apply with emery slightly onto valve contact
face. Grind valve seat with a rubber hose or
other manual grinding tool.

Caution
 Do not let emery enter into between valve
stem and valve guide.
 Clean up the emery after corrected, and
apply with red paint onto contact faces of
valve and valve seat.

Remove the valve and check its contact

face.
Valve seat
Caution width
Replace the valve with new one if valve
seat is roughness, wear out, or incomplete
contacted with valve seat.
If the valve and the valve seat still can not
be matched sealing after grinded, replace it
with new one.

6-9
6. CYLINDER HEAD/VALVE SYM

Valve seat inspection

Roughness
If the valve seat is too width, narrow or rough,
correct it.
Valve seat width
Service limit: 1.6mm
Check the contact condition of valve seat.
Valve seat grinding 45°
The worn valve seat has to be grinded with
valve seat chamfer cutter.
Use 45° valve seat chamfer cutter to cut any
rough or uneven surface from valve seat.

Caution
After valve guide had been replaced, it Old valve seat width
has to be grinded with 45° valve seal
chamfer cutter to correct its seat face.
32°
Use 32° cutter to cut a quarter upper part
out.

Use 60° cutter to cut a quarter lower part out.

Remove the cutter and check new valve
seat.
Old valve seat width

60°
Use 45° cutter to grind the valve seat to
specified width.

Caution 1.0mm

Make sure that all roughness and

uneven faces had been grinded.

Grind valve seat again if necessary.

45°

6-10
SYM 6. CYLINDER HEAD/VALVE

Coat the valve seat surface with red paint.

Install the valve through valve guide until the Contact surface too high
valve contacting with valve seat, slightly
press down the valve but do not rotate it so Old valve seat
that a seal track will be created on contact width
surface.

Caution 32°
The contact surfaces of valve and valve
seat are very important to the valve
sealing capacity.

If the contact surface too high, grind the Contact surface Old valve seat
too low
valve seat with 32° cutter. width
Then, grind the valve seat with 45° cutter to
specified width.

If the contact surface too low, grind the valve

seat with 60° cutter.
Then, grind the valve seat with 45° cutter to 60°
specified width.

After the valve seat grinded, coat valve seat

surface with emery and then slightly press
the grinded surface.
Clean up all emery coated onto cylinder and
valve after grinded.

CYLINDER HEAD REASSEMBLY

Valve cotters
Lubricate valve stem with engine oil, and Valve stem
then insert the valve into valve guide. oil seal
Install new valve stem oil seal. Valve spring
retainer
Install valve springs and retainers.

Caution
The closed coils of valve spring should face Valve spring
down to combustion chamber. Valve

6-11
6. CYLINDER HEAD/VALVE SYM

Use valve spring compressor to press valve

spring.
Install valve split locks and release the valve
compressor.

Caution
In order to avoid to loosing spring tension,
do not compress the spring too much. Its
length is based on the installation of latch.

Special tool: valve spring compressor

Tap valve stem to make valve retainer and

valve stem sealing properly.
Caution
Place and hold cylinder head on to working
table so that can prevent from valve
damaged.

Lock pins Cylinder head gasket

CYLINDER HEAD INSTALLATION

Install the lock pins and new cylinder head
gasket onto the cylinder head.
Install the camshaft chain plate.

Chain plate

With T type wrench to turn crankshaft in a

clockwise motion so that the “T” mark on the
flywheel aligns with the mark on crankcase.
(piston is at TDC position)
Place the TDC marks of the cam sprocket at
same level of the top-end of cylinder head.
The other single hole of the cam sprocket is
in upward. Then, install the cam chain onto
the cam sprocket.

Install the cylinder head.

6-12
SYM 6. CYLINDER HEAD/VALVE

VALVE CLEARANCE ADJUSTMENT

Loosen valve clearance adjustment nuts and
bolts located on valve rocker arm.
Measure and adjust valve clearance with
Especial tool
feeler gauge.
After valve clearance had been adjusted to
standard value, hold adjustment bolt and
then tighten the adjustment nut.
Standard Value: 0.12 ± 0.02mm
With flat screwdriver, turn the cam sprocket
adjuster in counter-clockwise motion so that
the adjuster is pushed out to contact the cam
chain plate tightly. Apply with oil onto a new
O-ring and then install it onto the adjuster
hole. Tighten the bolt cap of the adjuster
adjustment hole.
Caution
The O-ring must be installed into glove.
Replace the O-ring of the cylinder head with
new one. Install the cylinder head.

Tighten the cylinder head lock bolts.

Connect the blow-by hose onto the cylinder
head.
Blow-by hose
Install the engine onto the engine frame.
(Refer to Chapter 5)

Spark plug cap 4 bolts

6-13
SYM 7. CYLINDER/PISTON

MECHANISM DIAGRAM .................... 7-1 PISTON REMOVAL............................ 7-5

PRECAUTIONS IN OPERATION ....... 7-2 PISTON RING INSTALLATION .......... 7-7
TROUBLE DIAGNOSIS ...................... 7-2 PISTON INSTALLATION .................... 7-8
CYLINDER REMOVAL ....................... 7-3 CYLINDER INSTALLATION .............. 7-8
MECHANISM DIAGRAM
0.8~1.2kgf-m

7-1
7. CYLINDER/PISTON SYM
PRECAUTIONS IN OPERATION

General Information
 Both cylinder and piston service cannot be carried out when engine mounted on frame.

Specification unit: mm
Item Standard Limit

ID 52.395~52.415 52.50

Bend/wrap age Less than 0.05 0.050

Cylinder
Roundness Less than 0.01 0.050

Cylindrical Less than 0.05 0.050

Clearance between Top ring 0.05~0.105 0.145

piston and rings 2nd ring 0.05~0.105 0.145

Top ring 0.100~0.2500 0.500

Ring-end gap 2nd ring 0.300~0.500 0.750

Piston/
Oil ring 0.200~0.700 －
Piston ring
OD of piston 52.385~52.405 52.310
Lower-end up 7mm
Piston OD measurement position of piston skirt
－
Clearance between piston and
cylinder 0.005~0.015 0.100

ID of piston pin hole 15.002~15.008 15.040

OD of piston pin 14.994~15.00 14.96

Clearance between piston and piston pin 0.002~0.014 0.020

ID of connecting rod small-end 15 15.06

TROUBLE DIAGNOSIS

Low Or Unstable Compression Pressure  Piston pin hole and piston pin wear out.
 Cylinder or piston ring worn out. Smoking in Exhaust Pipe
 Compress pressure to high.  Piston or piston ring worn out.
 Too much carbon deposited in  Piston ring installation improperly.
combustion chamber and piston.  Cylinder or piston damage.5
Knock or Noise
 Cylinder or piston ring worn out. Engine Overheat
 Carbon deposits on cylinder head  Carbon deposits on cylinder head top
top-side. side.

7-2
SYM 7. CYLINDER/PISTON
CYLINDER REMOVAL 2 bolts
Remove cylinder head. (refer to chapter 6) Cylinder
Remove 2 bolts and then take out the cam
chain auto-adjuster.

Cam chain Cam chain

guide auto-adjuster

Remove cam chain plate.

Remove cylinder.

Remove cylinder gasket and lock pins

Clean the residues attached onto the

matching surfaces of cylinder and
crankcase.

7-3
7. CYLINDER/PISTON SYM

Cover the holes of crankcase and cam chain

with a piece of cleaning cloth.
Clean up all residues or foreign materials
from the two matching surfaces of cylinder
and crankcase.
Caution
To soap the residues into solvent so that
the residues can be removed more easily.

INSPECTION
Check if the inner diameter of cylinder is
worn out or damaged.
Exhaust side Intake side
In the 3 positions (top, center and bottom)
of cylinder, measure the X and Y direction
values respective in the cylinder.
Service limit: 57.7mm
Calculate both the real roundness (the Top
difference between X and Y motion values) Center
and the cylindrical roundness (the Bottom
difference in the top, center or bottom
positions of X or Y motion values.). Then,
determinate by the max. value.
Service limit
Real roundness: correct or replace as
over 0.05 mm
Cylindrical roundness: correct or replace
as over 0.05 mm

Check Cylinder flat.

Service limit: correct or replace as over
0.05 mm

7-4
SYM 7. CYLINDER/PISTON
PISTON REMOVAL
Plug crankcase opening with a cleaning cloth
to prevent from piston pin snap ring or other
parts falling into crankcase when
disassembling.
Hold another snap ring with pliers.
Push out the piston pin from the side that not
removed the snap ring.

Remove piston rings.

Caution
Pay attention to remove piston rings
because they are fragile.

Disassemble the piston rings.

Check if the piston rings are damaged or its
grooves are worn.
Cleaning the carbon in piston ring grooves.

Piston ring

Install the piston rings and then measure

clearance between piston ring and its Push in
grooves.
Service Limit: Top ring: replace if over
0.145mm
2nd ring: replace if over Piston
0.145mm Feeler gauge

Take out the piston rings and place them

respective into cylinder below 20mm of Feeler gauge
cylinder top. Measure each piston ring
gaps.
Caution
Push the piston rings into cylinder with
piston top-end in parallel motion.
piston ring
Service Limit: Top ring: replace if over
0.50mm
2nd ring: replace if over
0.750mm

7-5
7. CYLINDER/PISTON SYM
Measure the outer diameter of piston pin.
Service Limit: 14.96mm

Measure the inner diameter of connecting

rod small end.
Service Limit: 15.06mm

Measure the inner diameter of piston pin

hole.
Service Limit: 15.04mm

Calculate clearance between piston pin and

its hole.
Service Limit: 0.02mm

Measure piston outer diameter.

Caution
The measurement position is 10 mm
distance from piston bottom side, and 90°
to piston pin.

Service limit: 52.310mm

Compare measured value with service limit
to calculate the clearance between piston
and cylinder.

7-6
SYM 7. CYLINDER/PISTON
PISTON RING INSTALLATION
Clean up piston top, ring groove, and piston skirt.
Install the piston ring onto piston carefully.
Place the openings of piston ring as diagram
shown.
Caution
 Do not damage piston and piston rings as installation.
 All marks on the piston rings must be forwarded to up side.
 Make sure that all piston rings can be rotated freely after installed.

Top ring

2nd ring
120°

Side ring

Spacer Oil ring

Side ring

Over 20 mm
Top groove

2nd groove

Oil groove

7-7
7. CYLINDER/PISTON SYM
PISTON INSTALLATION
Install piston and piston pin, and place the IN
mark on the piston top side forward to intake IN mark
valve.
Install new piston pin snap ring. Piston pin
Caution

 Do not let the opening of piston pin snap

ring align with the opening piston ring.
 Place a piece of cleaning cloth between Piston
piston skirt section and crankcase in
order to prevent snap ring from falling
into crankcase as operation.

CYLINDER INSTALLATION
Clean up all residues and foreign materials
on the matching surface of crankcase.
Pay attention to not let these residues and
foreign materials fall into crankcase.
Caution
To soap the residues into solvent so that
the residues can be removed more
easily.
Install 2 lock pins and new gasket.

Coat engine oil to inside of cylinder, piston

and piston rings.
Care to be taken when installing piston into
cylinder. Press piston rings in one by one as
installation.
Caution
Do not push piston into cylinder forcefully
because this will cause the piston and the
piston rings to be damaged.

Install the cam chain plate, the cylinder head

gasket and lock pins.
Install cylinder head. (refer to Chapter 6)
Install the cam chain auto-adjuster. (2 bolts)

2 bolts

7-8
SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

MECHANISM DIAGRAM .................... 8-1 KICK STARTER ARM ........................ 8-3

MAINTENANCE DESCRIPTION ........ 8-2 DRIVING BELT .................................. 8-4
TROUBLE DIAGNOSIS ...................... 8-2 SLIDING PULLEY .............................. 8-6
LEFT CRANKCASE COVER .............. 8-3 CLUTCH/DRIVEN PULLEY ............... 8-9
MECHANISM DIAGRAM

5.5~6.0kgf-m

5.5~6.0kgf-m

1.0~1.5kgf-m

5.0~6.0kgf-m

8-1
8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

MAINTENANCE DESCRIPTION
Precautions in operation
General information
‧ Driving pulley, clutch, and driven pulley can be serviced on the motorcycle.
‧ Driving belt and driving pulley surface must be free of grease.

