HYOSUNG MOTORS & MACHINERY INC.

SERVICE MANUAL
SERVICE MANUAL

99000-91310

FOREWORD
This manual contains an introductory description on
HYOSUNG PRIMA(SF-50) and procedures for its inspection/service and overhaul of its main components.
Other information considered as generally known is
not included.
Read GENERAL INFORMATION section to familiarize
yourself with outline of the vehicle and MAINTENANCE and other sections to use as a guide for
proper inspection and service.
This manual will help you know the vehicle better so
that you can assure your customers of your optimum
and quick service.

* This manual has been prepared on the basis of

the latest specification at the time of publication.
If modification has been made since then, difference may exist between the content of this
manual and the actual vehicle.
* Illustrations in this manual are used to show the
basic principles of operation and work procedures.
They may not represent the actual vehicle exactly
in detail.
* This manual is intended for those who have
enough knowledge and skills for servicing
HYOSUNG vehicles. Without such knowledge and
skills, you should not attempt servicing by relying
on this manual only.
Instead, please contact your nearby authorized
HYOSUNG motorcycle dealer.

GROUP INDEX
GENERAL INFORMATION

PERIODIC MAINTENANCE

ENGINE

FUEL SYSTEM

ELECTRICAL SYSTEM

CHASSIS

SERVICING INFORMATION

HYOSUNG MOTORS & MACHINERY INC.

COPYRIGHT HYOSUNG MOTORS & MACHINERY INC. 1999

HOW TO USE THIS MANUAL

TO LOCATE WHAT YOU ARE
LOOKING FOR:
1. The text of this manual is divided into sections.
2. As the title of these sections are listed on the previous
page as GROUP INDEX, select the section where what
you are looking for belong.
3. Holding the manual as shown at the right will allow you to find
the first page of the section easily.
4. On the first page of each section, its contents are listed. Find
the item and page you need.

COMPONENT PARTS
Example: Rear wheel/Rear brake

SYMBOL
Listed in the table below are the symbols indicating instructions and other information necessary for servicing and
meaning associated with them respectively.
SYMBOL

DEFINITION

SYMBOL

DEFINITION

Torque control required.

Data beside it indicates
specified torque.

Apply THREAD LOCK1324.

Apply oil. Use engine oil unless

otherwise specified.

Apply or use brake fluid.

Apply SUPER GREASEA.

Measure in voltage range.

Apply SUPER GREASEC.

Measure in resistance range.

Apply SILICONE GREASE.

Measure in current range.

Apply MOLY PASTE.

Use special tool.

Apply BOND1215.

GENERAL INFORMATION

1
CONTENTS
INFORMATION LABELS

1-1

GENERAL PRECAUTIONS

1-1

SERIAL NUMBER LOCATION

1-3

FUEL AND OIL RECOMMENDATIONS

1-3

BREAK-IN PROCEDURES

1-4

EXTERIOR ILLUSTRATION

1-5

SPECIFICATIONS

1-6

1-1 GENERAL INFORMATION

WARNING / CAUTION / NOTE

Please read this manual and follow its instructions carefully. To emphasize special information, the symbol and
the words WARNING, CAUTION and NOTE have special meanings. Pay special attention to the messages
highlighted by these signal words.
WARNING

Indicates a potential hazard that could result in death or injury.

CAUTION

Indicates a potential hazard that could result in vehicle damage.

NOTE:
Indicates special information to make maintenance easier or instructions cleaner.
Please note, however, that the warning and cautions contained in this manual cannot possibly cover all potential
hazards relating to the servicing, or lack of servicing, of the motorcycle. In addition to the WARNING and CAUTION
stated, you must use good judgement and basic mechanical safety principles. If you are unsure about how to perform a
particular service operation, ask a more experienced mechanic for advice.

GENERAL PRECAUTIONS
WARNING

Proper service and repair procedures are important for the safety of the service machanic and the safety
and reliability of the vehicle.
When 2 or more persons work together, pay attention to the safety of each other.
When it is necessary to run the engine indoors, make sure that exhaust gas is forced outdoors.
When working with toxic or flammable materials, make sure that the area you work in is wellventilated
and that you follow all off the material manufacturers instructions.
Never use gasoline as a cleaning solvent.
To avoid getting burned, do not touch the engine, engine oil or exhaust system during or for a while
after engine operation.
After servicing fuel, oil, exhaust or brake systems, check all lines and fittings related to the system for
leaks.

GENERAL INFORMATION 1-2

CAUTION

If parts replacement is necessary, replace the parts with HYOSUNG Genuine Parts or their equivalent.
When removing parts that are to be reused, keep them arranged in an orderly manner so that they may be
reinstalled in the proper order and orientation.
Be sure to use special tools when instructed.
Make sure that all parts used in reassembly are clean, and also lubricated when specified.
When use of a certain type of lubricant, bond, or sealant is specified, be sure to use the specified type.
When removing the battery, disconnect the negative cable first and then positive cable. When reconnecting the battery, connect the positive cable first and then negative cable, and replace the terminal cover on the
positive terminal.
When performing service to electrical parts, if the service procedures do not require use of battery power, diconnect the negative cable at the battery.
Tighten cylinder head and case bolts and nuts, beginning with larger diameter and ending with smaller
diameter, from inside to outside diagonally, to the specified tightening torque.
Whenever you remove oil seals, gaskets, packing, O-rings, locking washers, cotter pins, circlips, and
certain other parts as specified, be sure to replace them with new ones. Also, before installing these new
parts, be sure to remove any left over material from the mating surfaces.
Never reuse a circlip. When installing a new circlip, take care not to expand the end gap larger than
required to slip the circlip over the shaft. After installing a circlip, always ensure that it is completely seated in its groove and securely fitted.
Do not use self-locking nuts a few times over.
Use a torque wrench to tighten fasteners to the torque values when specified. Wipe off grease or oil
if a thread is smeared with them.
After reassembly, check parts for tightness and operation.

To protect environment, do not unlawfully dispose of used motor oil and other fluids: batteries, and tires.
To protect Earths natural resouces, properly dispose of used vehicles and parts.

1-3 GENERAL INFORMATION

HYOSUNG PRIMA (SF - 50)

RIGHT SIDE

LEFT SIDE

* Difference between photographs and actual motorcycles depends on the markets.

SERIAL NUMBER LOCATION

The frame serial number or V.I.N. (Vehicle Identification Number) is stamped on the right side of the frame under the
footboard. The engine serial number is located on the up side of the crankcase assembly.
These numbers are required especially for registering the machine and ordering spare parts.

FUEL AND OIL RECOMMENDATION

FUEL
Gasoline used should be graded 85-95 octane (Research Method) or higher. An unleaded gasoline type is
recommended.

TRANSMISSION OIL
Make sure that the transmission oil you use comes under API
classification of SH, SG or SF and that its viscosity rating
is SAE 10W/30 or 10W/40. If an SAE 10W/30 or 10W/40 motor
oil is not available, select an alternate according to the right chart.

GENERAL INFORMATION 1-4

ENGINE OIL
Specification and classification: APOLLOIL BIKE-K, HYPOL HS

BRAKE FLUID
Specification and classification: DOT4

WARNING

Since the brake system of this motorcycle is filled with a glycol-based brake fluid by the manufacturer, do not
use or mix different types of fluid such as silicone-based and petroleum-based fluid for refilling the system, otherwise serious damage will result.
Do not use any brake fluid taken from old or used or unsealed containers.
Never re-use brake fluid left over from a previous servicing, which has been stored for a long period.

FRONT FORK OIL

Use fork oil : TELLUS #37

BREAK-IN PROCEDURES
During manufacture only the best possible materials are used and all machined parts are finished to a very high
standard but it is still necessary to allow the moving parts toBREAK-INbefore subjecting the engine to maximum
stresses. The future performance and reliability of the engine depends on the care and restraint exercised during its
early life. The general rules are as follows:
Keep to these break-in engine speed limits:
Up to 1,000km(600miles): Less than 1/2 throttle.
Upon reaching an odometer reading of 1,000 km you can subject the motorcycle to full throttle operation.
Do not maintain constant engine speed for an extended period during any portion of the break-in. Try to vary the
throttle position.

1-5 GENERAL INFORMATION

125

740

990

1,110

320

350
635

EXTERIOR ILLUSTRATION

1,270
1,825

135

Tail/Brake lamp

710

535
690

(Front) Turnsignal
lamp

600

Rear reflector
(Rear) Turnsignal
lamp

Head lamp

GENERAL INFORMATION 1-6

SPECIFICATIONS
DIMENSIONS AND DRY MASS
Overall length
Overall width
Overall height
Wheelbase
Ground clearance
Dry mass

1,825 mm (71.9 in)

635 mm (25.0 in)
1,110 mm (43.7 in)
1,270 mm (50.0 in)
125 mm (4.9 in)
88 kg (194 lbs)

ENGINE
Type
Number of cylinder
Bore
Stroke
Piston displacement
Carburetor
Air cleaner
Starter system
Corrected compression ratio
Intake system

Two-stroke, forced air cooled

1
41 mm (1.6 in)
37.4 mm (1.5 in)
49 (3.0 cu.in)
SIDE DRAFT VARIABLE VENTURI (PISTON)
Wet filter type
Kick/self starter
7.4 : 1
Reed valve

TRANSMISSION
Clutch
Reduction ratio
Drive system

Dry shoe, automatic, centrifugal type

2.997~0.813
V-belt drive

CHASSIS
Front suspension
Rear suspension
Caster
Trail
Steering angle
Front tire size
Rear tire size
Front brake
Rear brake

Telescopic type
Coil spring type
25
75mm (2.95in)
45(right & left)
110/70-12 47J
120/70-12 51J
Disc
Drum

1-7 GENERAL INFORMATION

ELECTRICAL
Ignition type
Ignition timing
Spark plug
Battery
Generator
Fuse
Headlamp
Turn signal lamp
Tail/Brake lamp
Speedometer lamp
Oil level indicator lamp
Turn signal indicator lamp

CDItype
20B.T.D.C. at 1,000 rpm
BR8HSA
12V 3Ah/10HR
Magneto
10A
15W2
10W4
5/10W
1.7W2
1.7W
1.7W

CAPACITIES
Fuel tank
Engine oil tank
Transmission oil

NOTE:
The specifications are subject to change without notice.

4.8
1.0
110cc (Replace)
130cc (Overhaul)

PERIODIC MAINTENANCE

CONTENTS
PERIODIC MAINTENANCE SCHEDULE

2- 1

MAINTENANCE PROCEDURES

2- 3

BATTERY

2- 3

CYLINDER HEAD NUTS AND EXHAUST PIPE NUTS

2- 4

CYLINDER HEAD AND CYLINDER

2- 4

SPARK PLUG

2- 4

FUEL LINE

2- 5

AIR CLEANER ELEMENT

2- 5

THROTTLE CABLE PLAY

2- 6

ENGINE IDLE SPEED

2- 7

OIL PUMP

2- 7

TRANSMISSION OIL

2- 8

BRAKES

2- 8

TIRES

2-10

STEERING

2-11

FRONT SUSPENSION

2-11

REAR SUSPENSION

2-12

CHASSIS AND ENGINE MOUNTING BOLTS AND NUTS

2-12

2-1 PERIODIC MAINTENANCE

PERIODIC MAINTENANCE SCHEDULE

The chart below lists the recommended intervals for all the required periodic service work necessary to keep the
motorcycle operating at peak performance and economy.
NOTE:
More frequent servicing should be performed on motorcycles that are used under severe conditions.

PERIODIC MAINTENANCE CHART

ENGINE
Interval

Initial 1,000 km

Every 4,000 km

Every 8,000 km

page

Battery

Inspect

Inspect

2-3

Cylinder head nuts

exhaust pipe nuts

Inspect

Inspect

2-4

Clean

2-4

Clean

Clean

Replace

2-4

Inspect

Inspect

Item

Cylinder head, cylinder.

Spark plug
Fuel line

Replace every 4 years

Air cleaner element

2-5
2-5

Clean every 3,000 km

Throttle cable play

Inspect

Inspect

2-6

Engine idle speed

Inspect

Inspect

2-7

Oil pump

Inspect

Inspect

2-7

Transmission oil

Inspect

Inspect

2-8

Initial 1,000 km

Every 4,000 km

Every 8,000 km

page

Inspect

Inspect

2-9

Inspect

Inspect

CHASSIS
Interval
Item
Brakes
Brake hose

Replace every 4 years

Brake fluid

Inspect

Inspect

Replace every 2 years

2-9
2-9

Tires

Inspect

Inspect

2-10

Steering

Inspect

Inspect

2-11

Front suspension

Inspect

Inspect

2-11

Rear suspension

Inspect

Inspect

2-12

Chassis bolts and nuts

Inspect

Inspect

2-12

PERIODIC MAINTENANCE 2-2

LUBRICATION CHART
The maintenance schedule, which follows, is based on this philosophy. It is timed by odometer indication, and is
calculated to achieve the ultimate goal of motorcycle maintenance in the most economical manner.
Interval

Initial and Every 4,000 km

Every 8,000 km

Motor oil

Throttle grip

Grease

Brake cable

Motor oil

Speedometer cable

Grease

Speedometer gear box

Grease

Brake cam

Grease

Item
Throttle cable

Steering stem bearing

Grease every 2 years or 20,000 km

WARNING

Be careful not to apply too much grease into the brake cam. If grease is on the linings, brake slippage will
result.
Lubricate exposed parts which are subject to rust, with either motor oil or grease whenever the motorcycle has
been operated under wet or rainy conditions.
Before lubricating each part, clean off rusty sports and wipe off grease, oil, dirt or grime.