Specification Unit: mm
Item Standard value Limit
Driving belt width 19.50 18.50
ID of sliding pulley bush 23.989~24.052 24.060
OD of sliding pulley hub 23.960~23.974 23.940
OD of roller 15.92~16.08 15.400
ID of clutch outer 125.000~125.200 125.500
Thickness of clutch lining 3.000 2.500
Free length of driving pulley
168.900 163.700
spring
OD of driven pulley 33.965~33.985 33.940
ID of sliding pulley 34.000~34.025 34.060
ID: Inner Diameter
OD: Outer diameter

Torque value Special Service Tools

Sliding pulley nut: 5.0~6.0kgf-m Clutch spring compressor
Clutch outer nut: 5.5~6.0kgf-m Bearing puller (inner type)
driving pulley nut: 5.5~6.0kgf-m Clutch mounting nut wrench
Universal fixture

TROUBLE DIAGNOSIS
Engine can be started but motorcycle Insufficient horsepower or poor high
can not be moved speed performance
 Worn driving Belt  Worn driving belt
 Worn tilt plate  Insufficient spring capacity of driven
 Worn or damaged clutch lining pulley
 Broken driven pulley  Worn roller
 Driven pulley operation un-smoothly
Shudder or misfire when driving
 Broken clutch lining
 Worn clutch lining

8-2
SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM
air cleaner bolts
LEFT CRANKCASE COVER
Left crankcase cover removal
Remove air cleaner. (2 bolts)
Loosen vent strap on the front-left side of
cover, and then remove the vent.
Remove engine left-side cover (8 bolts).

Installation of the left crankcase

cover
Install the left crankcase cover. (8 bolts)
Install front vent tube of left cover and tighten
the strap.
Tighten the air cleaner. (2 bolts)

Left side cover plate

8 Bolts

8-3
8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM
DRIVING BELT
Removal
Remove left crankcase cover.
Hold the driving pulley with a universal fixture,
and then remove the nut and driving pulley.

Universal fixer

Hold driving pulley with universal fixture, and

remove nut and clutch outer.
Caution
Using special service tools for tightening or
loosening the nut. Fixed rear wheel or rear
brake only will damage reduction gear
system.
Nut

Universal fixer
Push the driving belt into belt groove as
diagram shown so that the belt can be
loosened, and then remove driven belt and
Driving belt
clutch at same time.

Inspection
Check the driving belt for crack or wear.
Replace it if necessary.
Measure the width of driving belt as diagram
shown. Replace the driving belt if it exceed
maintenance limited specification.
Service Limit: 18.5mm
Tooth
Caution
Width
 Using the genuine parts for
replacement.
 The surfaces of driving belt or pulley
must be free of grease.
 Clean up all grease or dirt before
installation.

8-4
SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

Installation
Pull out the driving pulley and then insert the
driving belt into the driving pulley.
Sliding
driven
Caution pulley

Pull out driving pulley and then insert the

driving belt into the driving pulley so that the
driving belt set can be installed onto sliding
pulley more easily.

Sliding pulley Belt Clutch outer

Install the clutch set with driving belt onto the
driving shaft.
Install the sliding pulley on the other end of
belt.
Install clutch outer.

Clutch outer
Install the clutch with universal fixture, and
then tighten nut to specified torque value.
Torque value: 5.5~6.0 kgf-m
Nut

Universal fixer

Caution
When install the driving belt, if there is a
arrow mark, then the arrow mark must
point to rotation motion. If not, the letters
on the belt must be forwarded to
assembly direction.

8-5
8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM
SLIDING PULLEY
REMOVAL
Remove left crankcase cover.
Hold driving pulley with universal fixture, and
then remove driving pulley nut.
Remove driving pulley.

Universal fixture

Remove the driving belt from the pulley. Sliding pulley

Remove sliding pulley set and driving pulley
hub from crankshaft.

Crankshaft
Driving pulley hub

Remove tilt plate.

Tilt plate

Remove weight rollers from sliding pulley. Sliding pulley

Roller

8-6
SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

Inspection
The operation of sliding pulley is means of Weight roller
the weight roller to pressing on it with
centrifuge force. And then the speed is
changed by the title plate rotation. Thus, if
weight rollers are wear out or damage, the
centrifuge force will be effected.
Check if rollers are wear out or damage.
Replace it if necessary.
Measure each rollers’ outer diameter.
Replace it if exceed the service limit.
Service limit: 15.40 mm

Check the pulley hub if damaged or wear out. Sliding pulley

Replace it if necessary.
Measure the pulley hub’s outer diameter.
Replace it if exceed the service limit.
Pulley hub
Service limit: 23.94 mm

Measure the inner diameter of the pulley

bush.
Replace it if exceed the service limit.
Service limit: 24.06 mm

Weight roller
Assembly/Installation
Install the weight rollers.

Install the title plate guide boot onto the title Guide boot
plate.
Install the title plate.

Tilt plate

8-7
8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

Apply with grease 4~5 g to inside of driving

shaft hole, and install driving pulley hub.

Caution
The pulley surface has to be free of grease.
Clean it with cleaning solvent.

Pulley surface

Install siding pulley assembly onto crankshaft. Sliding pulley

Crankshaft Pulley hub

Driving pulley install Press down

Press driving belt into pulley groove, and
then press down the up & down sides of the
driving belt to separate it away from the
driving pulley hub.
Caution
To press down the up & down sides of
the driving belt can avoid to pressing and
damaging the belt when installing the Driving belt
driving pulley, and also can make sure
that the driving pulley can be tighten.

Install driving pulley, washer and nut.

Caution
Make sure that two sides of pulley surfaces
have to be free of grease. Clean it with
cleaning solvent.
Hold driving pulley with universal fixture.
Tighten nut to specified torque.
Torque value: 5.0~6.0 kgf-m
Universal fixture
Install left crankcase cover.

8-8
SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM
CLUTCH/DRIVEN PULLEY Special nut wrench
Disassembly
Remove driving belt and clutch/driven pulley.
Install clutch spring compressor onto the
pulley assembly, and operate the
compressor to let nut be installed more
easily.

Caution
Do not press the compressor too much.
Clutch spring compressor

Hold the clutch spring compressor onto

bench vise, and then remove mounting nut
with special nut wrench.
Release the clutch spring compressor and
remove clutch and spring from driven pulley.
Remove socket from driven pulley.

Socket

Sliding pulley
Remove oil seal from driven pulley. Oil seal Guide pin
Remove guide pin, guide pin roller, and
sliding pulley, and then remove O-ring & oil
seal seat from sliding pulley.

Guide pin
O-ring Guide pin roller

Inspection
Clutch outer
Measure the inner diameter of clutch outer
friction face. Replace the clutch outer if
exceed service limit.
Service limit: 125.5 mm Inner
diameter Clutch outer

8-9
8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

Clutch lining Clutch lining

Measure each clutch lining thickness.
Replace it if exceeds service limit.
Service limit: 2.5mm

Clutch

Driven pulley spring

Measure the length of driven pulley spring.
Replace it if exceeds service limit.
Service limit: 163.7mm

Free length

Driven pulley Outer diameter

Check following items;
‧ If both surfaces are damage or wear. Inner diameter
‧ If guide pin groove is damage or wear. Driven face
Replace damaged or worn components.
Measure the outer diameter of driven face
and the inner diameter of movable driven
face. Replace it if exceeds service limit.
Service limit: Outer diameter 33.94mm
Inner diameter 34.06mm
Driven surface Movable
Guide pin groove
driven face

Driven Pulley Bearing Inspection

Check if the inner bearing oil seal is damage.
Replace it if necessary.
Check if needle bearing is damage or too big
clearance. Replace it if necessary.
Rotate the inside of inner bearing with
fingers to check if the bearing rotation is in Needle bearing
smooth and silent.

Outer ball bearing

8-10
SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

Clutch Block Replacement

Driving plate
Remove snap and washer, and the remove Spring
clutch block and spring from driving plate.
Check if spring is damage or insufficient
elasticity.

Snap ring

Clutch block

Check if shock absorption rubber is damage Shock absorption rubber

or deformation. Replace it if necessary.
Apply with grease onto setting pins.

Setting pin

Apply with grease onto setting pins. But, Shock absorption rubber
the clutch block should not be greased. If so,
replace it.
Install new clutch block onto setting pin and
then push to specified location.
Caution
 Grease or lubricant will damage the
clutch block and effect the block’s
connection capacity.
Clutch block

Install the spring snap into groove with pliers.

Spring

8-11
8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

Install snap ring and mounting plate onto

setting pin.

Snap ring

Replacement of driven pulley bearing

Remove inner bearing. Oil seal
Caution Outer bearing

 If the inner bearing equipped with oil seal

on one side in the driven pulley, then
remove the oil seal firstly.
 If the pulley equipped with ball bearing, it
has to remove snap ring and then the
bearing.
Snap ring Inner needle
bearing

Remove snap ring and then push bearing

forward to other side of inner bearing. Specified grease
Place new bearing onto proper position and
its sealing end should be forwarded to
outside. Snap ring
Apply with specified grease.
Recommended to use the KING MATE G-3.
Install the snap ring and hold the bearing.
Outer bearing

Sealing end

Install a new inner bearing. Sealing end

Caution
 Its sealing end should be forwarded to
outside as bearing installation.
 Install needle bearing with hydraulic
presser. Install ball bearing by means of
hydraulic presser.
Inner bearing
Align oil seal lip with bearing, and then install
the new oil seal (if necessary).

8-12
SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

Installation of clutch/driven pulley Oil seal

Install new oil seal and O-ring onto sliding
pulley. Apply with specified grease to
lubricate the inside of sliding pulley.

Specified
O-ring grease

Install sliding pulley onto driven pulley. Sliding pulley Guide pin
Oil seal
Install guide pin and guide pin roller.

Guide pin
O-ring Guide pin roller

Install oil socket. Oil socket

Install driven pulley, spring and clutch into Special nut wrench
clutch spring compressor, and press down
the assembly by turning manual lever until
mounting nut that can be installed.
Hold the compressor by bench vise and
tighten the mounting nut to specified torque
with special nut wrench.
Remove the clutch spring compressor.
Torque value: 5.5~6.0 kg-m
Install clutch/driven pulley and driving belt
onto driving shaft. Clutch spring compressor

8-13
SYM 9. FINAL DRIVING MECHANISM

MECHANISM DIAGRAM .................... 9-1 INSPECTION OF FINAL DRIVING

OPERATIONAL PRECAUTIONS ....... 9-2 MECHANISM ..................................... 9-3
TROUBLE DIAGNOSIS ...................... 9-2 BEARING REPLACEMENT ............... 9-4
DISASSEMBLY OF FINAL DRIVING RE-ASSEMBLY OF FINAL DRIVING
MECHANISM ...................................... 9-3 MECHANISM ..................................... 9-6
MECHANISM DIAGRAM

Countershaft
Final driving shaft

Final driving gear

Countershaft gear

Driving gear

0.8~1.2 kgf-m

2.0~2.4 kgf-m

9-1
9. FINAL DRIVING MECHANISM SYM
OPERATIONAL PRECAUTIONS
Specification Torque value
Application gear oil: 4-stroke lubricant Gear box cover 0.8~1.2 kgf-m
Recommended gear oil:85W-140 Gear oil drain plug 1.0~1.4 kgf-m
Oil quantity: 180 c.c. (170 c.c. when Gear oil filling bolt 0.8~1.2 kgf-m
replacing)

Tools
Special service tools
Inner type bearing puller
Outer type bearing puller
Gear box oil seal installer
Gear box bearing installer

TROUBLE DIAGNOSIS
Engine can be started but motorcycle Gear oil leaks
can not be moved  Excessive gear oil
 Damaged driving gear  Worn or damage oil seal
 Burnt out driving gear
 Broken driving belt

Noise
 Worn or burnt gear
 Worn gear

9-2
SYM 9. FINAL DRIVING MECHANISM
DISASSEMBLY OF FINAL DRIVING
MECHANISM
Remove the rear wheel. (refer to chapter 15)
Remove the clutch.
Drain gear oil out from gear box.
Remove gear box cover bolts (7bolts) and
then remove the cover and the final driving
shaft.
Remove gasket and setting pin.

7 bolts

final driving shaft

Remove countershaft and gear.
Remove final driving gear and shaft. final driving gear
countershaft gear

countershaft

driving shaft

INSPECTION OF FINAL DRIVING

MECHANISM
Check if the countershaft and the gear are
wear or damage.

Check if the final driving shaft and gear are

burn, wear or damage.

Final drive shaft

9-3
9. FINAL DRIVING MECHANISM SYM

Check bearings on gear box and cover. Final driving

Rotate each bearing’s inner ring with fingers. shaft
Final driving gear
Check if bearings can be turned in smooth Countershaft gear
and silent, and also check if bearing outer
ring is mounted on gear box & cover tightly.
If bearing rotation is uneven, noising, or
loose bearing mounted, then replace it.
Check oil seal for wear or damage, and Countershaft
replace it if necessary. Bearing
Caution Oil seal
Driving shaft
 Do not remove the driving shaft from
the cover top side.
 If remove the driving shaft from the
cover top side, then its bearing has to
be replaced.
Check driving shaft and gear for wear or
damage.

BEARING REPLACEMENT
Caution
Never install used bearings. Once bearing
removed, it has to be replaced with new
one.

Remove driving shaft bearing from left

crankcase using following tools;
Inner type bearing puller

Install new driving shaft bearing into left

crankcase.
Tool:
Press the bearing into cover with C type
hydraulic presser or bearing installer.

9-4
SYM 9. FINAL DRIVING MECHANISM
Press out the driving shaft from the
crankcase.
Remove oil seal from the gear box.
Remove the driving shaft bearing from the
gear box cover with the inner type bearing
puller.
Caution
Using the bearing protector as pressing out
the driving shaft from the left crankcase.

Driving shaft
Specified tool:
Inner type bearing puller.
Bearing protector

If the driving shaft is pulled out with its

bearing, then remove the bearing with bearing
puller and bearing protector.
Tool:
Multi-functional bearing puller
Bearing protector

Multi-functional bearing puller

Install a new driving shaft bearing onto

crankcase.
Then, install the driving shaft.
Specified tool:
Press the bearing in with C type hydraulic
presser or bearing installer.

Driving shaft

Install a new final driving shaft bearing onto

gear box cover.
Specified tool:
Press the bearing in with C type hydraulic
presser or the bearing installer.
Apply with some grease onto the lip section
of oil seal and then install the seal.

9-5
9. FINAL DRIVING MECHANISM SYM
RE-ASSEMBLY OF FINAL DRIVING Countershaft
Final shaft
MECHANISM
Install final shaft and final shaft driven gear,
countershaft.

Final shaft driven gear

Install the setting pins(2 pins) and new gasket. Dowel pins

Gasket

Apply with grease onto the oil seal lip of final

driving shaft.
Install the gear box cover and 7 bolts.
(tighten the bolts)
Torque: 0.8~1.2 kgf-m
Install the clutch/sliding driving pulley.
Install the driving pulley, belt and left
crankshaft cover.
Install the rear wheel.
Add gear oil.
Recommended usage: SAE 85W-140
(180 cc: standard capacity)
(170 cc: when replacement)

7 bolts

9-6
SYM 10. A.C. GENERATOR/STARTING CLUTCH

MECHANISM DIAGRAM .................... 10-1 RIGHT CRANKCASE COVER

PRECAUTIONS IN OPERATION ....... 10-2 INSTALLATION .................................. 10-8
A.C.GENERATOR REMOVAL ........... 10-3 MOUNTED COIL SET
RIGHT CRANKCASE COVER INSTALLATION .................................. 10-8
REMOVAL .......................................... 10-4 FLY WHEEL INSTALLATION ............. 10-8
STARTING CLUTCH .......................... 10-5
MECHANISM DIAGRAM

5.0~6.0kgf-m

9.0~10.0kgf-m

1.0~1.4kgf-m

1.5~2.0kgf-m

1.3~1.7kgf-m

10-1
10. A.C. GENERATOR/STARTING CLUTCH SYM
PRECAUTIONS IN OPERATION
General information
 Refer to chapter 5: Engine removal and installation
 Refer to chapter 1: The troubleshooting and inspection of A.C. generator
 Refer to chapter 16: The service procedures and precaution items of starter motor

Specification Unit: mm
Item Standard value Service Limit

ID of starting driven gear 32.0 32.060

OD of starting clutch cover 28.0 27.940

Torque value:
Flywheel nut 5.0~6.0kgf-m
Exhaust muffler bolt 8 mm 1.5~2.0kgf-m
Oil screen cover 1.3~1.7kgf-m
Starting clutch hex lock nut 9.0~10.0kgf-m with oil on the thread
Starting clutch hex socket bolt 1.0~1.4kgf-m with adhesive

Special service tools

Flywheel puller
Universal fixture

10-2
 SYM 10. A.C. GENERATOR/STARTING CLUTCH
A.C. GENERATOR REMOVAL
Pulse generator
Coil
Flywheel

Cooling fan
shroud

Cooling fan

Drain out the engine oil.

Remove the body cover. Exhaust muffler
Remove the exhaust muffler. (2 bolts, 2 nuts)
Remove the fan shroud. (4 bolts)

Cooling fan shroud

Remove the fan. (4 bolts)

Cooling fan

Hold the flywheel with the universal fixture.

Remove the 10mm nut on the flywheel.
Universal fixture
Special Service Tools:
Universal Fixture

10-3
10. A.C. GENERATOR/STARTING CLUTCH SYM
Remove the flywheel with the flywheel puller.
Special service tools:
Flywheel puller
Shaft protector
Caution
Install a shaft protector on the right end of
crankshaft to avoid damaging the crankshaft
before installing the flywheel puller.

Flywheel puller

Remove the connectors of the A.C.

generator and pulse generator.

Remove the 6 bolts for the pulse generator,

the A.C. generator coil and cable guide.
Then, remove the A.C. generator assembly.
Caution
Do not damage the alternator coil.

6 bolts
RIGHT CRANKCASE COVER
REMOVAL
Remove the right crankcase cover. (6 bolts)
Remove setting pin and gasket.
Remove the gasket or foreign materials on
the connection surfaces of both the cover
and crankcase.
Caution
Do not damage the connection surfaces.

10-4
SYM 10. A.C. GENERATOR/STARTING CLUTCH
STARTING CLUTCH
Starting Clutch Removal
Hold the starting driven gear with the
universal fixture.
Remove the 22mm anti-loosen lock nut and Lock nut
gasket.
Special service tools:
Anti-loosen lock nut socket
Universal fixture.
Caution
The mounting nut is left-turn thread. Lock nut socket

Remove the starting driven gear. Starting driven gear

Shaft
Remove starting clutch, starting reduction
gear, and shaft.

Starting reduction gear

Starting driven gear

Starting Clutch Inspection
Install the starting clutch onto the starting
driven gear.
Hold the starting clutch and turn the starting
driven gear.
The starting driven gear should can be
turned in the motion of C.W. and can not be
turned in C.C.W.

10-5
10. A.C. GENERATOR/STARTING CLUTCH SYM
Check the starting driven gear for wear or Starting driven gear
damage.
Measure the ID of the starting driven gear.
Service Limit:
ID: 32.06 mm or less

Starting reduction
Check the starting reduction gear and shaft gear
for wear or damage.
Measure the ID of the starting reduction
gear.
Service Limit:
ID: 10.05 mm or less

Measure the OD of the starting reduction

gear shaft.
Service Limit:
OD: 9.94 mm or above

Hex blots
Disassembly Plug Spring
Remove the hex blots (3 bolts) inside the
starting clutch.
Separate the clutch body and the clutch
cover. Roller
Remove the rollers, plugs, and springs on
the one way clutch.
Check each rollers and plugs for wear or
damage.
Install rollers, plugs and springs. Clutch cover

Measure the OD of the starting clutch cover.

Service Limit:
OD: 27.94 mm or above

Starting clutch
cover

10-6
SYM 10. A.C. GENERATOR/STARTING CLUTCH
Installation Hex socket
Install the components in the reverse bolt
procedures of removal. Plug Spring

Caution
Add adhesive onto the thread of hex
Roller
socket bolt.
Torque value: 1.0~1.4kgf-m
Clutch body

Clutch cover

Starting clutch Installation Shaft

Install reduction gear shaft and reduction gear.

Install starting clutch.

Starting reduction gear

Install the starting clutch outer and starter

driven gear.

Starter driven gear

Hold the starting driven gear with the

universal fixture.
Tighten the 22mm anti-loosen lock nut and
gasket.
Caution Lock nut
Add engine oil onto the thread of lock nut.

Special service tools:

Anti-loosen lock nut socket
Universal fixture
Torque value: 9.0~10.0kgf-m Lock nut socket

10-7
10. A.C. GENERATOR/STARTING CLUTCH SYM
RIGHT CRANKCASE COVER 6 bolts
INSTALLATION
Install setting pin and new gasket on the
crankcase.
Replace the right crankshaft oil seal of the
crankcase and apply some oil onto the oil
seal lip.
Install right crankcase cover onto the right
crankcase. (8 bolts)
Torque value: 1.5~2.0kgf-m

MOUNTED COIL SET

INSTALLATION
Install the coil set onto right crankcase
cover. (2 screws)
Install pulse generator. (2 screws)
Tighten the cable guide. (2 screws)
Torque: 1.5~2.0kgf-m
Tie the wire harness hose onto the indent of
crankcase.
Caution
Make sure that the wire harness is placed
under the pulse generator.

Install A.C. generator connector and pulse

generator connector.

10-8
SYM 10. A.C. GENERATOR/STARTING CLUTCH

FLYWHEEL INSTALLATION
Make sure that there is no magnetic powder. Universal fixture

If so, clean up it.

Align insert on crankshaft with the flywheel
groove, and then install the flywheel.
Hold the flywheel with flywheel holder, and
tighten its nut.
Torque value: 5.0~6.0kgf-m
Special service tool:
Universal fixture

Check the clearance between the sensor

and flywheel
Clearance: 0.7~0.9mm

Install the cooling fan. (4 bolts)

Torque value: 0.8~1.2kgf-m

Cooling fan

Install the cooling fan shroud. (4 bolts) Exhaust muffler

Install the exhaust muffler. (2 bolts, 2 nuts)
Install the body cover.
Add some engine oil according the
specified quantity.

10-9
Cooling fan shroud
SYM 11. CRANKCASE/CRANKSHAFT

MECHANISM DIAGRAM .............. 11-1 DISASSEMBLY OF CRANKCASE 11-3

OPERATIONAL PRECAUTIONS ... 11-2 CRANKSHAFT INSPECTION ....... 11-5
TROUBLE DIAGNOSIS ............... 11-2 ASSEMBLY OF CRANKCASE ..... 11-6
MECHANISM DIAGRAM

1.5~2.0 kgf-m

1.0~1.4 kgf-m

0.7~1.0 kgf-m
0.8~1.2 kgf-m

0.8~1.2 kgf-m

3.5~4.5 kgf-m

11-1
11. CRANKCASE/CRANKSHAFT SYM
OPERATIONAL PRECAUTIONS
General Information
 This Section contains descriptions concerning disassembly of the crankcase so that the
crankshaft can be serviced.
 Complete following operations before disassembling crankcase.
Engine Chapter 5
Cylinder head Chapter 6
Cylinder and piston Chapter 7
V-belt Drive pulley Chapter 8
AC generator/ Starting Clutch Chapter 10
Start motor Chapter 16
 If the crankshaft bearing or timing sprocket need be replaced, then the crankshaft set
have to replaced.

Specification Unit: mm
Item Standard Limit
Left, right clearance of the big end
0.100~0.350 0.550
of the connecting rod
Radial clearance of the big end of
0.000~0.008 0.050
the connecting rod
Left side: Below 0.035 Left side: 0.035
Run-out
Right side: Below 0.035 Right side: 0.030

Torque value
Bolts for crankcase 1.5~2.0 kgf-m
Bolts for cylinder/cylinder head 0.7~1.0 kgf-m
Engine oil draining plug 3.5~4.5 kgf-m
Bolts for cam chain tensioner 0.8~1.2 kgf-m

Special Service Tools

Crankcase remover/set
Crankshaft installation puller
Inner type bearing puller
Outer type bearing puller
Bearing pressing tools
Oil seal pressing tools

TROUBLE DIAGNOSIS
Engine noise
 Loose crankshaft bearing
 Loose crankshaft pin bearing
 Wear piston pin or piston pin hole

11-2
SYM 11. CRANKCASE/CRANKSHAFT
DISASSEMBLY OF CRANKCASE 2 bolts
Remove the 2 bolts from the right crankcase.

Remove the cam chain tensioner (hex socket 1 hex socket bolt
bolt) from the left side of crankcase.

Place the left side of crankcase upward,

and then install the crankcase remover/set
onto the crankcase.
Drive the screw of the crankcase
remover/set into the crankcase, and then
separate the left and the right crankcases.
Remove the cam chain.
Caution
 Never pry out the connection surfaces
of crankcases as separating.
Otherwise, the connection surfaces
could be damaged and cause oil
leaking.
 It have to separate the cam chain and
the drive gear before pressing out the
both left and right crankcases.
Special Service Tools:
Crankcase remover/set

11-3
11. CRANKCASE/CRANKSHAFT SYM
Remove the crankshaft from the right
crankcase.
Caution
 The left and right bearings of crankshaft is
to press-fit onto the crankshaft.