2-3 MAINTENANCE PROCEDURE

MAINTENANCE PROCEDURE
This section describes the service procedures for
each section of the periodic maintenance.

BATTERY
NOTE:
Inspect Initial 1,000 km and Every 4,000 km.
Remove the pillion seat for measure of battery voltage.
Remove the battery lead and then lead at the
battery terminls and remove the battery.
Using pocket tester, measure the battery voltage.
If the tester reading is less than 12.0V, recharge
the battery with a battery charger. (Refer to page 5-13)
Pocket tester : 09900-25002
Bettery voltage

Minimum 12.0V
Recharge

Standard charge

0.4A5~10 Hours

Fast charge

4A30 Minutes

CAUTION

W h e n r e c h a r g i n g t h e b a t t e r y r e m o v e
the battery from motorcycle.
Otherwise, regulator/rectifier unit
should be an obstacle.
W h e n r e c h a r g i n g t h e b a t t e r y , d o n o t
remove the caps.
When recharging the battery, above the
charge electric current and time should
be kept as 12V.

MAINTENANCE PROCEDURE 2-4

CYLINDER HEAD NUTS AND EXHAUST

PIPE NUTS
NOTE:
Inspect Initial 1,000 km and Every 4,000 km.

CYLINDER HEAD NUTS

Remove the personal trunk.
Remove the spark plug cap.
Remove the cylinder head cover bolt.
(Refer to page 3-5)
Tighten the four nuts to the specified torque with a
torque wrench, when engine is cold.
Cylinder head nut : 8~12 Nm (0.8~1.2 kgm)

EXHAUST PIPE NUTS

Tighten the exhaust pipe nuts to the specified
torque.
Exhaust pipe nuts : 8~12 Nm (0.8~1.2 kgm)

CYLINDER HEAD AND CYLINDER

NOTE:
Remove carbon Every 8,000km.
Carbon deposits in the combustion chamber and the
cylinder head will raise the compression ratio and may
cause preignition or overheating. Carbon deposited at
the exhaust port of the cylinder will prevent the flow of
exhaust gases, reducing the output. Remove carbon
deposits periodically.

SPARK PLUG
NOTE:
Inspect Initial 1,000km and Every 4,000km,
Replace every 8,000km.
Neglecting the spark pulg maintenance eventually leads to
difficult starting and poor performance. If the spark plug is
used for a long period, the electrode gradually burns away
and carbon builds up along the inside part. In accordance
with the Periodic Inspection Chart, the plug should be
removed for inspection, cleaning and to reset the gap.
Carbon deposits on the spark plug will prevent good
sparking and cause misfiring. Clean the deposits off
periodically.

Carbon

2-5 MAINTENANCE PROCEDURE

If the center electrode is fairly worn down, the plug

should be replaced and the plug gap set to the specified gap using a thickness gauge.
Thickness gauge : 09900-20804
Spark plug gap

0.6 ~ 0.7 mm

Check the spark plug for burnt condition. If abnormal,

replace the plug as indicated in the chart.
TYPE

SPARK PLUG SPECIFICATION

Standard

BR8HSA

Tighten the spark plug to the specification.

Spark plug : 25~30 Nm (2.5~3.0 kgm)
CAUTION

To check the spark plug, first make sure that

the fuel used is unleaded gasoline, and if plug
is either sooty with carbon or burnt white,
replace it.
Confirm the thread size and reach when replacing the plug.

FUEL LINE
NOTE:
Inspect Initial 1,000 km and Every 4,000 km,
Replace every four years.
Inspect leakage of the fuel line and connection part.
If abnormal, replace it.

AIR CLEANER ELEMENT

NOTE:
Clean Every 3,000km and Replace Every 12,000km.
If the air cleaner is clogged with dust, intake resistance
will be increased with a resultant decrease in power output and an increase in fuel consumption. Check and
clean the element in the following manner.
Remove the air cleaner cover by removing the eight
screw.

MAINTENANCE PROCEDURE 2-6

Remove the air cleaner cover, separate the element.

Fill a washing pan of a proper size with non-flammable

cleaning solvent. Immerse the element in the cleaning
solvent and wash them clean.
Squeeze the cleaning solvent out of the washed element by pressing it between the palms of both hands:
do not twist or wiring the element or if will develop
tears.
Immerse the element in Hyosung genuine oil, and
squeeze the oil out of the element leaving it slightly
wet with oil.
Fit the elements to the cleaner case properly.

Inside

CAUTION

Before and during the cleaning operation,

inspect the element for tears. A torn element
must be replaced.
Be sure to position the element snugly and correctly, so that no incoming air will bypass it.
Remember, rapid wear of piston rings and
cylinder bore is often caused by a defective or
poorly fitted element.

Non-flammable
cleaning solvent

Hyosung
genuine oil

THROTTLE CABLE PLAY

NOTE:
Inspect Initial 1,000 km and Every 4,000 km.
Loosen the lock nut and adjust the cable play
by turning adjuster in or out to obtain the following
cable play. After adjusting play, tighten the lock nut.
Throttle cable play

0.5 ~ 1.0 mm

2-7 MAINTENANCE PROCEDURE

ENGINE IDLE SPEED

NOTE:
Inspect Initial 1,000 km and Every 4,000 km.
CAUTION

Make this adjustment when the engine is hot.

start up the engine and set its speed at anywhere

between 1,750 and 1,850 rpm by turning the throttle
stop screw .
Engine idle speed

1,800 50 rpm

Engine tachometer : 09900-26006

Fixing

OIL PUMP
NOTE:
Inspect Initial 1,000 km and Every 4,000 km.
The engine oil is fed by the oil pump to the engine. The
amount of oil fed to it is regulated by engine speed and
oil pump control lever which is controlled by amount of
throttle opening.
Check the oil pump in the following manner to confirm
correct operation for throttle valve full closing position.
Fix the throttle grip. (The early idling condition)
Check whether the mark on the oil pump control
lever is aligned with the index mark when the
throttle grip is fixed as above.
If the marks are not aligned, loosen lock nuts and
turn the adjuster in or out to align the marks.
After aligning the marks, tighten the lock nuts .

CAUTION

Oil pump cable adjustment must be done after

throttle cable adjustment.

MAINTENANCE PROCEDURE 2-8

TRANSMISSION OIL
NOTE:
Inspect Initial 1,000 km and Every 8,000 km.
Inspect transmission oil periodically following procedure
below.
Remove the low leg shield.
Remove the clutch cover.(Refer to page 3-6)

Remove the oil level bolt and inspect oil level.

If the level is below the level hole, add oil until oil
flows from the level hole.
Tighten the oil level bolt to the specified torque.
Oil level bolt : 9~15 Nm (0.9~1.5 kgm)

Oil drain plug

BRAKES
NOTE:
Inspect Initial 1,000 km and Every 4,000 km.
Replace the hose Every four years.
Replace the brake fluid Every two years.

Middle line

FRONT BRAKE FLUID LEVEL

Keep the motorcycle upright and place the handlebar
straight.
Check brake fluid level by observing the middle line
on the brake fluid reservoir.
When the level is bolow the middle line, replenish
with brake fluid that meets the following specification.
Specification and classification

DOT4
WARNING

HYOSUNG Brake fluid : 99000-23021

WARNING

The brake system of this motorcycle is filled with

a glycolbased brake fluid. Do not use or mix different type of fluid such as silicone-based and
petroleum-based. Do not use any brake fluid
taken from old, used or unsealed containners.
Never re-use the brake fluid left over from the last
servicing and stored for long periods.

Brake fluid, if it leaks, will interfere with safe running and immediately discolor painted surfaces.
Check the brake hoses for cracks and hose joints
for leakage before riding.

2-9 MAINTENANCE PROCEDURE

BRAKE PADS
Wearing condition of brake pads can be checked by
observing the limit line marked on the pad. When the
wear exceeds the limit mark, replace the pads with new
ones.
BRAKE LAMP SWITCH
For the brake lamp come on after the brake lever is
pulled, adjust the brake lamp switch.

BLEEDING AIR FROM THE BRAKE FLUID CIRCUIT

Air trapped in the fluid circuit acts like a cushion to
absorb a large proportion of the pressure developed by
the master cylinder and thus interferes with the full braking performance of the brake caliper. The presence of
air is indicated bysponginessof the brake lever and
also by lack of braking force. Considering the danger to
which such trapped air exposes the machine and rider,
it is essential that, after remounting the brake and
restoring the brake system to the normal condition, the
brake fluid circuit be purged of air in the following manner:
Fill up the master cylinder reservoir to the upper end
of the inspection window. Replace the reservoir cap
to prevent entry of dirt.
Attach a pipe to the caliper bleeder valve, and insert
the free end of the pipe into a receptacle.
Bleeder valve : 6~9 Nm (0.6~0.9 kgm)
Bleed air from the bleeder valve.
Squeeze and release the brake lever several times in
rapid succession, and squeeze the lever fully without
releasing it. Loosen the bleeder valve by turning it a
quarter of a turn so that the brake fluid runs into the
receptacle: this will remove the tension of the brake
lever causing it to touch the handlebar grip. Then,
close the valve, pump and squeeze the lever, and
open the valve. Repeat this process until the fluid
flowing into the receptacle no longer contains air bubbles.
CAUTION

Replenish the brake fluid reservoir as necessary

while bleeding the brake system.
Make sure that there is always some fluid visible
in the reservoir.
Close the bleeder valve, and disconnect the pipe. Fill
the reservoir to the upper end of the inspection window.

Do original position

Turning
Turning
Turning

MAINTENANCE PROCEDURE 2-10

15~25 mm

WARNING

Handle the brake fluid with care: the fluid reacts

chemically with paint, plastics, rubber materials, etc.

REAR BRAKE
Adjust by turning the adjusting nut so that the play
is 15~25 mm as shown in the illustration.

Range

in

Play
is had
much

Brake lining wear limit

This motorcycle is equipped with the brake lining wear
limit indicator on the rear brake. As shown in the illustration at right, at the condition of normal lining wear, an
extended line from the index mark on the brake
camshaft should be within the range embossed on the
crankcase LH. To check wear of the brake lining, follow
the steps below.
First check if the brake system is properly adjusted.
While operating the brake, check to see that the
extension line from the index mark is within the range
on the brake panel.
If the index mark is outside the range as shown in the
illustration at right, the brake shoe assembly should
be replaced to ensure safe operation.

Play
is
had

little

Adjuster
nut

Front
Index mark

Brake lining wear limit

The extension line of the index mark is within the range.

Front
Index mark
Brake lining wear limit

The extension line of the index mark is outside of the range.

TIRES
NOTE:
Inspect Initial 1,000 km and Every 4,000 km.
TIRE PRESSURE
If the tire pressure is too high, the motorcycle will tend to
ride stiffly and have poor traction. Conversely, if the tire
pressure is too low, stability will be adversely affected.
Therefore, maintain the correct tire pressure for good
roadability and to prolong tire life.

2-11 MAINTENANCE PROCEDURE

CAUTION

The standard tire fitted on this motorcycle is

110/70-12 47J for front and 120/70-12 51J for rear.
The use of a tire other than the standard may
cause handling instability. It is highly recommended to use a HYOSUNG Genuine Tire.
COLD INFLATION
TIRE PRESSURE

NORMAL RIDING
SOLO RIDING

DUAL RIDING

kpa

kg/

kpa

kg/

FRONT

123

1.25

172

1.75

REAR

196

2.00

221

2.25

TIRE TREAD CONDITION

Operating the motorcycle with the excessively worn tires
will decrease riding stability and consequently invite a
dangerous situation. It is highly recommended to
replace the tire when the remaining depth of tire tread
reaches the following specification.
TREAD DEPTH SERVICE LIMIT
FRONT

1.6 mm

REAR

1.6 mm

STEERING
NOTE:
Inspect Initial 1,000 km and Every 4,000 km.
Steering should be adjusted properly for smooth turning
of handlebars and safe running. Too stiff steering prevents smooth turning of handlebars and too loose steering will cause poor stability.
Check that there is no play in the front fork assembly by
supporting the machine so that the front wheel is off the
ground, with wheel straight ahead, grasp lower shock
absorber near the axle and pull forward. If play is
found, perform steering bearing adjustment.(Refer to
page 6-21)

FRONT SUSPENSION
NOTE:
Inspect Initial 1,000 km and Every 8,000 km.
Inspect the front shock absorber for oil leakage or other
damage, and replace the defective parts, if necessary.

OVER

NORMAL

SHORT

MAINTENANCE PROCEDURE 2-12

REAR SUSPENSION
NOTE:
Inspect Initial 1,000 km and Every 8,000 km.
Inspect the rear shock absorber for oil leak and the
mounting rubbers including engine mountings for wear
and damage. Replace the defective part if necessary.

CHASSIS AND ENGINE MOUNTING BOLTS AND NUTS

NOTE:
Inspect Initial 1,000 km and Every 4,000 km.
These bolts and nuts listed below are important safety parts. They must be loosened first and retightened, to the specified
torque with a torque wrench.
Front axle nut() : 33~52 Nm (3.3~5.2 kgm)
Steering stem lock nut () : 60~100 Nm (6.0~10.0 kgm)
Handlebar clamp nut() : 48~52 Nm (4.8~5.2 kgm)
Handlebar set bolt() : 22~28 Nm (2.2~2.8 kgm)
Front brake master cylinder bolt() : 8~12 Nm (0.8~1.2 kgm)
Front brake hose union bolt() : 20~25 Nm (2.0~2.5 kgm)
Front brake caliper mounting bolt() : 18~28 Nm (1.8~2.8 kgm)
Front brake air bleeder valve() : 6~9 Nm (0.6~0.9 kgm)
Rear axle nut() : 60~90 Nm (6.0~9.0 kgm)
Rear shock absorber bolt(upper and lower)() : 22~35 Nm (2.2~3.5 kgm)
Rear brake cam lever nut() : 6~9 Nm (0.6~0.9 kgm)
Engine mounting bracket bolt() : 48~72 Nm (4.8~7.2 kgm)
Engine mounting bolt() : 40~60 Nm (4.0~6.0 kgm)

2-13 MAINTENANCE PROCEDURE

ENGINE

CONTENTS
ENGINE REMOVAL AND REMOUNTING

3- 1

ENGINE REMOVAL

3- 1

ENGINE REMOUNTING

3- 3

ENGINE DISASSEMBLY

3- 4

ENGINE COMPONENTS INSPECTION AND SERVICING

3-14

BEARINGS

3-14

OIL SEALS

3-14

CRANKSHAFT

3-15

AUTOMATIC CLUTCH INSPECTION

3-15

CYLINDER HEAD

3-18

CYLINDER

3-19

PISTON

3-19

REED VALVE

3-22

ENGINE REASSEMBLY

3-22

OIL SEALS

3-22

BEARINGS

3-23

BUSHINGS

3-23

CRANKSHAFT

3-24

CRANKCASE

3-25

CENTER STAND

3-26

REAR AXLE SHAFT, BRAKE AND WHEEL

3-27

TRANSMISSION

3-29

STARTER DRIVEN GEAR AND STARTING MOTOR

3-31

MOVABLE DRIVEN AND CLUTCH

3-32

MOVABLE DRIVE

3-36

KICK STARTER

3-38

PISTON

3-40

OIL PUMP AND INTAKE PIPE

3-42

MAGNETO

3-43

MUFFLER

3-45

3-1 ENGINE

ENGINE REMOVAL AND

REMOUNTING
ENGINE REMOVAL

Before taking the engine out of the frame, thoroughly

clean the engine with a suitable cleaner. The procedure
of engine removal is sequentially explained as follows.
Remove the low leg shield.
Remove the air cleaner by removing the mounting
bolts and clamp screw .

Disconnect the ignition coil lead wires and spark plug

cap.

Disconnect the oil pump cable and the thermoelement lead coupler .
Disconnect the throttle cable. (Refer to page 4-2)

Disconnect the vacuum hose , fuel hose and oil

hose .

ENGINE 3-2

Disconnect the magneto lead wire and starting

moter lead wire .

Remove the rear brake cable by removing the bolt

, bolt and adjuster nut .

Remove the rear shock absorber mounting lower

bolt.

3-3 ENGINE

Remove the engine mounting shaft and remove the

engine from the frame.

ENGINE REMOUNTING
The engine can be mounted in the reverse order of
removal.
Install the damper to the crankcase bracket as shown
in the illustration.
WithUPmark faced upward, install the crankcase
bracket on the frame. Do not tighten the bracket
bolt at this stage. Pull up on the rear part of
crankcase bracket and while holding it, tighten the
bracket bolt to specification. Tighten both the rear
shock absorber bolt and engine mounting bolt
to specification.

UPmark

Front side

10mm
8mm

Damper

Engine mounting bracket bolt

: 48~72 Nm (4.8~7.2 kgm)
Engine mounting bolt
: 40~60 Nm (4.0~6.0 kgm)
Rear shock absorber bolt
: 22~35 Nm (2.2~3.5 kgm)

ENGINE 3-4

Install the magneto lead wire and starting motor

lead wire correctly.

After remounting the engine, route the wiring harness

properly and following adjustments are necessary.
Page
Throttle cable play
2-6
Idling adjustment
2-7
Oil pump cable paly
2-7
Rear brake cable adjustment
2-10
Air bleeding at oil pump
4-9

ENGINE DISASSEMBLY
MUFFLER
Remove the muffler by removing the nuts.

MAGNETO
Remove the cooling fan.
Remove the magneto rotor nut with the special
tool.
Rotor holder : 09930-40113

3-5 ENGINE

Remove the magneto rotor with the special tool.

Rotor remover : 09930-30163
Rotor remover sliding shaft : 09930-30102
Remove the magneto stator and key.

REED VALVE
Remove the intake pipe with reed valve .

OIL PUMP
Remove the oil pump .
Remove the oil pump driven gear .

CYLINDER
Remove the cylinder cowling.
Remove the cylinder head and cylinder .

ENGINE 3-6

PISTON
Place a cloth beneath the piston and remove the piston circlip with a long nose pliers.
Remove the piston pin and piston .
Remove the piston pin bearing .

KICK STARTER
Remove the kick starter lever .
Remove the clutch cover .

Remove the kick starter shaft spring and kick

starter shaft .

KICK STARTER DRIVEN GEAR

Remove the E-ring with the long nose plier.
Remove the spacer , spring and kick starter
driven gear .

3-7 ENGINE

MOVABLE DRIVE FACE

Remove the kick starter driven nut with the special
tool.
CAUTION

This nut has left-hand thread.

Conrod holder : 09910-20115

Remove the fixed drive face and V-belt .

Disassemble the movable drive face .

STARTER DRIVEN GEAR

Remove the starter driven gear .

MOVABLE DRIVEN FACE

Remove the clutch housing with the special tool.
Rotor holder : 09930-40113

ENGINE 3-8

Loosen the clutch shoe nut with the special tool.

Rotor holder : 09930-40113

Remove the nut while holding down the clutch shoe

assembly by both hands as shown in the illustration.
WARNING

Gradually back off the clutch shoe assembly

pressed down by hand to counter the clutch
spring load. Releasing the hand suddenly may
cause the parts to fly apart.
Remove the nut .
Remove the clutch shoe assembly .
Remove the spring .

;;
;;
;;
;;
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;;
;;;;

CAUTION

Do not attempt to diassemble the clutch shoe

assembly.
It is not serviceable.

Using a thin blade screwdriver or the like, pry up the

movable driven face spring guide .

Remove the pins , movable driven face and

fixed driven face .

3-9 ENGINE

Remove the roller bearing with the special tools.

Bearing remover( 17 mm) : 09923-73210
Rotor remover sliding shaft : 09930-30102

CAUTION

The removed bearing should be replaced with a

new one.

Remove the circlip .

Remove the bearing with the special tool.

Wheel bearing remover : 09941-50111
CAUTION

The removed bearing should be replaced with a

new one.

TRANSMISSION
Drain transmission oil.
Remove the gear box cover .
Remove the driveshaft .

ENGINE 3-10

Remove the oil seal from the gear box cover with
the special tool.
Oil seal remover : 09913-50121
CAUTION

The removed oil seal should be replaced with a

new one.

Remove the bearing with the special tool.

Bearing installer : 09913-76010
CAUTION

The removed bearing should be replaced with a

new one.

Remove the circlip and final driven gear .

Remove the idle shaft .

Remove the drive shaft bearing .

Rotor remover sliding shaft : 09930-30102
Bearing remover ( 12 mm) : 09921-20210

3-11 ENGINE

WHEEL, BRAKE
Remove the rear axle nut and washer .
Remove the rear wheel .

Remove the brake shoes and rear axle shaft .

Remove the bearing retainer .

Remove the bearing with the special tool.

Bearing installer : 09913-75820

ENGINE 3-12

Remove the oil seal with the special tool.

Oil seal remover : 09913-50121

CENTER STAND
Remove the return spring .

Remove the cotter pin , washer and shaft .

Remove the center stand .

CRANKCASE
Remove the crankcase securing screws.
CAUTION

Loosen the crankcase screws diagonally.

Crankcase separater : 09920-13120

3-13 ENGINE

Remove the crankshaft with the special tool.

Crankcase separater : 09920-13120

Remove the bearings, oil seals and bushings.

ENGINE 3-14

Using two steel tubes of appropriate size, press out

the engine mounting bushings on a vise as shown in
the illustration.

Bushing

Front side

Rear side

Bushing
Bushing
Crankcase

ENGINE COMPONENTS
INSPECTION AND SERVICING
BEARINGS
Wash the bearing with cleaning solvent and lubricate
with motor oil before inspecting.
Turn the inner ring and check to see that the inner ring
turns smoothly. If it does not turn lightly, quietly and
smoothly, or if noise is heard, the bearing is defective
and must be replaced with a new one.

OIL SEAL
Damage to the lip of the oil seal may result in leakage of
the fuel-air mixture or oil. Inspect for damage and be
sure to replace the damaged seal if found.

Crankcase

3-15 ENGINE

CRANKSHAFT
CRANKSHAFT RUNOUT
Support crankshaft byVblocks, with the dial gauge
rigged to read the runout as shown.
Crankshaft runout

Service limit 0.08 mm

Excessive crankshaft runout is often responsible for

abnormal engine vibration. Such vibration shortens
engine life.
V-block(100 mm) : 09900-21304
Magnetic stand : 09900-20701
Dial gauge(1/100 mm) : 09900-20606
WEAR AND CLEARANCE OF CONROD BIG END
Turn the crankshaft with the conrod to feel the smoothness of rotary motion in the big end. Move the rod up
and down while holding the crankshaft rigidly to be sure
that there is no rattle in the big end.
Wear on the big end of the conrod can be estimated by
checking the movement of the small end of the rod. This
method can also check the extent of wear on the parts
of the conrods big end.
If wear exceeds the limit, conrod, crank pin and crank
pin bearing should all be replaced.
Conrod big end runout

Service limit 3.0 mm

CONROD SMALL END BORE I.D.

Measure the conrod small end diameter with a caliper
gauge.
Conrod small end bore I.D.

Service limit 14.047 mm

Dial calipers : 09900-20605

AUTOMATIC CLUTCH INSPECTION

This motorcycle is equipped with an automatic clutch
and variable ratio belt drive transmission. The engagement of the clutch is governed by engine RPMs and
centrifugal mechanism located in the clutch.
To insure proper performance and longevity of the
clutch assembly it is essential that the clutch engages
smoothly and gradually. Two inspection checks must be
performed to thoroughly check the operation of the drivetrain. Follow the procedures listed.

ENGINE 3-16

1. CLUTCH-IN INSPECTION
Warm up the motorcycle to normal operating temperature.
Remove the right frame side cover.
Connect an engine tachometer to the engine.
Seated on the motorcycle with the motorcycle on level
ground, increase the engine RPMs slowly and note the
RPM at which the motorcycle begins to move forward.
Engine tachometer : 09900-26006
Clutch-in RPM

Standard

3,600 rpm

Tolerance

200 rpm

2. CLUTCH TIGHT INSPECTION

Grip the front and rear brake lever fully, and measure
the engine RPM when open the throttle.
Warm the engine to normal operating temperatures.
Connect an engine tachometer to the engine.
Apply the rear brake as firm as possible.
Briefly open the throttle fully and note the maximum
engine RPMs sustained during the test cycle.
CAUTION

Do not apply full power for more than 3 seconds

or damage to the clutch or engine may occur.