Remove gasket and dowel pins (2).

Scrape gasket residues off the crankcase
contact surface.
Caution
 Do not damage contact surface of the
crankcase.
 Soap the gasket residues into solvent
and the residues will be removed
easily.

Remove oil seal from the left crankcase.

11-4
SYM 11. CRANKCASE/CRANKSHAFT
CRANKSHAFT INSPECTION
Measure left and right clearance of connecting
rod big end.
Service limit: Replace when it is more
than 0.55 mm

Measure the radical clearance of the big

end at the vertical directions.
Service limit : 0.05 mm

Place the crankshaft onto a V-block and

measure run-out of the crankshaft with dial
gauge.
Service limit: Left side: 0.035mm
Right side: 0.030mm

60 mm 90 mm

Bearing Inspection clearance

Rotate the bearing with fingers and make
sure the bearing can be rotated smoothly clearance
and quietly.
Check if the inner ring is connected onto the
crankshaft tightly.
Replace crankshaft as a set when noise or
looseness is detected.

11-5
11. CRANKCASE/CRANKSHAFT SYM
ASSEMBLY OF CRANKCASE
Install cam chain into the chain hole of the
left crankcase, and then split out the cam
chain.
Caution
 Do not damage the cam chain as
installing the crankshaft.

Install crankshaft into the left crankcase and

then install two dowel pins and new dowel pins
crankcase gasket.

Install the right crankcase and tighten the 2 bolts

crankcase bolts (2 bolts).
Torque value: 1.5~2.0 kgf-m

Install the cam chain tensioner. hex socket bolt

Install a new O-ring onto the mounting bolt
of the chain tensioner.
Apply some oil on the O-ring and tighten the
bolt.
Torque value: 0.8~1.2 kgf-m
Caution
 The O-ring must be installed into the
bolt’s groove.

11-6
SYM 11. CRANKCASE/CRANKSHAFT
Apply with some grease onto the oil seal lip
and then install it onto the left crankcase.

Press-fit the oil seal to specified position

with the oil seal installer (19.8x30x5).
Special service tools: the oil seal
installer (19.8x30x5)

11-7
 SYM 12. BODY COVER
1
MAINTENANCE INFORMATION........ 12-2 FRONT CENTER COVER .................. 12-8
HANDLE COVER ............................... 12-3 LUGGAGE BOX ................................. 12-8
FRONT COVER.................................. 12-4 FLOOR PANEL .................................. 12-8
FRONT INNER BOX........................... 12-5 SIDE COVER ..................................... 12-9
BODY COVER/REAR CENTER UNDER COVER ................................. 12-10
COVER/REAR FENDER .................... 12-6
meter panel
wind screen garnish
handle down cover A

L. Body cover handle down cover B meter visor

L. Body lower cover inner box

RR center cover inner box lid wind screen

center cover LH. FR. cover

RR fender

RR carrier R. Body cover

head light low cover

R. Body lower cover

FR. under cover RH. FR. cover

RH. FR. side cover
seat
RH. RR. side cover

battery cover
under cover
luaggue box Floor panel FR fender

LH. RR. side cover

LH. FR. side cover

12-1
12. BODY COVER SYM
MAINTENANCE INFORMATION
Body covers disassemble sequence:

 Be careful not to damage various covers in disassembly or re-assembly operation.

 Never injure hooks molded on the body covers in disassembly or re-assembly operation.
 Align the buckles on the guards with slot on the covers.
 Make sure that each hook is properly installed during the assembly.
 Never compact forcefully or hammer the guard and the covers during assembly.

12-2
SYM 12. BODY COVER
FRONT COVER
Removal wind screen garnish:
Remove 2 lower mounting screw of the
head light low cover.

screws×2

Remove the mounting screws to

disassembly the wind screen garnish set

screws

Remove the 2 mounting screws to

disassembly the wind screen garnish set

screws×2

Disassembly the wind screen garnish

Installation:
Install according to the reverse procedure
of removal.

12-3
12. BODY COVER SYM
FRONT COVER
Removal meter visor
Remove the 3 mounting screws between the
right meter visor.

screwsx3

Remove the 3 mounting screws between the

left meter visor.

screwsx3

Disassembly the meter visor

Installation:
Install according to the reverse procedure
of removal.

12-4
SYM 12. BODY COVER
FRONT COVER

Removal wind screen

Remove the 9 mounting screws between the
wind screen.

screwsx9

Disassembly the wind screen

Installation:
Install according to the reverse procedure
of removal.

Removal Front Cover

Remove the mounting screw of left front side
cover

screw

Remove the mounting screw of right front

side cover

screw
12-5
12. BODY COVER SYM

Remove the 4 mounting screws of left front screws x 4

cover

screws x 4
Remove the 4 mounting screws of right front
cover

screws x 3
Remove the 3 mounting screws of inner box
left upper side

screws x 3
Remove the 3 mounting screws of inner box
left under side

12-6
SYM 12. BODY COVER

screws x 3
Remove the 3 mounting screws of inner box
right upper side

Remove the 3 mounting screws of inner box screws x 3

right under side

Push up the hook.

Remove the mounting bolt of inner cover

bolt

12-7
12. BODY COVER SYM

Remove the 2 mounting nuts of meter panel

nuts x 2

Remove the speed cable connecting

Remove the winker light connecting

Remove the head light connecting

12-8
SYM 12. BODY COVER

Disassembly the front cover

Installation:
Install according to the reverse procedure
of removal.

Disassembly the meter, remove the 4 screws

of the meter panel

Installation:
Install according to the reverse procedure
of removal.

screws x 4

12-9
12. BODY COVER SYM
BODY COVER

Remove the 4 mounting bolts of luggage box

bolts x 4

Be careful the engine stop switch connecting

socket bolts x 3
Remove the 3 mounting socket bolts of rear
carrier

Remove the 2 mounting bolts of rear fender

bolts x 2

12-10
SYM 12. BODY COVER

Remove the mounting screw between

the right body cover and floor panel.

screw x 1

Remove the mounting screw between

the left body cover and floor panel.

screw x 1

Remove the 2 mounting screws of center cover.

screws x 2

screws x6
Remove the 6 mounting screws of battery
cover.

Installation:
Install according to the reverse procedure
of removal.

12-11
SYM 13. BRAKE
MECHANISM DIAGRAM-FRONT BRAKE FLUID
DISC BRAKE SYSTEM ...................... 13-1 REPLACEMENT/AIR-BLEED ............ 13-6
MECHANISM DIAGRAM-REAR BRAKE CALIPER .............................. 13-7
DRUM BRAKE SYSTEM .................... 13-2 BRAKE DISC ..................................... 13-8
MAINTENANCE INFORMATION ....... 13-3 BRAKE MASTER CYLINDER............ 13-8
TROUBLE DIAGNOSIS ..................... 13-4 DRUM BRAKE-DRUM ....................... 13-11
HYDRAULIC BRAKE SYSTEM BRAKE LING ..................................... 13-11
INSPECTION ...................................... 13-5 BRAKE PANEL .................................. 13-12
MECHANISM DIAGRAM
Front Disc Brake System

3.3~3.7 kgf-m

4.0~4.5 kgf-m

13-1
13. BRAKE SYM

MECHANISM DIAGRAM
Rear Disc Brake System

3.3~3.7 kgf-m

4.0~4.5 kgf-m

13-2
SYM 13. BRAKE

MAINTENANCE INFORMATION
Precautions in Operation
Caution
Installing lining dusts may cause disorders of respiration system or cancer, therefore, never
use air hose or dry brush to clean brake parts. Use vacuum cleaner or other authorized tool
instead.

 The brake caliper can be removed without removing the hydraulic system.
 After the hydraulic system is removed, or the brake system is felt to be too soft, bleed the
hydraulic system.
 While refilling brake fluid, care should be taken not to let the foreign material entering
into the brake system.
 Do not spill brake fluid on the painted surfaces, plastic or rubber parts to avoid damage.
 Check the operation of the brake system before you go.

Specifications Unit: mm
Item Standard Limit
The thickness of front brake disc 3.50 2.00
The thickness of rear brake disc 3.50 2.00
Front brake disc eccentricity 0.15 0.30
Rear brake disc eccentricity 0.15 0.30
Master cylinder inner diameter 25.40 ─

OD of front brake disc 260.00 ─

OD of rear brake disc 240.00 ─
Thickness of front disc brake lining ─ As brake ling mark

Thickness of rear brake lining ─ 2mm or As brake ling mark

Torque values
Bolt for front brake lever 0.8~1.2kgf-m
Bolt for rear brake lever 0.8~1.2kgf-m
Brake hose bolt 3.3~3.7kgf-m
Bolt for brake caliper 3.1~3.5kgf-m
Air-bleed valve 0.8~1.0kgf-m

13-3
13. BRAKE SYM

TROUBLE DIOGNOSIS
DISC BRAKE
Soft brake lever Uneven brake
 Air inside the hydraulic system  Dirty brake lining/disc
 Hydraulic system leaking  Poor wheel alignment
 Worn master piston  Clogged brake hose
 Worn brake pad  Deformed or warped brake disc
 Poor brake caliper  Restricted brake hose and fittings
 Worn brake lining/disc
 Low brake fluid Tight brake
 Blocked brake pipe  Dirty brake lining/disc
 Warp/bent brake disc  Poor wheel alignment
 Bent brake lever  Deformed or warped brake disc

Hard operation of brake lever Brake noise

 Blocked brake system  Dirty lining
 Poor brake caliper  Deformed brake disc
 Blocked brake pipe  Poor brake caliper installation
 Seized/worn master cylinder piston  Imbalance brake disc or wheel
 Bent brake lever

13-4
SYM 13. BRAKE

HYDRAULIC BRAKE SYSTEM Hose connection

INSPECTION
Inspection
Visual inspect for brake fluid leaking or
damage. Check if brake hose connection
loosen with wrench and turn the handlebar
from right to left motion or press down the
shock absorber to check if there is something
is interfered with the brake system or brake
components.

brake lining
Operate the brake system and check the wear limitation
brake lining. Check the front brake from groove
front side, and replace the brake lining with
new one when the brake lining wear limitation
groove reaches to the brake disc.

brake caliper Brake disc

Park the motorcycle on a flat ground and
check its brake fluid level.
Recommended brake fluid: WELLRUN DOT 3
brake fluid
CAUTION
lower level
 The fluid level will not be correct if
parking the motorcycle in title or just
parking. It has to waiting for around
3~5 minutes.
 Never use faked brake fluid to prevent
from chemical reaction.
 It has to apply with same brand brake
fluid to sure the brake performance.
Brake Fluid Add Master
Turn the handlebar to let the master cylinder cylinder cap
in horizontal position before removed the
master cylinder cap.
Place a rag onto painting, plastic or rubber
components when conduct brake system
maintenance.
CAUTION
 Do not over the upper level when adding
brake fluid and avoid to spilling brake fluid
on painted surfaces, plastic or rubber
components to result in their damages.

13-5
13. BRAKE SYM
Remove the master cylinder cap and
diaphragm. master
Add good quality brake fluid and it has to add cylinder
same brand brake fluid into the master cylinder.
Clean dirty brake disc. diaphragm
CAUTION
The dirty brake lining or disc will reduce the
brake performance. The mixed
non-compatible brake fluid will reduce brake
performance. Foreign materials will block
the system causing brake performance to
be reduced or totally lost.
BRAKE FLUID REPLACEMENT/
AIR-BLEED drain valve
Connect drain hose to drain valve.
Open the drain valve on the caliper and hold
and release the brake lever alternatively until
the old brake fluid is entirely drained out.
Close the drain valve and add specified
brake fluid into the brake master cylinder.
CAUTION
To reuse the spent brake fluid will effect
brake performance.
Connect one end of transparent hose to the
drain valve, and put the other end into a
container.
Open the drain valve around 1/4 turns, and
at the same time hold the brake lever until
the there is no air bubble in the drain hose Bubbles
and also feeling resistance on the brake
lever.
Close the drain valve when finishing the
brake system refilling fluid procedure, and
operate the brake lever to check whether air
bubble is in brake system or not. If brake is
still soft, please bleed the system as
described below. Drain valve
1. Tightly hold the brake lever and open the
drain valve around 1/4 turns, and then close
the valve.
CAUTION Transparent hose
 Do not release the brake lever before the
drain valve is closed.
 Always check the brake fluid level when
carrying out the air bleeding procedure to
avoid air entering into the system.
2. Slowly release the brake lever, and wait for
a few seconds until it reaches its top
position.
3. Repeat the steps 1 and 2 until there is no air
bubble at the end of the hose. Tightly close
the drain valve.
4. Make sure the brake fluid is in the UPPER
level of the master cylinder, and refill the
fluid if necessary.
5. Cover the cap.

13-6
SYM 13. BRAKE

BRAKE CALIPER Caliper bolts x2

Removal
Place a container under the brake caliper,
and loosen the brake hose bolt and finally
remove the brake hoses.
CAUTION
 Do not spill brake fluid on painted
surfaces.
Remove two caliper bolts and the caliper.

Make sure the brake lining condition. Replace

the lining if the brake lining wear limitation brake pad wear
groove close to the brake disc. limitation groove
Brake Lining Replacement
Compress the caliper and let the brake lining
out of the caliper mounting plate. Compress the
brake lining locking spring. Remove the inner
brake lining firstly and then remove the outer
brake lining.
Compress the brake caliper at first as
installation. Install the inner brake lining firstly,
and then install the outer brake lining.
brake pad

brake mounting
INSTALLATION brake lining plate
Install the brake caliper and tighten the
attaching bolts securely.
Torque: 3.3 kgf-m
CAUTION piston
 Use M8 x 35 mm flange bolt only.
 Long bolt will impair the operation of
brake disc. brake
caliper
Tighten the lining guide bolt. locking spring
Torque: 1.8 kgf-m

Use two seal washers and hose bolts to lock

the hose and brake caliper in place.
Torque: 3.5 kgf-m

Refill up the brake fluid to the reservoir and

make necessary air bleeding.

13-7
 To this chapter contents

13. BRAKE SYM

Rear Brake Caliper Brake hose bolts

Removal
Place a container under the brake caliper, and
loosen the brake hose bolt and finally remove
the brake hose.
Caution
 Do not spill brake fluid on painted surfaces.
Remove two caliper mounting bolts and the
caliper.
Installation Caliper mounting bolts
Install the brake caliper and tighten the
mounting bolts.
Torque: 2.9~3.5kgf-m
Caution
 Use M8 x 35 mm flange bolt only.
 Long bolt will impair the operation of
brake disk.
Use two seal washers and hose bolts to lock
the hoses and brake caliper in place.
Torque: 3.0~4.0kgf-m
Refill up the brake fluid to the reservoir and
Socket bolts
make necessary air bleeding.

Brake pad replacement

Remove the brake caliper upper parts (2 socket
bolts).

Take out the brake pads.

Install the new brake pads onto brake caliper

bracket.
Install the brake caliper upper parts and
tighten the socket bolts.

13-8
SYM 13. BRAKE

BRAKE DISC
Inspection
Visually check the brake disc for wear or
break.
Measure the thickness of the disc at several
places. Replace the disc if it has
exceeded the service limit.
Allowable limit: 2.0 mm brake disc
micrometer

Remove the brake disc from wheel.

Check the disc for deformation and bend.
Allowable limit: 0.30 mm
CAUTION
 Do not let grease touch to the brake disc
that will cause brake performance.
 Do not clean the brake lining with air gun.
Operator should wear mask & glove and
use vacuum cleaner to clean the brake
lining.

BRAKE MASTER CYLINDER

Removal
brake hose
CAUTION
Do not let foreign materials enter into the
cylinder.

CAUTION bolts x2
The whole set of master cylinder, piston,
spring, diaphragm and circlip should be
replaced after removal.
Remove the front and rear handlebar
guards. circlip
rubber boot
Remove the leads of brake lamp switch.
Drain out the brake fluid. brake lamp
piston switch
Remove the brake lever from the brake
master cylinder. rubber spring
Remove the brake hose. washer
Remove the master cylinder seat and the
master cylinder. master
Remove the rubber pad. cylinder
Remove the circlip.
Remove the piston and the spring.
Clean the master cylinder with
recommended brake fluid.

13-9
13. BRAKE SYM

Inspection
Check the master cylinder for damage or master cylinder
scratch. Replace it if necessary.
Measure the cylinder inner diameter at
several points along both X and Y directions.
Replace the cylinder if the measured values
exceed allowable limit.
Allowable limit: 11.055 mm
Dial gauge

Measure the outer diameter of the piston.

Replace the piston if its measured value
exceeds allowable limit. Piston
Allowable limit: 10.945 mm

Micrometer

Assembly
circlip
CAUTION rubber boot
 It is necessary to replace the whole piston brake lamp
set comprising piston, spring, piston switch
cup, and circlip. rubber spring
 Make sure there is no dust on all washer
components before assembling. master
cylinder
Apply clean brake fluid to the piston cup, and
then install the cup onto the piston.
Install the larger end of the spring onto the
master cylinder.
The master cup’s cavity should be face inside
of master cylinder when installing the master
cup.
Install the circlip.
CAUTION
 Never install cup lip in the opposite
direction.
 Make sure the circlip is seated securely
in the groove.

Install the rubber pad into groove properly.

13-10
SYM 13. BRAKE

INSTALLATION master cylinder mounting seat

Place the master cylinder onto handlebar,
and install the split ring and bolts. The
“UP” mark on the split ring should face bolts x 2
upward.
Align the split ring on the master cylinder
split ring
seat with the alignment point on the
handlebar.
Tighten the upper bolt of the seat to
specified torque value, and then tighten
lower bolt to the same specified torque
value. “UP” mark

sealing washer

Install the brake lever, and connect leads to

brake lamp switch.
hose bolt
Connect brake hoses with 2 new washes.
Tighten the brake hose bolt to the specified
torque value.
Torque value: 3.5 kgf-m
Make sure the hose is installed correctly.

brake hose

13-11
13. BRAKE SYM

ABS (Anti-lock Brake System)

ABS is designed to help prevent the wheel from locking up when hard brakes are applied
while running straight. The ABS automatically regulates the brake force. Intermittently
gaining gripping force and braking force helps prevent wheel lock-up and allows stable
steering control while stopping. Brake control function is identical to that of a conventional
scooter. The right brake lever is used for the front brake and the left brake lever for the rear
brake.

Use of non-recommended tires may cause malfunctioning of ABS and can lead to extended
braking distance. The rider could have an accident as a result. Always use recommended
standard tires for this scooter.

When the ABS is functioning, rider may feel a pulsing in the brake lever. This is normal.
ABS does not function at the speed of approx. 5 km/h or below.
ABS does not function if the battery is discharged.

Single channel style (BOSCH) double channel style (CONTI)

13-12
 SYM 13. BRAKE

Single channel style (BOSCH)

Front wheel oil pressure circuit diagram

Single channel ABS only controls the front wheels,

and the rear brakes are non ABS

Configuration diagram of single channel ABS

FR. brake（right）

ABS HU

Rear ABS detective disk

Front ABS detective disk

Front disk Front caliper Rear disk Rear caliper

Front wheel speedometer Rear wheel speedometer

Single channel ABS rear brake system fails to pass HU

13-13
 13. BRAKE SYM

Double channel style (CONTI)

Rear wheel oil pressure circuit diagram

Front wheel oil pressure circuit diagram

Configuration diagram of double channel ABS

FR. brake（right）

ABS HU

Rear ABS detective disk

Front ABS detective disk

Front caliper Rear disk Rear caliper

Front disk

Front wheel speedometer Rear wheel speedometer

Dual channel ABS front and rear brake system passes HU

13-14
SYM 13. BRAKE

Front ABS detective disk Rear ABS detective disk

Single channel style (BOSCH)
45120-XMC-0001（50 holes） 43120-XJE-0001（50 holes）
Double channel style (CONTI)
45120-X93-0000（48 holes） 43120-ZBC-0001（48 holes）

ABS trouble code

Fault code NG code Problem point
C1043 5043 Front wheel speed sensor Disconnection/gnd Short/Uz Short
C1042 5042 Front wheel speed sensor malfunction -Plausibility
C1045 5045 Rear wheel speed sensor Disconnection/gnd Short/Uz Short
C1044 5044 Rear wheel speed sensor malfunction- Plausibility
C1025 5025 Deviation between Wheel speed(WSS_GENERIC)
C1017 5017 Front Inlet Valve malfunction (EV)
C1018 5018 Front Outlet Value malfunction(AV)
C1013 5013 Rear Inlet Value malfunction(EV)
C1014 5014 Rear Outlet Value malfunction(AV)
C1035 5035 Pump Motor Malfunction
C1019 5019 Value Relay malfunction(Failsafe relay)
C1055 5055 ECU malfunction
C1052 5052 Power Supply Malfunction(Low Voltage)
C1053 5053 Power Supply Malfunction(High Voltage)

13-15
13. BRAKE SYM

NOTE:

13-16
SYM 14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER

MECHANISM DIAGRAM .................... 14-1 FRONT WHEEL ................................. 14-4

PRECAUTIONS IN OPERATION ....... 14-2 FRONT SHOCK ABSORBER ............ 14-9
TROUBLE DIAGNOSIS ...................... 14-2 FRONT FORK/STEERING COLUMN 14-9
STEERING HANDLE .......................... 14-3
MECHANISM DIAGRAM

4.0~5.0kgf-m

1.0~2.0kgf-m

0.2~0.3kgf-m

3.1~3.5kgf-m
2.4~3.0kgf-m

5.0~7.0kgf-m

14-1
14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER SYM
PRECAUTIONS IN OPERATION
General Information
 Before remove front wheel, use a jack to lift the body until front wheel free of ground, and
take care not to rotate body in reverse.
 Be careful not to allow oil or grease get on brake drum or linings.

Torque values
Front wheel axle 5.0~7.0kgf-m
Steering handlebar nut 4.0~5.0kgf-m
Steering column top cone sliding ring 0.2~0.3kgf-m
Steering column lock nut 1.0~2.0kgf-m
Speedometer cable nut 0.15~0.3kgf-m
Front shock absorber: Upper nut 2.4~3.0kgf-m

Tools
Special service tools
Steering column wrench
Bearing remover
Inner type bearing remover
Attachment, 32×35 mm
Attachment, 42×47 mm
Steering column nut wrench
Steering column top cone ring nut wrench

TROUBLE DIAGNOSIS Front wheel wobbling

Hard steering stem  Deformed rim
 Over tightening of steering stem lock nut  Front wheel bearing loose
 Broken steering stem steel ball and cone  Faulty tire
bearing seat  Wheel axle nut tightened improperly
 Insufficient tire pressure
Soft front suspension
Steering stem off center  Weak fork springs
 Uneven left/right cushion  Oil leakage of the shock absorber seal
 Bend fork
 Bent front wheel/tire offset Front suspension noise
 Cushion cover friction noise
 Cushion bolts loose

14-2
SYM 14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER

STEERING HANDLE
REMOVAL
Remove handle front & rear covers and the
front cover (refer to chapter 12).

Master cylinder
Disc Brake Seat
Remove the 2 bolts of the brake master
cylinder, and then take out the master Split
cylinder and the split ring. ring
Caution
Do not operate the front brake lever to avoid
to pressing out the brake lining when Bolts x 2
removing the master cylinder.

Remove acceleration handlebar screw and

then remove the handlebar, acceleration
cable, and handlebar cover & seat.

Screw

Remove the rear brake lever nut and screw, Brake lever screw
Remove the brake seat bolt, and then Brake lever nut
remove the seat.

Brake seat bolt

14-3
14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER SYM

With a wrench to hold the handlebar bolt and

Bolt
then remove the nut.
Take out the handlebar after removed the
bolt.

Nut

Installation
Install the handlebar according to the
reverse procedure of removal.
Apply with some grease onto the handlebar
moving parts when installing the acceleration
handlebar seat, acceleration handlebar, and
acceleration cable.

FRONT WHEEL
Removal Speedometer cable
Disc Brake type
Support body bottom and lift front wheel free
of ground.
Remove the bolts, and disconnect
speedometer cable from the gear box.

Remove the wheel axle nut and pull out the

axle. Then, remove the front wheel.
Caution
Do not operate the front brake lever to
avoid to pressing out the brake lining
when removing the master cylinder.

Wheel axle nut

14-4
SYM 14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER

Inspection
Wheel axle
Set the axle in V-blocks and measure the
run-out.
Service limit: 0.2 mm.

Wheel axle

Wheel Rim
Place the wheel onto a rotated bracket.
Turn the wheel with hand and measure its
wobble value with a dial gauge.