Clutch tight RPM

Standard

6,000 rpm

Tolerance

200 rpm

If the engine RPM does not coincide with the specified

RPM range, then disassemble the clutch.
Clutch shoe - inspect the shoes visually for chips, cracking, uneven wear and burning, and check the thickness of
the shoes with the vernier calipers. If the thickness is less
than the following service limit, replace them as a set.
Clutch springs - visually inspect the clutch springs for
stretched coils or broken coils.
Clutch shoe thickness

Service limit 2.0 mm

3-17 ENGINE

CAUTION

Clutch shoes or springs must be changed as a

set and never individually.
Clutch housing inspect visually the condition of the
inner clutch housing surface for scrolling, cracks, or
uneven wear. Measure inside diameter of the clutch
wheel with inside calipers. Measure the diameter at several points to check for an in-of-round condition as well
as wear.
Clutch housing I.D.

Service limit 110.35 mm

DRIVE V-BELT
Remove the drive V-belt and check for cracks, wear and
separation. Measure the drive V-belt width with a vernier
calipers. Replace it if the drive V-belt width is less than
the service limit or any defect has been found.
Drive V-belt width

Service limit 15.3 mm

CAUTION

Always keep the drive belt away from any greasy

mater.

DRIVE FACE
Inspect the V-belt contact surface of the drive faces for
wear, scratches or any abnormality. If there is something unusual, replace the drive face with a new one.

ROLLER AND MOVABLE DRIVE SURFACE

Inspect each roller and movable drive surface for wear
or damage.

ENGINE 3-18

MOVABLE DRIVEN SPRING

Measure the free length of the movable driven spring. If
the length is shorter than the service limit, replace the
spring with a new one.
Movable driven spring free length Service limit 135~153 mm

MOVABLE DRIVEN FACE PIN AND OIL SEAL

Turn the movable driven faces and check to see that the
movable driven faces turn smoothly.
If not rotate smoothly, visually inspect the lip of oil seal,
movable driven face sliding surface and sliding pins for
wear or damage.

MOVABLE DRIVEN FACE

Inspect the V-belt contacting surface of both driven
faces for any scratches, wear and damage.
Replace the movable driven face with new one if there
are any abnormality.

CYLINDER HEAD
Decarbon the combustion chamber.
Check the gasketed surface of the cylinder head for distortion with a straightedge and thickness gauge, taking a
clearance reading at several places.
Thickness gauge : 09900-20806
Cylinder head distortion

Service limit 0.1 mm

3-19 ENGINE

If the largest reading at any portion of the straightedge

exceeds the limit, rework the surface by rubbing it
against emery paper (of about # 400) laid flat on the surface plate in a lapping manner. The gasketed surface
must be smooth and perfectly flat in order to secure a
tight joint: a leaky joint can be the cause of reduced
power output and increased fuel consumption.

CYLINDER
Decarbon exhaust port and upper part of the cylinder,
taking care not to damage the cylinder wall surface.
The wear of the cylinder wall is determined from diameter reading taken at 20 mm from the top of the cylinder
with a cylinder gauge. If the wear thus determined
exceeds the limit indicated below, rework the bore to the
next oversize by using a boring machine or replace the
cylinder with a new one.
Cylinder gauge set : 09900-20508
Cylinder bore

Service limit 41.070 mm

After reworking the bore to an oversize, be sure to

chamfer the edges of ports and smooth the chamfered
edges with emery paper. To chamfer, use a scraper,
taking care not to nick the wall surface.

PISTON
CYLINDER TO PISTON CLEARANCE
Cylinder-to-piston clearance is the difference between
piston diameter and cylinder bore diameter. Be sure to
take the maked diameter at right angles to the piston
pin. The value of elevation is prescribed to be 15 mm
from the skirt end.
Micrometer(25~50 mm) : 09900-20202
Piston diameter

Service limit 40.885 mm

ENGINE 3-20

As a result of the above measurement, if the piston-tocylinder clearance exceeds the following limit, overhaul
the cylinder and use an oversize piston, or replace both
cylinder and piston. The measurement for the bore
diameter should be taken in the intake-to-exhaust port
direction and at 20mm from the cylinder top surface.
Standard

Serivice limit

Cylinder bore

41.005~41.020 mm 41.070 mm

Piston diameter

40.935~40.950 mm 40.885 mm

Cylinder to piston clearance 0.065~0.075 mm

0.120 mm

DE-CARBONING
De-carbon the piston and piston ring grooves, as illustrated. After cleaning the grooves, fit the rings and rotate
them in their respective grooves to be sure that they
move smoothly.
Carbon in groove is liable to cause the piston ring to get
stuck in the groove, and this condition will lead to
reduced engine power output.
A piston whose sliding surface is badly grooved or
scuffed due to overheating must be replaced. Shallow
grooves or minor scuff can be removed by grinding with
emery paper of about # 400.

PISTON PIN BORE I.D.

Using a caliper gauge, measure the piston pin bore
inside diameter. If reading exceeds the following service
limit, replace it with a new one.
Dial calipers : 09900-20605
Piston pin bore I.D.

Service limit 10.030 mm

3-21 ENGINE

PISTON PIN O.D.

Using a micrometer, measure the piston outside diameter at three positions.
Micrometer(0~25 mm) : 09900-20201
Piston pin O.D.

Service limit 9.980 mm

PISTON RINGS
Check each ring for end gap, reading the gap with a
thickness gauge shown in the illustration. If the end gap
is found to exceed the limit, indicated below, replace it
with a new one.
The end gap of each ring is to be measured with the
ring fitted squarely into the cylinder bore and held at the
least worn part near the cylinder bottom, as shown in
the illustration.
Thickness gauge : 09900-20806
Piston ring clearance
(Assembly condition)

Service Limit
0.75 mm

As the piston ring wears, its end gap increases reducing

engine power output because of the resultant blow by
through the enlarged gap. Here lies the importance of
using piston rings with end gaps within the limit.
Measure the piston ring free end gap to check the
spring tension.
Piston ring clearance(Free condition)

Service limit

1st

3.2 mm

2nd

3.1 mm

Fix the piston ring in the piston ring groove, measure the
ring side clearance with the thickness gauge while
matching the sliding surfaces of piston and ring.
Piston ring-ring groove clearance

Standard

1st

0.02~0.06 mm

2nd

0.02~0.06 mm

ENGINE 3-22

REED VALVE
When reinstalling the reed valve and stopper plate to
the body, align the both cut on the reed valve and stopper plate.
Apply THREAD LOCK 1324 to the stopper plate
securing screws.
Thread Lock1324

ENGINE REASSEMBLY
Reassembly is generally performed in the reverse order
of disassembly, but there are a number of reassembling
steps that demand or deserve detailed explanation or
emphasis. These steps will be taken up for respective
parts and components.
ell
S h
A valnia
3

OIL SEALS
Fit the oil seals to the crankcase following the procedure
below.
Replace removed oil seals with new ones.
Coat SUPER GREASEAto the lip of the oil seals.
Super GreaseA
Be sure to apply THREAD LOCK1324to outer
surfaces of right and left crankshaft oil seals to prevent them from moving.
Thread Lock1324

When fitting the oil seal in the crankcase, insert it

slowly with the special tools.
Oil seal installer : 09913-75830
Bearing installer attachment : 09924-74510
Bearing installer pilot : 09924-74540
NOTE:
Align the oil seal with edge of the crankcase as
shown in the illustration.

I ndustrial e
purpos
M ulti-

ase
G re

3-23 ENGINE

BEARINGS
Install new bearings with the special tool.
Bearing installer : 09913-75810
Bearing installer : 09913-76010

BUSHINGS

Using two steel tubes of appropriate size and a vise,

press the mounting bushings and into the
crankcase holes as shown in the illustration.

NOTE:
Knurled end should face inside. Protrusion and
should be in the same dimension.

ENGINE 3-24

Bushing
Bushing
Crankcase
Crankcase

CRANKSHAFT
Crank shaft
Crankcase RH
Oil seal
Oil seal
Oil pump drive gear
Oil pump driven gear
Oil seal

Measure the length between the webs referring to the

figure at right when rebuilding the crankshaft.
Width between webs

Standard 35.00.1 mm

3-25 ENGINE

When mounting the crankshaft into the crankcase, it

is necessary to pull its left end into the crankcase
with the special tool.
Crankshaft installer : 09910-32812
Conrod holder : 09910-20116
CAUTION

Never fit the crankshaft into the crankcase by

driving it with a plastic hammer. Always use the
special tool, otherwise crankshaft alignment
accuracy will be affected.

CRANKCASE
Wipe the crankcase mating surfaces(both
surfaces)with cleaning solvent.
Apply BOND1215uniformly to the mating surface
of the left half of the crankcase, and install the dowel
pins.
BOND1215
Install the two dowel pins.
Tighten the crankcase screws securely.
Check if the crankshaft rotates smoothly.

Install the new oil seal to the crankcase with the

special tool.

NOTE:
Align the oil seal with edge of the crankcase as
shown in the illustration.
Bearing installer : 09913-85210

ENGINE 3-26

CENTER STAND
Install the center stand .
Install the shaft , washer and cotter pin .

Hook the center stand spring into the crankcase.

3-27 ENGINE

REAR AXLE SHAFT, BRAKE AND WHEEL

Install the rear axle shaft into the crankcase by

tapping its end lightly.
Apply engine oil on the left end of the rear axle shaft
being inserted later in the reduction rear box cover.

Apply SUPER GREASEAlightly on the rear brake

cam pivot part and install it to the crankcase.
Super GreaseA
Turn to position the cam where the punched mark
on the end face is directed toward the axis of the rear
axle shaft.

Brake
cam

ENGINE 3-28

When installing the cam lever to the cam, align the

punched mark with the slit of cam lever.
Punch mark

Slit

Tighten the cam lever nut to the specified torque.

Rear brake cam lever nut : 6~9 Nm (0.6~0.9 kgm)

Install the brake shoes.

Apply SUPER GREASEAto the brake cam and
pin before installing the brake shoes.
Super GreaseA
CAUTION

Be careful not to apply too much grease to the

brake cam and pin. If grease gets on the lining,
brake effectiveness will be lost.

Install the rear wheel and nut.

Rear axle nut : 60~90 Nm (6.0~9.0 kgm)

3-29 ENGINE

TRANSMISSION

Install the circlip on to the rear axle shaft .

Assemble the idle shaft subassembly using the idle
shaft and thrust washer , then install the subassembly on the gear box.

Install the final driven gear on the rear axle shaft

using the circlip .

Thrust

Center
Circlip

Rounded coner

ENGINE 3-30

Install the new bearing , to the gear box cover

with the special tool.
Bearing installer : 09913-76010

Apply SUPER GREASEAto the lip of the oil seal

and install it to the gear box cover with the special
tool.
Super GreaseA

Oil seal

Bearing installer : 09913-70122

Align face

Install the washer, new gasket and dowel pin .

Install the driveshaft to the gear box cover.

3-31 ENGINE

Apply BOND1215at the hatched area shown in

the illustration and install the gear box cover on
the crankcase.
BOND1215
Tighten all the screws evenly one by one in a diagonal fashion.

STARTER DRIVEN GEAR AND STARTING MOTOR

Install the starter driven gear over the left

crankshaft end.
NOTE:
The convex side of hub should face outside when
installed in proper position.

ENGINE 3-32

Install the starting motor .

MOVABLE DRIVEN AND CLUTCH

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;;;;

3-33 ENGINE

Install the bearing in the fixed driven face with

the special tool.
Bearing installer : 09943-88211
CAUTION

Take care that hit inner race of the bearing.

(Fall to ring in the bearing a case.)

Install the circlip .

CAUTION

Instert surely in the circlip groove.

Thrust

Rounded coner

Install the bearing with the special tool.

Bearing installer : 09943-88211
CAUTION

A mark part of the bearing is pointed to the outside.

Install the new oil seals (, ) to the movable driven

face with the special tool.

Oil seal

Bearing installer : 09913-76010

Apply SUPER GREASEAto the lip of oil seals
and groove of movable driven faces inside.

Super GreaseA
Insert up to contact
to the stopper.

ENGINE 3-34

Install the movable driven face to the fixed driven

face .
CAUTION
Insert as guide the rim.

When reinstalling the movable dirven face to the

fixed dirven face, make sure that the oil seal is
positioned properly.

Position the two O-ring .

Install the pin at three places on the driven face
hub.
Apply SUPER GREASEAlightly to the cam part
where the pins are placed.
Super GreaseA

Pin

Spacer

Install the movable driven face seat .

CAUTION

The seat is installed rotatable naturally.

The O-ring get damaged, in case of installed by
force.

Install the spring .

Install the clutch shoe assembly and nut .

3-35 ENGINE

Tighten the clutch shoe nut to the specified torque

with the special tool.
Rotor holder : 09930-40113
Clutch shoe nut : 40~60 Nm (4.0~6.0 kgm)

Insert the V-belt between the driven faces as deep

inside as possible while pulling the movable driven
face all the way outside to provide the maximum belt
clearance.
CAUTION

The V-belt should be positioned so that the

arrows on the belt periphery point the normal
turning direction.
The V-belt contact face on the driven faces
should be thoroughly cleaned to be free from oil.

Thoroughly clean the clutch housing to be free

from oil and position it over the clutch shoe assembly.
Tighten the clutch housing nut to the specified
torque with the special tool.

Rotor holder : 09930-40113

Clutch housing nut : 40~60 Nm (4.0~6.0 kgm)

ENGINE 3-36

MOVABLE DRIVE

Install the roller to the movable drive face .

Mount the three dampers on the movable drive

plate and install it on the movable drive face .
Position the O-ring on the movable drive face.

3-37 ENGINE

Install the movable drive face cover .

CAUTION

Make sure that the movable drive plate is fully

positioned inside, or the weight roller may come
off.

Insert the spacer .

Position the movable drive face subassembly on the

crankshaft as shown in the photo.
CAUTION

Thoroughly clean the V-belt contact to be from oil.

Install the fixed drive face .

Tighten the kick starter driven nut to the specified
torque with the special tool.
Conrod holder : 09910-20115
Kick starter driven nut : 40~60 Nm (4.0~6.0 kgm)

Fill SUPER GREASEAin the groove provided

inside sliding surface of the kick driven gear and
install it on the end of the crankshaft. Wipe off
excess grease.

Super GreaseA
Install the spring and spacer .

ENGINE 3-38

Install the E-ring .

Continue turning the fixed drive face by hand until

the belt is seated in and both the drive and driven
faces will move together smoothly without slip.
Fill the final gear box with engine oil up to the level
hole.
Transmission oil capacity

Replace

110

Overhaul

130

Tighten the oil level bolt to the specified torque.

Oil level bolt : 9~15 Nm (0.9~1.5 kgm)

KICK STARTER

3-39 ENGINE

Apply SUPER GREASE A lightly on the kick

starter shaft rolling surface and install it on the
crankcase cover.

Super GreaseA
Position the kick starter shaft return spring and hook
the spring end on the crankcase cover boss .

Install the clutch cover and kick starter lever .

CAUTION

Install the kick starter lever as shown in the illustration.

Concur with the mark.

13

Tighten the kick starter lever bolt to the specified

torque.
Kick starter lever bolt : 8~12 Nm (0.8~1.2 kgm)

ENGINE 3-40

PISTON

Install the piston rings on the piston.

1st - Keystone ring
2nd - Barrel face ring
Expander ring

Position the ring so that the marking is on upside.

CAUTION

Position the ring so that the marking is on upside.

Locating pin

It is extremely important that, when the piston is fed

into the cylinder, each ring in place should be so
positioned as to hug the locating pin as shown in the
illustration.

CORRECT

INCORRECT

3-41 ENGINE

Apply engine oil on the piston pin and install the piston to the conrod.
CAUTION

The arrow mark on the piston head should

point the exhaust side.

The circlip should be mounted in such a position that

the mating ends of the circlip do not coincide with the
groove portion of the piston.
Position the cylinder base gasket.
Apply engine oil on the piston and cylinder wall surfaces and install the cylinder over the piston carefully.
Install the cylinder head gasket and cylinder head.

Tighten the cylinder head nut to the specification, and

tighten it diagonally several times as shown in the
illustration.
Cylinder head nut : 8~12 Nm (0.8~1.2 kgm)

Inside Outside

ENGINE 3-42

OIL PUMP AND INTAKE PIPE

Apply SUPER GREASEAto the oil pump driven

gear and install it to the crankcase.
Super GreaseA

Install the oil pump and tighten it to the specified

torque.
Oil pump bolt : 3~5 Nm (0.3~0.5 kgm)

3-43 ENGINE

Install the reed valve gasket , intake pipe gasket

and intake pipe with reed valve to the
crankcase.

MAGNETO

Degrease the tapered portion of the crankshaft and

also the magneto rotor.
Install the stator .
Install the key .

ENGINE 3-44

Install the rotor .

Apply THREAD LOCK1324to the rotor nut and
tighten it to the specified torque with the special tool.

Thread Lock1324
Rotor holder : 09930-40113

Magneto rotor nut : 35~45 Nm (3.5~4.5 kgm)

Install the fan case .

Install the magneto lead wire and starting motor lead
wire.

Install the cooling fan .

Install the cooling fan cover .

3-45 ENGINE

MUFFLER
Tighten the exhaust pipe bolts and muffler mounting
bolts to the specified torque.
Exhaust pipe bolt : 8~12 Nm (0.8~1.2 kgm)
Muffler mounting bolt : 18~28 Nm (1.8~2.8 kgm)

FUEL SYSTEM

CONTENTS
CARBURETOR

4- 1

REMOVAL

4- 1

DISASSEMBLY

4- 2

INSPECTION

4- 4

REASSEMBLY AND REMOUNTING

4- 5

FUEL TANK

4- 7

REMOVAL

4- 7

CLEANING

4- 8

REMOUNTING

4- 8

OIL PUMP

4- 8

FUEL PUMP

4- 9

4-1 FUEL SYSTEM

CARBURETOR

REMOVAL
Open the seat, and separate the helmet box by
removing the four lock nuts.

Remove the rear shock absorber mounting lower bolt.

FUEL SYSTEM 4-2

Remove the carburetor top cap , and disconnect

the throttle cable .

Disconnect the air vent hose , oil hose , and fuel

hose .

Remove the carburetor by loosening the mounting

bolts and clamp screw .

DISASSEMBLY
Remove the thermoelement assembly.

4-3 FUEL SYSTEM

CAUTION

Do not attempt to disassemble the thermoelement

assembly.
It is not serviceable.

Remove the float chamber .

Remove the float by removing the screw and

pin .

Remove the needle valve .

FUEL SYSTEM 4-4

Remove the throttle stop screw and pilot air screw .

CAUTION

When removing the pilot air

screw, record the revolutions until tighten completly.

Remove the main jet and needle jet .

INSPECTION
Check following items for any damage or clogging.
Pilot jet
Main jet
Pilot air screw
Needle jet air bleeding hole
Float
Gasket
Pilot outlet and bypass holes

NEEDLE VALVE INSPECTION

If foreign matter is caught between the valve seat and
the needle, the gasoline will continue flowing and cause
it to overflow. If the seat and needle are worn beyond the
permissible limits, similar trouble will occur. Conversely,
if the needle sticks, the gasoline will not float chamber.
Clean the float chamber and float parts with gasoline. If
the needle is worn as shown in the illustration, replace it
together with a valve seat. Clean the fuel passage of the
mixing chamber with compressed air.

Inspect the valve surface for worn

Foreign matter

4-5 FUEL SYSTEM

REASSEMBLY AND REMOUNTING

Reassemble following items.
Pilot air screw
Throttle stop screw
Main jet
Needle jet

Install the needle valve and float on the carburetor body.

Install the float pin and tightened the screw .

Install the gasket and float chamber.

Install the thermoelement assembly.

FUEL SYSTEM 4-6

Install the carburetor assembly.

Install the air vent hose , oil hose and fuel hose .

Install the carburetor top cap.

4-7 FUEL SYSTEM

FUEL TANK
REMOVAL

Remove the low leg shield .

Disconnect the fuel hose .

Disconnect the fuel level gauge lead wire .

Remove the six fuel tank mounting bolt.

FUEL SYSTEM 4-8

CLEANING
Dust from the fuel tank tends to bulid up in the fuel filter
which, when the fuel filter has been neglected for a long
period, inhibits the flow of fuel.
Remove the dust from, the fuel filter using compressed air.

REMOUNTING
Remount the fuel tank in the reverse of removal.

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;;
;
yyy
;;;
;
y
;;;
yyy
;;; yyy
yyy
;;;
;;;
yyy
;;;;
yyyy
;;
yy
;;;;
yyyy
;;
yy
;;;;
yyyy
;;;;
yyyy
;;;;
yyyy
;;;;
yyyy

OIL PUMP
AIR BLEEDING
Whenever evidence is noted of some air having leaked
into the oil pipe from the oil tank in a machine brought in
for servicing, or if the oil pump has to be removed for
servicing, be sure to carry out an air bleeding operating
with the oil pump in place before returning the machine
to the user.
To bleed air, hold the machine in standstill condition.
Loosen the air bleeding screw to let out air and after
making sure that the trapped air has all been bled, tighten the air bleeding screw completely.

4-9 FUEL SYSTEM

CHECKING OIL PUMP

Use the special tool, to check the pump for capacity by
measuring the amount of oil the pump draws during the
specified interval.
Remove the left side cover.
Have the CCI Oil gauge filled with HYOSUNG HYPOL
OIL and connect it to the suction side of the pump.
Run the engine at 3,000 rpm.
Holding engine speed at the same 3,000 rpm, let the
pump draw for 5 minutes. For this operation, the
reading taken on the device should be 6 ..
CCI Oil gauge : 09900-21602
Engine oil
discharge amount

1.0 ~ 1.2
(at 3,000 rpm for 5 minutes)

CAUTION

During this inspection, strictly follow the following points.

The machine should be rested on the center
stand.
Do not touch the rear wheel while running the
engine.

FUEL PUMP
REPLACE
Remove the rear shock absorber, and support the
center stand by a 70 mm wooden block.
Open the seat, and remove the trunk by loosing the
four nuts.
Remove the one lock nut of fuel pump.
Disconnect the inlet hose.
CAUTION

Stop up an entrance of the hose, to prevent that

the fuel leak out.
Disconnect the vacuum hose and outlet hose.
Remount in the reverse of removal after replacing the
fuel pump.

ELECTRICAL SYSTEM

CONTENTS
ELECTRICAL PARTS

5- 1

IGNITION/CHARGING SYSTEM

5- 2

IGNITION COIL

5- 2

STATOR COILS

5- 3

REGULATOR/RECTIFIER

5- 4

STARTER SYSTEM

5- 4

STARTING MOTOR INSPECTION

5- 5

STARTER RELAY INSPECTION

5- 6

FUEL LEVEL GAUGE

5- 7

OIL LEVEL CHECK LIGHT

5- 8

THERMOELEMENT

5- 9

SWITCHES INSPECTION

5-10

BATTERY

5-11

5-1 ELECTRICAL SYSTEM

ELECTRICAL PARTS
Ignition coil
Thermolement assembly
Fuel level gauge
Oil level gauge

Front turn signal

RH/LH
Head Lamp

Regulator

Turn signal cable

Rear brake
cable

Wiring
harness
Speedometer
cable
Brake
hose

ELECTRICAL SYSTEM 5-2

IGNITION/CHARGING SYSTEM

Stator

lgnition
coil

Regulator/Rectifier

CDI
unit

Spark
plug

Lighting
switch

H/L

T/L

Battery
12V 3AH
(MF)

M/L

Engine stop
switch
12V
15W2

12V
12V
5W 1.7W2

IGNITION COIL
Check the ignition coil with electro tester.
Test the ignition coil for sparking performance. Test
connection is as indicated. Make sure that the threeneedle sparking distance is at least 8mm. Test it at
least for 5 minutes.
Electro tester : 09900-28106
Spark performance

Over 8 mm

Yellow

Red(+)

Spark
Black
Black(-)

5-3 ELECTRICAL SYSTEM

Check the ignition coil with the pocket tester.

Pocket tester : 09900-25002
Ignition coil resistance
Primary

0.19 ~ 0.24

Secondary

5.4 ~ 6.6

B/R

C.D.I. UNIT
Using the pocket tester (R 1 range), measure the
resistance between the lead wire in the following table.
Pocket tester : 09900-25002
Unit :

Ground
Plug cap

Probe of tester to :

Probe of tester to :

B/Y
B/Y

W/BL

B/R

B/W

Br

7~10

3~4

7~10

5~7

W/BL 14~18

B/R

3~5

B/W 7~11

3~4.5

W 12~16

6~8

25~35

Br 10~14

5~7

1.2~2.5

B/R

B/W

Br

27~37
5~8

Using the pocket tester, measure the resistance

between the lead wire and ground. If the resistance
checked is incorrect, replace the coil.
Unit :
Stator coil resistance
Standard resistance

(Red)

(Black)

Y/W

Ground

Lighting coil 0.54 ~ 0.80

W/R

Ground

Charging coil 0.69 ~ 1.03

B/R

Ground

Exciting coil

220 ~ 260

Br

Pick-up coil

90 ~ 110

CHARGING OUTPUT CHECK

Start the engine and keep it running at 5,000 rpm with lighting
switch turnedON
.
Measure the DC voltage between the battery terminal and
with a pocket tester.
If the tester reads under or over following specification, check
the no-lead performance or replace the regulator/rectifier.
CAUTION

When making this test, be sure that the battery is

in fully-charged condition.
Pocket tester : 09900-25002
Engine tachometer : 09900-26006
Standard charging output

W/BL

3~4.5 1.2~2.5

STATOR COILS

Lead wire of tester

B/Y

13.0 ~ 16.0 V (at 5,000 rpm)

ELECTRICAL SYSTEM 5-4

NO-LOAD PERFORMANCE OF A.C. GENERATOR

Disconnect the magneto lead wire coupler.
Start the engine and keep it running at 5,000 rpm.
Using a pocket tester, measure the AC voltage
between the three lead wire. If the tester reading is as
follows, magneto is in good condition.
Standard no-load performance
More than 17 V (at 5,000 rpm)
of A.C. generator

REGULATOR/RECTIFIER
Disconnect the coupler.
Using the pocket tester(1 Range), measure the
resistance between the terminals as shown in the following table. If the resistance checked is incorrect,
replace the regulator/rectifier.
Pocket tester : 09900-25002

Unit :

Probe of tester to:

Probe of tester to:

502~ 260

50 ~ 230

10 ~ 100

STARTER SYSTEM
The starter system is shown in the diagram below: namely, the starting motor, starter relay, starter switch and battery.
Depressing the starter switch (on the right handlebar switch box) while squeezing the front or rear brake lever energizes
the relay, causing the contact points to close which connects the starting motor to the battery.
Starter relay
R

R/W

Fuse
Y/G
IG switch

Starter switch
Point

Brake switch
Battery

W/B

Starter
motor

5-5 ELECTRICAL SYSTEM

STARTING MOTOR REMOVAL AND DISASSEMBLY

Remove the starting motor.
Disassemble the starting motor as shown in the illustration.