Service limit:
Radial : 2.0 mm
Axial : 2.0 mm

Disassembly (Disc type)

Remove 5 hex socket bolts and brake disc.

14-5
14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER SYM

Remove the left axle ring and dust seal. Speedometer gear dust seal
DISC BRAKE
Remove the dust seal on the right side of
speedometer gear.
Remove the bearing with the inner type Bearing spacer
bearing remover. Bearing
Take out the bearing spacer and then
remove the other bearing.
Tool:
Inner type bearing remover Bearing

Dust seal
Wheel side collar

Bearing Inspection Clearance

Turn the inner race of bearing with fingers.
Clearance
The bearing should be turn smoothly. Also
check if the outer collar is tightly connected
to the wheel hub.
If the bearing do not turn smoothly, or if they
are too loose in the races, or damaged, then,
remove and replace the bearings with new
ones.
Caution
The bearing must be replaced in pair.

Installation
Install the bearing according to the reverse
procedure of removal.
Apply some grease into the bearing seat of
the wheel hub.
Install the left bearing onto the seat.
Install the bearing spacer and then install
the right bearing onto the seat.

14-6
SYM 14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER

Caution
 Do not install used bearing and replace
the bearing once it has been removed.
 Do not the bearing in tile motion when
installing.

Tool:
C-type compressor or bearing compressor.
This two example will to louse the bearing.

Speedometer gear dust seal

DISC BRAKE
Disc Brake
Apply with some grease inside of the dust
Bearing spacer
bearing.
Install the dust seal and the front wheel side Bearing
collar.
Apply with some grease on both side of the
speedometer gear oil seal, and then install
the seal. Bearing

Dust seal

Wheel side collar

14-7
14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER SYM

Align the flange part on the speedometer

gear with the slot of wheel hub, and then
install the brake disc (drum brake) or
speedometer gear box.
Caution
Contaminated brake lining will reduce
brake performance so the brake lining,
brake drum and disc must be free of
grease.

Stopper
Place the front wheel between the front
shock absorbers.

Disc Brake
Align the flange part on the speedometer
gear with the slot of shock absorber stopper.

Disc Brake Gear box flange part Brake panel slot

Install the front wheel axle from right shock
absorber side.
Install the wheel axle nut, and tighten it to
specified torque value.
Torque value: 5.0~7.0kgf-m
Connect the speedometer cable to the
speedometer gear box.

Wheel axle nut Speedometer cable

14-8
SYM 14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER
FRONT SHOCK ABSORBER
Removal
Remove the front fender, front lower spoiler,
front guard, and front wheel as well as front
brake components.
Remove the brake fluid hose clipper or cable
guide on the left shock absorber. (bolt x 1)
As for disc brake, remove the cable guide on
the right shock absorber. (bolt x 1)
Brake fluid
hose clipper

Remove the top connection bolt of the right Bolts

shock absorber. (bolt x 4)
Remove the shock absorber from the front
fork.

Shock absorbers

Installation
Install the shock absorbers according to the
reverse procedure of removal.
Align the shock absorber top-edge with the
top-end level of the front fork when installing
the front shock absorber onto the front fork.
Then, tighten the nut.
Torque value: 2.4~3.0kgf-m

FRONT FORK/STEERING COLUMN

Removal
Steering column nut
Firstly, remove the handlebar, front wheel,
front brake set, and front shock absorbers.
Remove the steering column nut.
Remove the top cone ring, and then remove
the steering column.
Caution
Place the steering column bearing balls
into a parts container to avoid to
missing or shortage. Top cone race

14-9
14. STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER SYM

With a plastic hammer to tap the steering

column slightly, and then remove the top ball
bearing seat.
Remove the lower-end cone bearing seat on
the frame with a punch.
Caution
Do not damage the frame and the steering
column.

Installation
Install a new top-cone bearing seat onto the
top of steering column.
Lower all bearing seat Steering column nut
And then, push the lower-cone bearing seat
from bottom until to locking position. Balls

Caution Lower cone-race

Do not let the ball bearing in title motion as Top cone-race

installation.
Balls

Apply with some grease onto the top &

bottom bearing balls, and then install the Top ball bearing seat.
balls into bearing seat.
Press in a new lower cone-race onto the
steering column, and lubricate it with grease.
Install the steering column.
Steering column nut
Lubricate the top-cone race with grease.
Drive the cone-race into the steering column
Return 1/2 turn
until contact with the top bearing seat no
clearance. Note, return 1/2 turn and then
tighten the top cone race to specified torque.
(tighten the race around 1/4~3/8 turn more.)
Torque value: 0.2~0.3kgf-m Locking to
1/4~3/8 turn
Caution
Do not tighten the top cone race too tight
to prevent from damage the ball bearing Top cone-race
seat when tightening the top cone race.

Install the steering column nut and lock the Steering column nut
top cone race. Then, tighten the nut.
Torque value: 1.0~2.0kgf-m
Install the bearing seat according to the
reverse procedure of removal.
Caution
Check the steering column if it can be
turned freely and no clearance in vertical
motion. Top cone-race

14-10
SYM 15. REAR WHEEL/REAR SHOCK ABSORBER

MECHANISM DIAGRAM .................... 15-1 EXHAUST MUFFLER......................... 15-3

PRECAUTIONS IN OPERATION ....... 15-2 REAR WHEEL .................................... 15-3
TROUBLE DIAGNOSIS ..................... 15-2 REAR SHOCK ABSORBER ............... 15-4

MECHANISM DIAGRAM

3.5~4.5kgf-m

2.4~3.0kgf-m

1.0~1.4kgf-m

11.0~13.0kgf-m
3.0~3.6kgf-m

15-1
15. REAR WHEEL/REAR SHOCK ABSORBER SYM

PRECAUTIONS IN OPERATION
General Information
As for the wheel removal, service, and installation procedures, please refer to the service
manual of high speed tire.

Specification Unit: mm
Items Standard Limit
Radial - 2.0
Wheel wobbling
Axial - 2.0
Thickness of rear brake lining 4.0 2.0

Torque values:
Rear axle nut 11.0~13.0kgf-m
Rear shock absorber upper mount bolt 3.5~4.5kgf-m
Rear shock absorber lower mount bolt 2.4~3.0kgf-m
Exhaust muffler connection nut 1.0~1.4kgf-m
Exhaust muffler connection bolt 3.0~3.6kgf-m

TROUBLE DIAGNOSIS
Rear wheel wobbling Braking Noise Poor brake performance
 bend wheel rim  worn brake lining  Poor brake adjustment
 poor tire  brake drum deformation  contaminated brake
 loosen wheel shaft  improperly brake panel lining
installation  worn brake lining
Shock absorber too soft  unparalleled brake drum  greased brake drum
 insufficient shock or wheel unparallel.  contaminated and
absorber spring force seized brake cable
 improperly installation of
brake cable

15-2
SYM 15. REAR WHEEL/REAR SHOCK ABSORBER

EXHAUST MUFFLER Exhaust muffler

Removal
Remove the front-end nut of the exhaust
muffler. (nuts x 2)
Remove the bolts. (bolts x 2)
Remove the exhaust muffler.

Installation
Install the exhaust muffler according to the
reverse procedure of removal.
Caution Nuts x 2
Replace the exhaust muffler gasket if it is
broken or deformed. Bolts×2

Torque value:
Exhaust muffler connection bolt:
3.0~3.6kgf-m
Exhaust muffler connection nut:
1.0~1.4kgf-m

REAR WHEEL
Inspection
Measure wheel rim wobbling.
Service limit:
Radial: 2.0mm
Axial: 2.0mm
If the wheel rim wobbling out of the
specification, except resulted from the
wheel rim deformation, it might be loosen or
worn final driving shaft bearing or bend,
deformed driving shaft.

Removal
Remove the exhaust muffler . (bolts x 2)
Remove the rear wheel. (wheel axle nut x1)

15-3
15. REAR WHEEL/REAR SHOCK ABSORBER SYM

REAR SHOCK ABSORBER

Removal
Remove the luggage box. (bolts x 6)
Remove the rear carrier. (bolts x 3)
Remove the left & right body covers. (screws
x 4, bolts x 2)
Remove the air cleaner bolts (bolts x2)
Remove the lower nut of the rear shock
absorber (bolt x 1)
Remove the upper nut of the rear shock
absorber (bolt x 1)
Remove the rear shock absorber . rear shock absorber

Installation Upper mount bolt

Install the rear shock absorber according to
the reverse procedure of removal.
Caution
The rear shock absorber has to be replaced
with one set and can not be replaced by
unauthorized persons. Otherwise, it might
damage the rubber bushing and
construction.
Lower mount bolt
Torque values
Rear shock absorber lower mount bolt:
2.4~3.0 kgf-m
Rear shock absorber upper mount bolt:
3.5~4.5 kgf-m

15-4
SYM 16. ELECTRICAL EQUIPMENT

MECHANISM DIAGRAM .................... 16-1 STARTING SYSTEM .......................... 16-14

PRECAUTIONS IN OPERATION ....... 16-2 METER ............................................... 16-15
TROUBLE DIAGNOSIS ...................... 16-4 LIGHTS/BULBS .................................. 16-17
CHARGING SYSTEM......................... 16-5 SWITCH ............................................. 16-19
IGNITION SYSTEM ............................ 16-11 FUEL UNIT .........................................16-22
MECHANISM DIAGRAM

Rear stop switch Horn/turn signal

light/high & low beam

Horn
REG.REC

Side stand switch

starter switch
Starter magnetic switch
Main switch Front stop switch
Fuel unit

Winker relay

Battery
ECU

Ignition coil

Spark plug

16-1
16. ELECTRICAL EQUIPMENT SYM
PRECAUTIONS IN OPERATION
Charging System
 When remove the battery, the disconnection sequence of cable terminals shall be strictly observed.
(First disconnect the negative cable terminal, next, the positive cable terminal.)
 MF (Maintenance Free) battery does not need to check, add electrolyte or distilled water.
 Battery must be taken out from scooter when charging the battery. But do not open the battery caps.
 Do not quick charge the battery unless in emergency.
 A voltmeter must be used when checking battery charging condition.
 Battery can be charged or discharged alternately. To set a discharged battery idle for a prolonged
period will shorten its service life and reduce its capacity. Usually, battery’s capacity will reduce after
1~2 years. After low capacity battery was charged, its voltage will increase. If it connects to an
additional load, the voltage will reduce suddenly, and then go up again.
 Over-charged battery. Usually, the over-charged battery can be seen externally. If a short circuit
occurred inside the battery, there will be no voltage on the terminals of battery if voltage regulator does
not operate. Then, the battery’s voltage will be too high that may reduce battery’s life.
 The battery will be self-discharged if it was set idle for a long time. An idle battery must be charged
about every 2months.
 A new battery filled with electrolyte will generate a voltage after filled out electrolyte. The voltage
should be in 12.5V or more after 10 minutes. When electrolyte is not enough, the battery must be filled
with electrolyte and then charged to prolong the battery’s life-span.
 Please check electrical device according to the procedure of diagnosis chart.
 Do not disconnect and connect the connector of electrical devices when current is passing these
devices because this will generate high voltage and the electrical components in the voltage-current
regulator will be damaged. The ignition switch must be turned OFF before performing any work.
 Please do not replace with traditional type battery as replacement.
 Please refer to the removal instruction when removing the alternator and the pulse generator.

Ignition System
 Please follow the procedure of trouble diagnosis chart to check ignition system.
 The ignition system equipped with a auto-advanced timing device in CDI unit. Thus, ignition timing
need not to be adjusted. In case of incorrect ignition timing occurred, check the CDI unit or alternator
system. It has to check the ignition timing with the ignition timing light if replaced these components.
 Do not hang or impact the CDI unit of ignition system because the major faulty of CDI unit is caused
by impact. Therefore, take care when disassembling.
 Most of ignition system problems were resulted from poor connecting connector. Please check the
connectors first when servicing.
 Make sure that the heat range of spark plug is suitable. Improper spark plug is the main cause of poor
engine operation or combustion.
 Inspection procedures in this manual are based on Max. voltage. This manual also contains methods
of how to check ignition coil resistance and component operation.
 Please follow the continuity chart to check ignition switch.

Starting System
 Starting motor can be removed directly from engine.
 Please refer to chapter 10 for starting clutch removal procedures.