STARTING MOTOR INSPECTION

CARBON BRUSHES
When the brushes are worn, the motor will be unable to
procedure sufficient torque, and the engine will be difficult to turn over. To prevent this, periodically inspect the
length of the brushes and replace them when they are
too short or chipping.
Carbon brushes wear

Service limit 4 mm

COMMUTATOR
If the commutator surface is dirty, starting performance
will decrease. Polish the commutator with #400 or similar fine emery paper when it is dirty. After polishing wipe
the commutator with a clean dry cloth.
Measure the commutator under cut .
Commutator under cut

Service limit 4 mm

Segment

ELECTRICAL SYSTEM 5-6

ARMATURE COIL
Using the pocket tester, check the coil for open and
ground by placing probe pins on each commutator segment and rotor core (to test for ground)and on any two
segments at various places (to test for open), with the
brushes lifted off the commutator surface.
If the coil is found to be open-circuited or grounded,
replace the armature. Continuous use of a defective
armature will cause the starting motor to suddenly fail.
Pocket tester : 09900-25002

STARTER RELAY INSPECTION

Disconnect the starter relay lead wire coupler.
Check the coil foropen,groundand ohmic resistance. The coil is in good condition, if the resistance
is as follows.
Pocket tester : 09900-25002
Starter relay standard resistance

0 ~ 70

5-7 ELECTRICAL SYSTEM

FUEL LEVEL GAUGE

Fuel level gauge

B/W

Y/B

Fuel tank

FUEL LEVEL METER/GAUGE

FUEL METER INSPECTION
To test the Fuel Meter two different checks may be
used.
The first, and simplest test will tell if the meter is operating but will not indicate the meters accuracy throughout
the range. To perform this test, lift the seat and remove
the right frame cover, then disconnect the B/W and Y/B
lead connector of the fuel gauge sending unit. Connect
a jumper wire between B/W and Y/B wires coming from
the main wiring harness. With the ignition switch turned
ON, the fuel meter should indicateF.
The second test will check the accuracy of the meter in
the full and empty positions. Connect a 90 resistor
between the Y/B and B/W lead wires. The fuel meter is
normal if its pointer indicates the E(empty) position
when the specified voltage is applied to the circuit and if
its pointer indicates the F(full) position when the resistor
is changed to 10 .

ELECTRICAL SYSTEM 5-8

If either one or both indications are abnormal, replace

the fuel meter with a new one.

FUEL GUAGE SENDING UNIT INSPECTION

Disconnect the lead wires coming out of the fuel
gauge and check resistance of each position.
If the resistance measured is incorrect, replace the
fuel gauge assembly with a new one.
The relation between the position of the fuel gauge
float and resistance is shown in the following table.

Relation between the position of the fuel

gauge float and resistance
Float position

Resistance

F(Full)

10

1/2

38

E(Empty)

90

0
-6

1/2

+ 10
0

OIL LEVEL CHECK LIGHT

Oil level switch

Oil level check light

IG switch

Battery

5-9 ELECTRICAL SYSTEM

OIL LEVEL SWITCH INSPECTION

Check the oil level switch for continuity between the lead
wire. If the tester does not show the value of 0 ~ 1
when the switch ring is in bottom position, file the contact
surface or replace the unit.

Switch

Pocket tester : 09900-25002

OIL LEVEL CHECK LIGHT INSPECTION

Disconnect the L/W and B/W lead connector of the oil
level check light.
Connect a jumper wire between L/W and B/W wires
coming from the main wiring harness. With the ignition
switch turned ON, the oil level check light should flash.
If there is no flash, check the wiring harness continuity
and the bulb blown out.

THERMOELEMENT

B/R

R
Y/W R/W

Battary

Regurator/Rectifier
PTC

Magneto

ELECTRICAL SYSTEM 5-10

INSPECTION
Disconnect the thermoelement coupler .
Connect the thermoelement coupler to a 12V battery and touch the thermoelement to check the
temperature being raised.
The thermoelement should become heated to a
temperature more than that of human body within
five minutes. If not, replace with new one.

CAUTION

This check should be carried out when the carburetor is cold.

SWITCHES INSPECTION
STARTER SWITCH
Inspect each switch for continuity with the pocket tester
referring to the chart. If it is found any abnormality,
replace the respective switch assembly with new one.

ON

W/B

Y/G

OFF

Pocket tester : 09900-25002

FRONT AND REAR LAMP SWITCH

ON
WIRE COLOR
B
L
G
Gr
Sb
Lg
O
R
W
Y
B/R
B/W
W/B
Y/W
Y/G
L/W

W/B

OFF
Black
Blue
Green
Gray
Light blue
Light green
Orange
Red
White
Yellow
Black with Red tracer
Black with White tracer
White with Black tracer
Yellow with White tracer
Yellow with Green tracer
Blue with White tracer

TURN SIGNAL LAMP SWITCH

Lg
L

Sb

HORN SWITCH
ON

B/W

OFF

IGNITION SWITCH
B/W

B/R

LOCK

OFF

LIGHTING SWITCH
ON
OFF

Gr

Y/W

ON
C

L/W

5-11 ELECTRICAL SYSTEM

BATTERY
BATTERY
Type

YT4L-BS

Capacity

12V, 3AH/10HR

Standard electrolyte S.G.

1.32(at 20)

Filter
Cap

Safety valve

CAUTION OF BATERY ELECTROLYTE

TREATMENT
Pay attention that the battery electrolyte not be stain
the chasis or the humanbody.
If be stain the chasis or the humanbody, at once
wash a vast quantity of water.
When it be stained, clothes should come into being a
hole or painting should take off.
Be cured from a doctor.
When the battery electrolyte was droped the surface
of land, wash a vast quantity of water.
Neutralize by hydroxide, bicarbonate of soda and so
on.

INITIAL CHARGING
FILLING ELECTROLYTE
Remove the aluminum tape sealing the battery
electrolyte filler holes .

Remove the caps .

CAUTION

After filling the electrolyte completely, use the

removed cap as the sealed caps of battery-filler
holes.
Do not remove or pierce the sealed areas of
the electrolyte container.

Pole plate
Pole plate
Separator
(fiberglass plate)

ELECTRICAL SYSTEM 5-12

Insert the nozzles of the electrolyte container into the

battery
s electrolyte filler holes, holding the container
firmly so that it does not fall.
CAUTION

Take precaution not to allow any of the fluid to

spill.
The electrolyte container insert at right angles
so that it is not sloped.

Make sure air bubbles are coming up each electrolyte container, and leave in this position for about
more than 20 minutes.

NOTE:
If no air bubbles are coming up from a filler port, tap the
bottom of the two or three times.
Never remove the container from the battery.

After confirming that the electrolyte has entered the

battery completely, remove the electrolyte containers
from the battery. Wait for around 20 minutes.
Insert the caps into the filler holes, pressing in
firmly so that the top of the caps do not protrude
above the upper surface of the batterys top cover.
CAUTION

Clean completely in case that the electrolyte is

adhered at the filler hole.
Once install the caps to the battery, do not
remove the caps.

5-13 ELECTRICAL SYSTEM

Using the pocket tester, measure the battery voltage.

The tester should indicate more than 12.5-12.6
V(DC)as shown in the Fig. If the battery voltage is
lower than the specification, charge the battery with a
battery charger.

(at 25)
seconds

NOTE:
Initial charging for a new battery is recommended if two
years have elapsed since the date of manufacture.
(Minutes)
Time

CAUTION OF BATTERY TREATMENT

The battery is needed attention generally as occur flammability gas.
If does not, it should be explosion and severe accident.
Pay attention to the following points.
Prohibit positively that come in contact with short, spark or firearms.
The battery recharge where be well-ventilated wide place.
Prohibit positively at the shut tight room.

RECHARGING OPERATION

BATTERY CHARGING CURRENT

Standard

0.4A 5~10 Hours

Fast

4A 30 Minutes

Voltage

Using the pocket tester, check the battery voltage. If

the voltage reading is less than 12.0V(DC), recharge
the battery with a battery charger.
When recharging the battery, remove the battery
from the motorcycle.
Do the battery by standard charging usually.

After recharging, wait for more than 30 minutes and

check the battery voltage with a pocket tester.
If the battery voltage is less than 12.0V, recharge the
battery again.
If the battery voltage is still less than 12.0V after
recharging, replace the battery with a new one.

(at 0~40)

Voltage

NOTE:
When a battery is left for a long term without using, it is
subject to discharge. When the motorcycle is not used
for more than 1 month(especially during the winter season), recharge the battery once a month at least.

(Minutes)
Time

WARNING

Charging equipment of this motorcycle is

designed for the MF(Maintenance Free) battery.
No use except the specificated battery.

Battery charged condition

CHASSIS

CONTENTS
FRONT WHEEL

6- 1

FRONT BRAKE

6- 7

FRONT FORK

6-14

STEERING

6-18

REAR WHEEL AND REAR BRAKE

6-22

6-1 CHASSIS

FRONT WHEEL

REMOVAL AND DISASSEMBLY

Remove the front brake caliper by removing the
mounting bolts .
CAUTION

Do not operate the front brake lever while dismounting the caliper.

CHASSIS 6-2

Remove the front axle nut.

Support the motocycle by jack or wooden block.
Remove the front wheel and speedometer gear box
by removing the front axle shaft.

Remove the disc plate by removing the bolts.

Remove the spacer .

Remove the oil seal with the special tool.

Oil seal remover : 09913-50121

6-3 CHASSIS

Drive out the both bearing with the special tool in the following procedures.
Insert the adapter into the bearing.
After inserting the wedge bar from the opposit side,
lock the wedge bar in the slit of the adapter.
Drive out the bearing by knocking the wedge bar.
Wheel bearing remover : 09941-50111

CAUTION

The removed dust seal and bearing should be

replaced with new ones.

INSPECTION
WHEEL RIM
Make sure that the wheel rim runout does not exceed
the service limit when checked as shown.
An excessive runout is usually due to worn or loose
wheel bearings and can be reduced by replacing the
bearings. If bearing replacement fails to reduce the
runout, replace the wheel.
Wheel rim runout
(Axle and Radial)

Service limit 3.0 mm

Dial gauge(1/100 mm) : 09900-20606

Magnetic stand : 09900-20701

TIRE
Inspect the tires for wear and damage, and check the
tire tread depth as shown. Replace a badly worn or damaged tire. A tire with its tread worn down to the limit(in
terms of tread depth)must be replaced.

CHASSIS 6-4

Tire depth
service limit

Front

1.6 mm

Rear

1.6 mm

Check the tire pressure, and examine the value for evidence of air leakage.
Normal riding
TIRE PRESSURE
Cold inflation

Solo riding

Dual riding

kg/

kPa

kg/

kPa

Front

1.25

123

1.75

172

Rear

2.00

196

2.25

221

REASSEMBLY AND REMOUNTING

Reassemble and remount the front wheel in the reverse
order diassembly and removal, and also carry out the
following steps.
WHEEL BEARING
Apply SUPER GREASEAto the bearings before
installing.

ell
S h
A valnia
3

Super GreaseA

Install the wheel bearings by using the special tool.

I ndustrial e
purpos
M ulti-

ase
G re

Bearing installer set : 09924-84521

CAUTION

First install the wheel bearing for left side.

Right side

Left side
Bearing(R)

Bearing(L)

Clearance

Spacer

Bearing(L)

6-5 CHASSIS

OIL SEAL
Install the oil seal with the special tool.
Oil seal installer : 09923-55131

Install the spacer .

DISC PLATE
Install the disc plate and tighten them to the specified
torque.
Front brake disc bolt : 18 ~ 28 Nm(1.8 ~ 2.8 kgm)

SPEEDOMETER GEAR BOX

When installing the speedometer gear box, align the
two drive pawls with the two recesses of the
wheel hub.

CHASSIS 6-6

CAUTION

After touching the speedometer gear box to

the stopper , tighten the axle shaft.

FRONT WHEEL
Tighten the front axle nut to the specified torque.
Front axle nut : 33 ~ 52 Nm(3.3 ~ 5.2 kgm)

Tighten the caliper mounting bolts to the specified

torque.
Front brake caliper mounting bolt
: 18 ~ 28 Nm(1.8 ~ 2.8 kgm)

6-7 CHASSIS

FRONT BRAKE

BRAKE PAD REPLACEMENT

Remove the caliper by removing the brake caliper
mounting bolts .
CAUTION

Do not operate the front brake lever while dismounting the caliper.

CHASSIS 6-8

Reassemble it after remove the brake pads .

CAUTION

Replace the brake pads as a set, otherwise braking performance will be adversely affected.

CALIPER REMOVAL AND DISASSEMBLY

Remove the brake hose and catch the brake fluid
in a suitable receptacle.
Remove the caliper mounting bolt .
CAUTION

Never re-use the brake fluid left over from the last
servicing and stored long periods.

Remove the caliper.

Remove the brake pads.
Remove the pad holder .

Remove the spring .

6-9 CHASSIS

Place a rag over the piston to prevent popping up.

Force out the piston with a air gun.
CAUTION

Do not use high pressure air to prevent piston

damage.

Remove the dust seal and piston seal .

CALIPER INSPECTION
Inspect the caliper cylinder bore wall for nicks, scratches
or other damage.
Inspect piston for damage and wear.

Inspect each rubber part for damage and wear.

CHASSIS 6-10

CALIPER REASSEMBLY

Reassemble and remount the caliper in the reverse

order of removal and disassembly, and also carry out the
following steps.
CAUTION

Wash the caliper components with fresh brake

fluid before reassembly. Never use cleaning solvent or gasoline to wash them. Apply brake fluid
to the caliper bore and piston to be inserted into
the bore.
Apply SILICONE GREASE to the caliper holder.
Silicone Grease

SPECIFIED TORQUE
Item

Nm

kgm

18 ~ 28

1.8 ~ 2.8

20 ~ 25

2.0 ~ 2.5

WARNING

Bleed the air from brake fluid circuit after

reassembling caliper.(Refer to page 2-9)

DISC PLATE REMOVAL AND DISASSEMBLY

Remove the front wheel.(Refer to page 6-2)
Remove the disc plate.(Refer to page 6-2)
Install the disc plate.(Refer to page 6-4)

DISC PLATE INSPECTION

Check the disc for wear with a micrometer. Its thickness can be checked with disc and wheel in place.
Replace the disc if the thickness exceeds the service
limit.
Disc thickness

Service limit 3.5 mm

Micrometer(0 ~ 25mm) : 09900-20201

6-11 CHASSIS

With the disc mounted on the wheel, check the disc

for face runout with a dial gauge as shown. Replace
the disc if the runout exceeds the service limit.
Dial gauge(1/100 mm) : 09900-20606
Magnetic stand : 09900-20701

Disc runout

Service limit 0.3 mm

MASTER CYLINDER REMOVAL AND

DISASSEMBLY
Remove the handlebar cover.
Disconnect the front brake lamp switch lead wires.

Place a cloth underneath the union bolt on the master

cylinder to catch spilled drops of brake fluid. Unscrew
the union bolt and disconnect the brake hose/master
cylinder joint.
CAUTION

Completely wipe off any brake fluid adhering to

any part of motorcycle. The fluid reacts chemically with paint, plastics, rubber materials, etc.

Remove the master cylinder.

CHASSIS 6-12

Remove the brake lever and brake switch .

Remove the dust boot .

Remove the circlip with the special tool.

Snapring pliers : 09900-06108

Remove the piston/primary cup with return spring .

Remove the reservoir cap and diaphragm .
Drain brake fluid.

6-13 CHASSIS

MASTER CYLINDER INSPECTION

Inspect the master cylinder bore for any scratches or
other damage.
Inspect the piston surface for scratches or other damage.
Inspect the primary cup and dust boot for wear or damage.

MASTER CYLINDER REASSEMBLY AND

REMOUNTING
Reassemble and remount the master cylinder in the
reverse order of removal and disassembly, and also
carry out the following steps.

Boot

CAUTION

Wash the master cylinder components with fresh

brake fluid before reassembly. Never use cleaning solvent or gasoline to wash them.
Apply brake fluid to the cylinder bore and all the
internals to be inserted into the bore.

Circlip
spring
Piston
Primary cap
Second cap

Reassemble and remount the master cylinder.(Refer

to page 6-11)
When remounting the master cylinder on the handlebar, first tighten the clamp bolt for upside.
CAUTION

Master cylinder

Upside

Bleed air after remounting the master cylinder.

Handlebar

Clearance

CHASSIS 6-14

FRONT FORK

REMOVAL AND DISASSEMBLY

Remove the front leg shield.
Remove the front brake caliper by removing the
mounting bolts.
CAUTION

Do not operate the front brake lever while dismounting the caliper.

6-15 CHASSIS

Remove the front axle nut.

Support the motorcycle by jack or wooden block.
Remove the front wheel by removing the front axle
shaft.

Loosen the front fork bolt, then draw out the fork
spring.
Loosen the front fork lower clamp bolts.

Invert the fork and stroke it several times to remove

the oil.
Hold the fork inverted for a few minutes.

Remove the socket bolt with the hexagon wrench.

Seperate the fork pipe and pipe seat .

CHASSIS 6-16

Remove the dust boot and stopper ring .

Remove the oil seal by using the special tool.

CAUTION

The oil seal removed should be replaced with a

new oil seal.
Oil seal remover : 09913-50121

INSPECTION
Inspect pipe seat for wear and damage.

Inspect fork pipe and bottom case sliding surfaces for

any scuffing or flaws.

6-17 CHASSIS

FORK SPRING
Measure the fork spring free length.
Fork spring free length

Standard 290.9 mm
290.9

REASSEMBLY AND REMOUNTING

Reassemble and remount the fork in the reverse order of
removal and disassembly, and also carry out the following steps.

FRONT FORK BOLT

Apply BOND1215and THREAD LOCK1324to
the fork bolt and tighten the bolt with specified torque.
Bond1215
Thread Lock1324
Front fork bolt : 35 ~ 55 Nm(3.5 ~ 5.5 kgm)

FORK OIL
For the fork oil, be sure to use a front fork oil whose
viscosity rating meets specification below.
Up side

Fork oil type

TELLUS # 37

Capacity

50 cc(One side)

CUSHION SPRING
When installing the front fork spring, the close end
should position upside.

CHASSIS 6-18

STEERING
REMOVAL AND DISASSEMBLY
Remove the handlebar cover.
Remove the handlebar by removing the clamp bolt
and set bolt .

Loosen the steering stem lock nut with the special

tool.
Clamp wrench : 09940-10122

Remove the front fork assembly by removing the lock

washer , steering outer upper race and dust seal
.

CAUTION

Do not drop the steering stem steel balls.

Remove the steering outer lower race with a chisel.

6-19 CHASSIS

Remove the steering stem steel balls .

Number of steel ball
Upper

22 pcs

Lower

25 pcs

Remove the upper and lower bearing inner race with

an appropriate bar.

INSPECTION
Inspect the removed parts for the following abnormalities.
Bearing race wear and brinelling.
Worn and damaged steel balls.
Distortion of steering stem or handlebar.

REASSEMBLY AND REMOUNTING

Reassemble and remount the steering stem, handlebar
and front fork in the reverse order of disassembly and
removal, and also carry out the following steps.
OUTER LOWER RACE
Press in the outer lower race .

CHASSIS 6-20

INNER RACE
Press in the upper and lower inner races with the special tool.
Steering race installer : 09941-34513

STEEL BALL
Apply SUPER GREASE A when installing the
upper and lower steel balls.
Super GreaseA

Number of steel ball

Upper

22 pcs

Lower

25 pcs

STEERING OUTER UPPER RACE NUT

Tighten the steering outer upper race until resistance is felt, then loosen it 1/8 ~ 1/4 turn.
CAUTION

Make sure that the steering turns smoothly and

easily, left to right.

Tighten the steering stem lock nut with the special

tool.
Clamp wrench : 09940-10122
Steering stem lock nut
: 60 ~ 100 Nm(6.0 ~ 10.0 kgm)

6-21 CHASSIS

Install the handlebar and tighten the set bolt and

clamp bolt to the specified torque.
Handlebar set bolt : 22 ~ 28 Nm(2.2 ~ 2.8 kgm)
Handlebar clamp bolt : 48 ~ 52 Nm(4.8 ~ 5.2 kgm)

After install the front fork and steering stem, inspect

the following items.
Lift the front fork.
Inspect play of the front fork as that grasp lower of
the front fork and shake it by the front and rear.
By the handle turning the right or left, inspect
whether turning smoothly.
Adjust the outer upper race, if the steering is comed
heavy and tight.
Bleed air of the front brake.(Refer to page 2-9)

CHASSIS 6-22

REAR WHEEL AND REAR BRAKE

REMOVAL AND DISASSEMBLY

Place the motorcycle on level ground.
Remove the muffler.(Refer to page 3-4)
Remove the rear wheel by removing the axle nut .

6-23 CHASSIS

INSPECTION
REAR BRAKE DRUM
Measure the brake drum I.D. to determine the extent of
wear and, if the limit is exceeded by the wear noted,
replace the drum. The value of this limit is indicated
inside the drum.
Rear brake drum I.D

Service limit 100.7 mm

BRAKE SHOE
Using a vernier calipers, measure the brake shoe outside diameter at the place as shown in the photo. If the
measurement is less than the limit, replace the brake
shoe.
Brake shoe lining for thickness

Service limit 96 mm

CAUTION

Replace the brake shoe with a set, otherwise

braking performance will be adversely affected.
WHEEL
Refer to page 6-3.
TIRE
Refer to page 6-4.

REASSEMBLY AND REMOUNTING

Reassemble and remount the rear wheel and brake in
the reverse order of removal, and diassembly.

Front
Punch mark

BRAKE CAM LEVER

When installing the brake cam lever, align the
punched mark of camshaft with the slit on cam lever.
Brake cam lever bolt : 6 ~ 9 Nm(0.6 ~ 0.9 kgm)

REAR BRAKE SHOE

Apply SUPER GREASEAto the camshaft and pin
before installing the brake shoes.
Super GreaseA

CAUTION

Be careful not to apply too much grease to the

camshaft and pin. If grease gets on the lining,
brake effectiveness will be lost.

Slit

Front

CHASSIS 6-24

REAR AXLE NUT

Tighten the rear axle nut to the specified torque.
Rear axle nut : 60 ~ 90 Nm(6.0 ~ 9.0 kgm)

SERVICING INFORMATION

CONTENTS
TROUBLESHOOTING

7- 1

SPECIAL TOOLS

7- 6

TIGHTENING TORQUE

7-10

SERVICE DATA

7-12

WIRE AND CABLE ROUTING

7-18

WIRING DIAGRAM

7-20

7-1 SERVICING INFORMATION

TROUBLESHOOTING
ENGINE
Complaint
Engine does not
start, or is hard
to start.

Symptom and possible causes

Remedy

Compression too low

1. Excessively worn cylinder or piston rings.
2. Stiff piston ring in place.
3. Gas leaks from the joint in crankcase, cylinder or cylinder head.
4. Damaged reed valve.
5. Spark plug too loose.
6. Broken, cracked or otherwise failed piston.

Replace.
Refair or replace.
Refair or replace.
Replace.
Tighten.
Replace.

Plug not sparking

1. Damaged spark plug or spark plug cap.
2. Dirty or wet spark plug.
3. Defective CDI & Ignition coil unit or stator coil.
4. Open or short in high-tension cord.
5. Defective ignition switch.

Replace.
Clean and dry.
Replace.
Replace.
Replace.

No fuel reaching the carburetor

1. Clogged hole in the fuel tank cap.
2. Clogged or defective fuel cock.
3. Defective carburetor float valve.
4. Clogged fuel hose or defective vacuum hose.

Clean.
Clean or replace.
Replace.
Clean or replace.

Engine stalls
easily.

1. Carbon deposited on the spark plug.

2. Defective CDI & Ignition coil unit.
3. Clogged fuel hose.
4. Clogged jets in carburetor.
5. Clogged exhaust pipe.

Clean.
Replace.
Clean.
Clean.
Clean.