16-2
SYM 16. ELECTRICAL EQUIPMENT
Specification
Charging System
Items Specification
Capacity/type 12V 6Ah
STD:0.6A/5~10hrs, emergency charging:
Charging rate
Battery 6A/0.5hrs
Voltage Full charged 13.1V
(20℃) Under charged 12.3V
Capacity 12V / 6.2A
Alternator Lighting coil resistance (20℃) Between yellow-green: 0.8±0.1Ω
Charging coil resistance (20℃) Between white-green: 0.6±0.1Ω
Leaking current Less 1mA
RPM for starting charging 1700rpm(headlight ON)
Voltage controlled by regulator 14.5±0.5 V
Resistance (20℃) 5W5Ω 4.5~5.5Ω
Resistor
Resistance (20℃) 30W7.5Ω 7.0~8.0Ω
Ignition System
Item Specification
Standard NGK CR7HSA (Recommended usage)
Hot type NGK CR8HSA
Spark plug
Cold type NGK CR6HSA
Spark plug gap 0.6~0.7 mm
Primary 0.21±10%Ω
Ignition coil resistance
With plug cap : 7.6±10%KΩ
(20℃) Secondary
Without plug cap : 3.1±10%KΩ
“F” Mark Before TDC 13° / 1700 rpm
Ignition timing Timing advanced Before TDC 28° / 4000 rpm
character Before TDC 27° / 8000 rpm
Pulse generator resistance (20℃) 50~200Ω
Exciting coil resistance (20℃) 400~800Ω
Ignition coil-primary max. voltage 95~400 V
Pulse generator voltage 1.7 V above
Exciting coil voltage 95~400 V

Starting System
Item Specification
type DC TYPE
Starting motor
capacity 0.5 KW

16-3
16. ELECTRICAL EQUIPMENT SYM
TROUBLE DIAGNOSIS
No voltage Intermittent power supply
 Battery discharged  The connector of the charging system
 The cable disconnected becomes loose
 The fuse is blown  Poor connection of the battery cable
 Improper operation of the main switch  Poor connection or short-circuit of the
 Low voltage discharging system
 The battery is not fully charged  Poor connection or short-circuit of the
 Poor contact power generation system
 Poor charging system
 Poor voltage regulator Charging system does not operate properly
 Burnt fuse
No spark produced by spark plug  Poor contact, open or short circuit
 The spark plug is out of work  Poor regulator rectifier
 The cable is poorly connected, open or  Poor ACG
short-circuited
 Poor connection between ECU and Engine does not crank smoothly
ignition coil  Primary winding circuit
 Poor connection between ECU and the - Poor ignition coil
main switch - Poor connection of cable and
 Poor main switch connectors
 Poor ECU. - Poor main switch
 A.C.G. is out of work  Secondary winding circuit
- Poor ignition coil
Starter motor does not work - Poor spark plug
 The fuse is blown - Poor ignition coil cable
 The battery is not fully charged - Current leakage in the spark plug
 Poor main switch  Incorrect ignition timing
 Poor starter switch - Poor ACG
 The front and rear brake switches do not - Improper installation of CPS
operate correctly - Poor ECU
 Starter relay is out of work
 The ignition coil is poorly connected, open Weak starter motor
or short-circuited  Poor charging system
 The starter motor is out of work  The battery is not fully charged
 Poor connection in the windings
 The motor gear is jammed by foreign
material

Starter motor is working, but engine does

not crank
 Poor starter motor pinion
 The starter motor runs in reverse direction
Poor battery

16-4
SYM 16. ELECTRICAL EQUIPMENT

Battery Battery cover

Removal
Remove the battery cover.

CAUTION
 Electrolyte (diluted sulfuric acid) is very
toxic. Once it spreading on clothes,
skin, or eyes, it will cause burned or
blind. In case of being spread, flush
with great quantity of water immediately,
and then send to hospital.
 When clothes is spread by electrolyte, it
will contact with skin. So, it must flush
with great quantity water to take off the
clothes.

Negative cable (-)

Remove the battery cover.

Fuse box Positive cable (+)

Disconnect the negative (-) cable from the

battery first, then the positive (+) cable.
Remove the battery.

Negative cable (-) Positive cable (+)

Install the battery in reverse order of

removal.
 ToCAUTION
prevent form circuit short, connect
positive(+) terminal at first, and next
negative (-) terminal.

16-5
16. ELECTRICAL EQUIPMENT SYM
Voltage Check
With a digital voltage meter or multi-meter to
measure battery voltage.
Voltage:
Fully charged: 13.0 – 13.2V (at 20℃)
Undercharged: Below 12.3 V (at 20℃)

CHARGING
Connect the Charger positive (+) to the
battery positive (+) terminal.
Connect the Charger negative (-) to the
battery negative (-) terminal.

Standard Max.
Charging
current 0.6A 6.0A

Charging time 5~10H 1H

Warning
 Strictly keep flames away from a charging
battery.
 The charging “ON”/ “OFF” is controlled by
the charger’s switch. Do not control the
charging by battery jump wires.
 Turn the charger’s switch “OFF” at first
before or after charging to prevent from
sparks created on the connectors and
explosion.
 To charge a battery must be based on the
battery’s ampere-hour showed on label.

CAUTION
 Quick charge a battery should be used
only in an emergency.
 Make sure the current and charging time
of above description.
 The battery will be damaged by too much
current or too rush charging.
 When finishing charge, it is necessary to
measure voltage after 30 minutes.

After installing the battery, coat the terminals

with clean grease.

16-6
SYM 16. ELECTRICAL EQUIPMENT
digital voltmeter
Charging Voltage/Current
ammeter
Inspection
Caution
 Before conducting the inspection, be
sure that the battery is fully charged. Use
a fully charged battery having a voltage
larger than 13.1 V. If undercharged, the
current changes dramatically.
 While starting the engine, the starter
Fuse ends
motor draws large amount of current
from the battery. Thus, do not start the
engine with battery.
Connect a tachometer.
Turn on the headlight to high beam and start the
After the engine is warmed up, replace engine.
original battery with a fully charged battery. Accelerate the engine gradually to the specified
Connect a digital voltmeter to the battery revolution per minute and measure the charging
terminals. voltage/current.
Connect an ammeter between both ends of Specified Charging Current:
the main fuse. (headlight OFF) 0.6 A or more/2500rpm
1.2 A or more / 6000 rpm
(headlight ON) 0.4 A or more/2500rpm
Caution 1.0 A or more / 6000 rpm
When the probe is reversibly connected, use Control Charging Voltage:
a voltmeter having an indication that the 14.0+/0.5 V / 2000 rpm
current flows from the positive or the Caution
negative direction and the measurement
To replace the old battery, use a new battery
should be at zero, ammeter at one direction
with the same current and voltage.
only.
The following problems are related to the
charging system, follow the instructions
Caution provided in the checking list to correct it if any
 Do not use short-circuit cable. one of the problems takes place.
 It is possible to measure the current by (1) The charging voltage can not exceed the
voltage between two battery terminals and
connecting an ammeter between the the charging current is in the discharging
battery positive terminal and the cable direction.
position terminal, however, while the (2) The charging voltage and current are too
starter motor is activated, the surge much higher than the standard values.
current of the motor draws from the The following problems are not related to the
battery may damage the ammeter. Use charging system; correct it if any by following
the kick lever to start the engine. steps indicate in the checking list.
 The main switch shall be turned to OFF (1) The standard charging voltage and current
position during the process of inspection. can only reach when the revolution of the
Never tamper with the ammeter and the engine exceeds the specified rpm.
cable while there is current flowing  Bulbs used exceed their rate and
through. It may damage the ammeter. consume too much power.
 The replacement battery is aged and
does not have enough capacity.
(2) The charging voltage is normal, but the
current is not.
 The replacement battery is aged and
does not have enough capacity.
 Battery used do not have enough
electricity or is over charged.
 The fuse of the ammeter is blown.
 The ammeter is improperly connected.
(3) The charging current is normal, but the
voltage is not.
 The fuse of the voltmeter is blown.
16-7
16. ELECTRICAL EQUIPMENT SYM
VOLTAGE REGULATOR INSPECTION Winker relay
Remove the front cover. (screws 4 x 2). REG.REC
Remove the front cover mounting bolt(bolt x
1)and remove the left/right turnlight wiring
connector.
Disconnect the 4P connector on the diode,
and check the continuity between main wire
terminals according to following method.
Main wire circuit inspection
Item (wire color) Judgment
Check voltage between Battery voltage
battery terminal (red) and Horn
ground (green).
Check continuity between Continuity Headlight wiring connector
ground(green) and frame.
Check illumination wire
(yellow) to ground.
(disconnect the connector of Continuity &
the resistor’s pin and resistance
automatic by-starter pin.
Illumination switch is in OFF)
Check charging coil (white) to Continuity &
ground) resistance
If the measured value is abnormal, check the
abnormal wire circuit. If components are
good, it could be a poor wire circuit.
If all items are in good condition, then
replace the voltage regulator.
If main wire circuit check is in normal and
there is no loose in the pins of voltage
regulator connector, then measure the
resistance between the connector of voltage
regulator.
Voltage Regulator Check Unit: Ω
black
yellow yellow yellow black red green shell
red
yellow ∞ ∞ ∞ ∞ 4 ∞
yellow ∞ ∞ ∞ ∞ 5 ∞
yellow ∞ ∞ ∞ ∞ 5 ∞
black ∞ ∞ ∞ ∞ 8 ∞
red 5 5 5 ∞ 12 ∞
green ∞ ∞ ∞ ∞ ∞ ∞
shell ∞ ∞ ∞ ∞ ∞ ∞
Caution
 Do not touch the probe of multi-meter by
fingers, then the resistance values will be
incorrect because there is some resistance
existence in human body.
 To use the multi-meter recommended by
SYM. Otherwise, the measured resistance
might be different.
16-8
SYM 16. ELECTRICAL EQUIPMENT
Alternator charging coil Charging Auto
coil/light coil by-star
Caution
connector
The check of alternator charging coil and
illumination coil can be done when the
alternator is mounted on engine.

Pulse generator
connector

Check
Remove the 2P connector of the alternator.
Measure the resistance between the white
wire on yellow wire with a multi-meter.
Standard: 0.6±0.1Ω (20℃)
Replace the alternator charging coil if the
measured value exceeds standard.

16-9
16. ELECTRICAL EQUIPMENT SYM
Ignition coil
Removal Ignition coil
Remove the luggage box, center cover.
Remove spark plug cap.
Remove the primary coil wire of ignition coil.
Remove the fix bolts for the ignition coil, and
remove the ignition coil.
Install the ignition coil in reverse order of
removal.
Caution
Install primary coil with black/yellow lead
connected to black connector and green lead
connected to green connector.

Spark plug confirmation

Remove the spark plug and install a good
plug into plug cap, and then ground it to
engine ground.
Make sure its spark condition. If it is in not
good or burnt spark plug, replace the spark
plug with new one.
Caution

 Make sure each wire connection is correct,

and test as required. Even the wire
connection is in correct, sometimes, it
might not be tested occurred. black/yellow
Connect the high voltage shunt with a
multi-meter or input a resistor in the 10MΩ
100V of voltage meter.
Connect ignition coil wires, and connect a
shunt between primary terminal (black/yellow
and green) and frame ground. green
Press the starting motor button, or starting
lever to test the max. primary voltage of
ignition coil.
Connection: connect (+) terminal to green
side, and (-) to black/yellow side. high voltage shunt
Min. voltage: Above 95 V.
Caution
Do not touch metal parts on the test probe
with fingers to avoid electric shock.
Primary coil check
Disconnect the primary coil connector and
check the resistance between primary coil
terminals.
Standard: 0.21Ω±10%Ω(at 20℃)
Primary coil is good if resistance within
standard.
Primary coil is broken if resistance is infinite.
Replace the coil.

16-10
SYM 16. ELECTRICAL EQUIPMENT
Secondary coil
Attached the spark plug cap, measure the
resistance between plug cap side and green
terminal.
Standard value: 7-12 kΩ(20℃)
Remove the spark plug cap, measure the
resistance between plug cap side and green
terminal.
Standard value: 3-5 kΩ(20℃)
Secondary coil is good if resistance within
standard.
Secondary coil is broken if resistance is
infinite. If the spark plug cap attached and
the measured value is exceed standard
value, it means the spark plug cap is in not
good. Ignition coil

Replacement
Remove the ignition coil bolt to replace the
ignition coil if necessary.

Pulse generator
Caution
Checking pulse generator can be done on
engine. But, the spark plug must be
installed onto the cylinder head, and
cylinder compression pressure must be in
normal condition.

Check
Remove body cover.
Remove the pulse generator connector.
Measure the resistance between blue/yellow
terminal on engine side and frame ground.
Standard: 140±20Ω(20℃)
Replace the alternator if the measured value
exceeds standard value.

16-11
16. ELECTRICAL EQUIPMENT SYM

STARTING SYSTEM
Starting Circuit

Starter magnetic switch inspection Starter magnetic switch

Turn main switch to "on", and operate the
brake lever. Then press starting button to
check if there a click sound. It is normal if
there is a click sound.

Remove the luggage box.

Disconnect the battery negative (-) terminal.
Remove the battery positive (+) connection Starter magnetic switch
and starting motor wires from the starter
magnetic switch large pin.
Remove the power control connector of the
Starter magnetic switch.
Connect a Ohmmeter between the Starter
magnetic switch large pins.
Connect the green/yellow wire to battery
positive (+) terminal, and yellow/red to
battery negative (-) terminal.
Check the continuity between the Starter
magnetic switch large pins. If it is not
continuity, then replace the starter magnetic
switch.

16-12
SYM 16. ELECTRICAL EQUIPMENT
Starting Motor Removal Bolts x2
Remove the battery cover.
Firstly, remove the battery negative (-)
terminal, and then remove the positive (+)
terminal.
Remove the luggage box.
Remove the starting motor power wire.
Remove the starting motor mounting bolts
and motor.

Starting Motor Installation

Install the motor in reverse order of removal.

METER
Removal
Remove the front cover.

Meter

Remove the speedometer cable.

speedometer cable

Meter connector
Remove the front cover.
Remove the power connector of the meter.

16-13
16. ELECTRICAL EQUIPMENT SYM
Remove the front cover.
Remove the meter mounting screws.
Take out the meter.

Turn Left
Signal Indicator Turn Right
Signal Indicator
Engine oil
replacement warning
Fault indicator light

Voltmeter/time

High Beam
Indicator
Cooling temperature
Indicator
Trip Kilometer/
Odometer

ABS Indicator Fuel meter

Speedomete
r
Caution
Do not wipe the meter or headlight with organic solvent such as gasoline to prevent from
damage these components.
Installation
Install the meter in reverse order of removal.

16-14
SYM 16. ELECTRICAL EQUIPMENT
LIGHT/BULBS
Headlight Bulb Replacement
Rear the front handle cover.
Disconnect the headlight wire connector.
Press down the bulb spring locker and then
remove the locker with turning it left motion.
Remove the bulb.
Replace the bulb with new one if necessary.
(12V 35/35W)

Caution
 Do not touch the bulb surface with fingers
because the bulb will create hot-spot so
that let it be burnt. It has to be package
with cloth or wear glove as installing.
 Wipe the bulb with cloth to prevent from
damaged if the bulb be touched by hands.

Install the bulb in reverse order of removal.

Turn the main switch ON/OFF to check if the
bulb has been installed properly after
installation.

Please conduct the headlight beam

adjustment job if replace the headlight bulb.

The headlight beam adjustment

Loosen the adjustment bolt located under the
headlight.
Caution
 This outer cover of headlight is a fixed type
so that the light seat will be moved only
when adjusting.

16-15
16. ELECTRICAL EQUIPMENT SYM
Front Turn Signal Lamp Bulb
Replacement
Remove the front handle cover. Front turn signal light
Remove the wire connector of the turn signal
light.

the wire connector

of the turn signal
Pull out the bulb and replace it with new one. light
(12V 10W)

Installation
Install the bulb in reverse order of removal.

turn signal light

Bulbs Replacement of tail light/brake
light/rear turn signal light.
Remove the 2 screws of the taillight
&left/right turn light lens.

Remove the tail light assembly.

Installation Screw x 2
Install the bulb in reverse order of removal.

16-16
SYM 16. ELECTRICAL EQUIPMENT
MAIN SWITCH/HORN
Main Switch main switch connector terminals
Check
Remove the headlight connector and the front
cover.
Disconnect main switch leads connector.
Check connector terminals for continuity.
color
Black Red
Location
LOCK

OFF
main switch bolts x 2
ON ● ●

Replacement
Remove the main switch connector and
fixing bolts (bolts x 2)
Remove the main switch.
Install a new main switch and tighten the
bolts. (bolts x2)

16-17
16. ELECTRICAL EQUIPMENT SYM
Handle switch
Remove the front handle cover.
Disconnect the connector of the handle switch.
Check the continuity of follow pins listed
below columns.

starting switch

Starting switch
color
Yellow/red Yellow/green
Location
FREE

● ● Starting
switch

yellow/red yellow/green

High/Low beam switch/ seat open

color brown/
blue white black purple
Location white High/Low beam
switch/ seat open
● ●

● ● turn signal switch

seat open ● ● ● ●
horn switch

Horn switch purple

High/Low beam
white/green switch/ seat open
color
White/green blue/green
Location white
blue
white/green
FREE orange
turn signal
● ● switch
gray
Sky blue
blue green
white/green
Horn switch

16-18
SYM 16. ELECTRICAL EQUIPMENT
Turn signal light switch
color Sky
Gray orange
Location blue
● ●
turn signal
FROM R ● ● orange light switch
N PUSH OFF
FROM L ● ●
Sky blue gray
● ●

Brake light switch

The circuit of black wire and the
green/yellow wire on the brake light switch
should be in continuity when operating the
brake lever.
If the switch damaged, replace it with new
one.

Horn
Remove the front cover.
Connect the light blue wire on the horn to the
battery positive (+) terminal, and the green
wire to the battery negative (-) terminal.
Then, the horn should sound.
Replace it if necessary.

16-19
 ground
Alternator
Battery(-)
battery
use(15A
yellow
green
In
white
Auto
red
the )
REG.REC
wire
by-starter
erminal
current
.
leakage
16.
test, set ELECTRICAL EQUIPMENT SYM
the
FUEL UNIT
Fuel unit
Open the seat.
Remove the luggage box(bolts x 4) .
Remove the R.R. carrier(bolts x 3) .
Remove the body cover.
Disconnect the fuel unit wire connector.

Caution
Do not damage or bend the float arm as
removing.

The resistance values are listed below when

the float arm in “F” and “E” positions.
Float arm position Resistance value

E(empty) 97.5~107.5Ω

F(full) 4~10Ω
UP
DOWN(empty)Connect the fuel unit to the (full)
main harness.
Turn the main switch “ON” position.
Move the float arm in “UP” & “DOWN”, and
then check if the fuel unit indication needle is
in correct position.
Caution DOWN
Turn on the turn signal light to make sure (empty)
battery is in good condition before this test.

Float arm position Indicator needle

UP(full) E(empty)

DOWN(empty) F(full)

Installation
Install the fuel unit in reverse order of removal.

16-20
 XC20W2-EU (X9M) ELEC.DISTRIBUTION
RH. FR. POSITION BULB SIDE STAND
(12V LED*27颗) COMB. SW.
COLOR
SENSOR OBD
BR FR. STOP SW. RR. STOP SW. FUNCTION
BAT BAT1 BAT2

ENG
COLOR
G L/Y Y/G

SIGNAL GROUND
功能

SPEED SENSOR INTPUT

G FUNCTION

ENGINE TEMPERATURE
START SW. A 熄火
O2 SENSOR INJETCTOR ET SENSOR POWER RELAY CONTROL SW.

IGNITION COIL

BATTERY+
HEGO HEAT-UP
LOCK IGN.COIL

ACG PULSE-
B

ACG PULSE+

GROUND
FUEL PUMP

O2 SENSOR
熄火

CAN-H
BATTERY+
INJECTOR

CAN-L
RPM OUT

GROUND
GROUND
COLOR
2P

CAN-H

CAN-L

VBK
Y/G Y/R C

CHTS
EFI-
起动

VBK
FUNCTION

1 3 5 8 11 12 13 15 18 19 20 23 25 26 27 29 30 34 16P

P/B

G/R
P/W
R/Y

B/R
1 4 5 6 14 16

G/R
D 熄火

B
R
B
G/Y

G/Y
W/G

W/G
FREE

G/L
R/Y
6P 4P 2P

Y/G

W/B
34P

O/P

R3
BG
BG
B2
G
4P 2P

Y/L
L/Y
G/Y

G/Y
0001

W/G

W/G
3P

PU/R
P/W

G/L

Y/L

B/L

B/Y

B/R
O/G

G/R
R/Y
B/O

P/B

P/B
R/Y
G/R
P/W
Y/G
Y/R

G/W

O/B
O/P

G/R
B/R
BG

BG

W/B
R3

R3
B1

R/Y
Y/G

B/Y
R/Y
B2
R3
RH. FR. WINKER BULB 0001

Y/G
G
SB
(RY10W 12V) G
0001

W1
L1
G

G
L1
W1

HEAD LIGHT
(12V LED 33W*2/19W*2)
G
W1
RELAY
POWER

4P

BR
W
RH. RR. WINKER BULB
(RY10W 12V)
Y/R Y/R SB
2P
Y/G G G
G/Y G/Y
ELEC. METER G/Y
2P

电子液晶仪表 W/G 2P
TAIL/STOP LIGHT
EFI PU/R
W/G
PU/R
W/G
PU/R
(12V/LED)
FUEL+ Y/W Y/W Y/W
L
HI BEAM
TURN R SB
L
SB
L
SB SB SB
位置灯18颗
RPM B/L B/L 9P B/L G/Y G/Y 刹车灯24颗
IGN.(+) W/G W/G W/G W/G BR
SPEED O/B O/B O/B G 6P
G
TURN L O O O O O G
ABS Y/L Y/L Y/L(1) O
BAT.(+) R3 R R3
FUEL- & GND BG BG 3P BG LH. RR. WINKER BULB
ILLUMI BR BR W/G
(RY10W 12V)
B W/G G
SB SB BR
L L
G
6P
G LICENCE LAMP
G
L1
B
BR
W/G
W/G
(W5W 12V)
RELAY
POWER

4P

BR PU 1P PU
L

O O O
2P
G G G

LH. FR. WINKER BULB

(RY10W 12V)

R1

BG
BR
G
2P

W/G
G
Y/R
G/Y
SB

BR

R
W
L
O

G
W/G
B/O

R/B
2P

R1
R3
B2

B1

R2
6P 2P

W/G
G
START MOTOR（0.5KW)

G/B
Y/R
G/R
SB

BR

G
W
L
O

0001 USB

25A
20A
15A
15A
10A

15A
LH. FR. POSITION BULB BATTERY
M
W/Y
W/L

(2A)
(12V 6AH)

Y1
Y2
Y3
Y/L(1)

2P
(12V LED*27颗)
G/B1
R/B
W/Y

L/R

O/B

W/B

W/L

L/W

O/P
B2
L/W
L/R

G
W/L
W/Y

G/W
L/Y
3P

Y1
Y3
Y2
R2
2P
G

FUSE BOX ASSY. FRAME EARTH

PU
G

18P 3P 2P
L/R
L/W

R/Y
Y/W

O/G
2P
START MAG.
BG

Y1
Y2
Y3
18 KL30（BATTERY+)
17 F-SIG
16 PCC-1（程序选择）
15 R-SIG
14 PCC-2（程序选择）

11 CAN-L
10 GND

1 PCC-0(程序选择）
7 NO USE
5 ISO-K
3 WL-ABS
6 R-SS GND (VOLTAGE +)

2 CAN-H
9 NO USE
8 F-SS GND (VOLTAGE +)

4 IGNITION
13 TACHY（SPEED OUT）
12 ABS-OFF

2P

G/W
L/Y
4P
F SP SENSOR 2P
Y1
Y3
Y2
LG

0001
R
G
G

PU
GR
PU

SB
GR

LG

G
B
W
L
B

P
Y/W

R SP SENSOR
BG

FROM R FREE REG. REC. FUEL PUMP

SEAT OPEN N PUSH OFF
COLOR

FUNCTION
W/G
WINKER
LG DC (3相 15A)
ACG.（3相 18极)
COLOR
W/G W L W/G PU
HORN SW. RELAY
FROM L
FUNCTION

SOLENOID
DIMMER SW. COLOR
SB GR O HORN
FUNCTION

FUEL UNIT ABS ECU

WINKER SW. FRAME
CORD COLOR FULL NAME LIST:
代号 英文 中文 代号 英文 中文
BG BOTTLE GREEN 深绿色 O ORANGE 橙色
Y YELLOW 黄色 GR GRAY 灰色
L BLUE 蓝色 SB SKY BLUE 天蓝色
G GREEN 绿色 LG LIGHT GREEN 浅绿色
R RED 红色 PU PURPLE 紫色
W WHITE 白色 P PINK 粉红色
B BLACK 黑色 BR BROWN 棕色