Noisy engine.

Noise appears to come from piston

1. Piston or cylinder worn down.
2. Combustion chamber fouled with carbon.
3. Piston pin, bearing or piston pin bore worn.
4. Piston rings or ring grooves worn.

Replace.
Clean.
Replace.
Replace.

Noise seems to come from crankshaft

1. Worn or brunt crankshaft bearings.
2. Worn or brunt conrod big-end bearings.

Replace.
Replace.

Noise seems to come from final gear box

1. Gears worn or rubbing.
2. Badly worn splines.
3. Worn or damaged bearings of drive shaft for rear axle shaft.

Replace.
Replace.
Replace.

Slipping clutch

1. Worn or damaged clutch shoes.

2. Worn clutch drum.

Replace.
Replace.

Engine idles
poorly.

1. Excessively worn cylinder or piston rings.

2. Stiff piston ring in place.
3. Gas leaks from crankshaft oil seal.
4. Spark plug gaps too wide.
5. Defective CDI & Ignition coil unit.
6. Defective magneto stator coil.
7. Float-chamber fuel level out of adjustment in carburetor.
8. Clogged jets in carburetor.
9. Broken or damaged reed valve.

Replace.
Replace.
Replace.
Adjust or replace.
Replace.
Replace.
Replace.
Clean or adjust.
Replace.

SERVICING INFORMATION 7-2

Complaint
Engine runs
poorly in highspeed range.

Symptom and possible causes

Remedy

1. Excessively worn cylinder or piston rings.

2. Stiff piston ring in place.
3. Spark plug gaps to narrow.
4. Ignition not advanced sufficiently due to poorly working CDI
& Ignition coil unit.
5. Defective magneto stator coil.
6. Float-chamber fuel level too low.
7. Clogged air cleaner element.
8. Clogged fuel hose, resulting in inadequate fuel supply to carburetor.
9. Clogged fuel cock vacuum pipe.

Replace.
Replace.
Adjust.
Replace.

Dirty or heavy
exhaust smoke.

1. Too much engine oil to the engine.

2. Use of incorrect engine oil.

Check oil pump.

Change.

Engine lacks
power.

1. Excessively worn cylinder or piston rings.

2. Stiff piston ring in place.
3. Gas leaks from crankshaft oil seal.
4. Spark plug gaps incorrect.
5. Clogged jets in carburetor.
6. Float-chamber fuel level out of adjustment.
7. Clogged air cleaner element.
8. Fouled spark plug.
9. Sucking air from intake pipe.
10. Slipping or worn V-belt.
11. Damaged/worn rollers in the movable drive face.
12. Weakened movable driven face spring.
13. Too rich fuel/air mixture due to defective starter system.

Replace.
Replace.
Replace.
Adjust or replace.
Clean.
Adjust or replace.
Clean.
Clean or replace.
Retighten or replace.
Replace.
Replace.
Replace.
Replace.

Engine overheats.

1. Heavy carbon deposit on piston crown.

2. Defective oil pump or clogged oil circuit.
3. Fuel level too low in float chamber.
4. Air leakage from intake pipe.
5. Use of incorrect engine oil.
6. Use of improper spark plug.
7. Clogged exhaust pipe/muffler.

Clean.
Replace or clean.
Adjust or replace.
Retighten or replace.
Change.
Change.
Clean or replace.

Replace.
Adjust or replace.
Clean
Clean, and replace.
Clean.

CARBURETOR
Complaint
Trouble with
starting.

Symptom and possible causes

Remedy

3. Air leaking from carburetors joint or vacuum hose joint.

4. Starter plunger is not operating properly.

Clean.
Check starter body and carburetor
for tightness, and replace gasket.
Check and replace.
Check and replace.

Idling or low-speed
trouble.

1. Pilot jet, pilot air jet are clogged or loose.

2. Air leaking from carburetors joint, vacuum pipe joint, or starter.
3. Pilot outlet is clogged.
4. Starter plunger is not fully closed.

Check and clean.

Clean and replace.
Check and clean.
Check and replace.

Medium or highspeed trouble.

1. Main jet or main air jet is clogged.

2. Needle jet is clogged.
3. Fuel level is improperly set.
4. Throttle valve is not operating properly.
5. Fuel filter is clogged.

Check and clean.

Check and clean.
Check and replace.
Check throttle valve for operation.
Check and clean.

Overflow and fuel

level fluctuations.

1. Needle valve is worn or damaged.

2. Spring in deedle valve is broken.
3. Float is not working properly.
4. Foreign matter has adhered to needle valve.
5. Fuel level is too high or low.

Replace.
Replace.
Check and adjust.
Clean.
Adjust or replace.

1. Starter jet is clogged.

2. Air leaking from a joint between starter body and carburetor.

7-3 SERVICING INFORMATION

ELECTRICAL
Complaint

Symptom and possible causes

Remedy

No sparking or
poor sparking.

1. Defective CDI & Ignition coil unit.

2. Defective spark plug.
3. Defective magneto stator coil.
4. Loose connection of lead wire.

Replace.
Replace.
Replace.
Connect/tighten.

Spark plug soon

becomes fouled
with carbon.

1. Mixture too rich.

2. Idling speed set too high.
3. Incorrect gasoline.
4. Dirty element in air cleaner.
5. Spark plug too cold.
6. Incorrect engine oil.

Adjust carburetor.
Adjust carburetor.
Change.
Clean.
Replace by hot type plug.
Replace.

Spark plug
electrodes overheat
or burn.

1. Spark plug too hot.

2. The engine overheats.
3. Spark plug loose.
4. Mixture too lean.
5. Not enough engine oil.

Replace by hot type plug.

Turn up.
Retighten.
Adjust carburetor.
Check oil pump.

Magneto does not

charge.

1. Open or short in lead wires, or loose lead connections.

2. Shorted, grounded or open magneto coil.
3. Shorted or open regulator/rectifier.

Repair, replace or retighten.

Replace.
Replace.

Magneto charge,
but charging rate is
below the specifications.

1. Lead wires tend to get shorted or open-circuited or

loosely connected at terminal.
2. Grounded or open-circuited stator coils of magneto.
3. Defective regulator/rectifier.
4. Defective cell plates in the batttery.

Repair, or retighten.

Magneto
overcharges

1. Internal short-circuit in the battery.

2. Resistor element in the regulator/rectifier damaged or defective.
3. Regulator.rectifier unit poorly grounded.

Replace the battery.

Replace.
Clean and tighten groun connection.

Ustable charging.

1. Lead wire insulation frayed due to vibration,

resulting in intermittent shorting.
2. Magneto coil internally shorted.
3. Defective regulator/rectifier.

Repair or replace.

1. Battery run down.

2. Defective switch contacts.
3. Brushes not seating properly on commutator in starter motor.
4. Defective starter relay.
5. Defective starter pinion gears.
6. Defective front or rear brake light switch circuit.

Recharge or replace.
Replace.
Repair or replace.
Replace.
Replace.
Replace or repair.

Starter button is
not effective.

Replace.
Replace.
Replace the battery.

Replace.
Replace.

BATTERY
Complaint
Battery runs down
quickly.

Symptom and possible causes

1. The charging method is not correct.

2. Cell plates have lost much of their active material as a result

of over-charging.
3. A short-circuit condition exists within the battery due to
excessive accumulation of sediments caused by the incorrect
electrolyte.
4. Battery is too old.

Remedy
Check the magneto and regulator/rectifier circuit connections, and make
necessary adjustments to obtain specified charging operation.
Replace the battery, and correct
the charging system.
Replace the battery.
Replace the battery.

Reversed battery
polarity.

1. The battery has been connected the wrong way round in the
system, so that it is being charged in the reverse direction.

Replace the battery and be sure to

connect the battery properly.

Battery discharges
too rapidly.

1. Dirty container top and sides.

2. Battery is too old.

Clean.
Replace.

SERVICING INFORMATION 7-4

CHASSIS
Complaint

Symptom and possible causes

Remedy

Handling feels
too heavy.

1. Steering stem nut overtightened.

2. Broken bearing/race in steering stem.
3. Distorted steering stem.
4. Not enough pressure in tires.

Adjust.
Replace.
Replace.
Adjust.

Wobbly handle.

1. Loss of balance between right and left front suspension.

2. Distorted front axle or crooked tire.

Replace.
Replace.

Wobbly front wheel.

1. Distorted wheel rim.

2. Worn front wheel bearings.
3. Defective or incorrect tire.
4. Loose nut on axle.
5. Loose nuts on the rear shock.
6. Worn engine mounting bushing.
7. Loose nuts or bolts for engine mounting.

Replace.
Replace.
Replace.
Retighten.
Retighten.
Replace.
Tighten.

Front suspension
too soft.

1. Weakened springs.
2. Oil leakage of shock absorber.

Replace.
Replace.

Front suspension
too stiff.

1. Not enough grease.

2. Worn suspension arm spacer.

Refill.
Replace.

Noisy front
suspension.

1. Not enough grease.

2. Loose nuts on suspension.

Refill.
Retighten.

Wobbly rear wheel.

1. Distorted wheel rim.

2. Defective or incorrect tire.
3. Loose nuts on the rear shock absorber.
4. Worn engine mounting bushing.
5. Loose nuts or bolts for engine mounting.

Replace.
Replace.
Replace.
Replace.
Retighten.

Rear suspension
too soft.

1. Weakened spring.
2. Oil leakage of rear shock absorber.

Replace.
Replace.

Noisy rear
suspension.

1. Loosen nuts on shock absorber.

2. Worn engine mounting bushing.

Retighten.
Replace.

BRAKES
Complaint

Symptom and possible causes

Remedy

Insufficient brake
power.

1. Leakage of brake fluid from hydraulic system.

2. Worn pad.
3. Oil adhesion on engaging surface of pad.
4. Worn disc.
5. Air entered into hydraulic system.
6. Worn shoe.
7. Friction surfaces of shoes are dirty with oil.
8. Excessively worn drum.
9. Too much brake lever play.

Repair or replace.
Replace.
Clean disc and pads.
Replace.
Bleed air.
Replace.
Replace.
Replace.
Adjust.

Brake squeaking.

1. Carbon adhesion on pad surface.

2. Tilted pad.
3. Damaged wheel bearing.
4. Worn pad.
5. Foreign substance entered into brake fluid.
6. Clogged return ports of master cylinder.
7. Brake shoe surface glazed.
8. Loose front-wheel axle or rear-wheel axle nut.
9. Worn shoe.

Repair surface with sandpaper.

Modify and fitting.
Replace.
Replace.
Replace brake fluid.
Disassemble and clean master cylinder.
Repair surface with sandpaper.
Tighten to specified torque.
Replace.

7-5 SERVICING INFORMATION

Complaint
Excessive brake
lever stroke.

Symptom and possible causes

1. Air entered into hydraulic system.
2. Insufficient brake fluid.

Remedy

3. Improper quality of brake fluid.

4. Worn brake cam lever.
5. Excessively worn shoes and/or drum.

Bleed air.
Replenish fluid to normal lever;bleed
air.
Replace with correct fluid.
Replace.
Replace.

Leakage of brake
fluid.

1. Insufficient tightening of connection joints.

2. Cracked hose.
3. Worn piston seal.

Tighten to specified torque.

Replace.
Replace.

Brake drags.

1. Rusty moving parts.

Clean and lubricate.

SERVICING INFORMATION 7-6

SPECIAL TOOLS
Special tools

Part NumberPart NameDescription

09900-00401
Ltype hexagon wrench set

Special tools

Part NumberPart NameDescription

09900-20205
Micrometer
(1/100mm, 0-25mm)

Tighten hexagon bolt

Measure outside diameter of piston pin

09900-00410
Hexagon wrench set

09900-20508
Cylinder gauge set
(1/100mm, 40-80mm)

Tighten hexagon bolt

Measure inside diameter of cylinder

09900-05108
Snap ring pliers

09900-20602
Dial gauge
(1/100mm, 1mm)

Circlip remove and remounting

Measure inside diameter of cylinder

09900-06105
Snap ring pliers

09900-20605
Dial calipers
(1/100mm, 10-34mm)

Circlip remove and remounting

Measure width of conrod big-end

09900-06107
Snap ring pliers

09900-20606
Dial gauge
(1/100mm, 10mm)

Circlip remove and remounting

Measure run-out of wheel

09900-09003

09900-20701

Impact driver set

Magnetic stand

Remove and remounting of fixed screw

Used with Dial gauge

09900-20102

09900-20806

Vernier calipers

Thickness gauge

Measure thickness

Measure clearance of piston ring

09900-20202
Micrometer
(1/100mm, 25-50mm)

09900-21304

Measure height of cam

Used with Magnetic stand

09900-20203
Micrometer
(1/100mm, 50-75mm)

09900-21602

Measure outside diameter of piston

V-block set

CCI Oil gauge

A gauge to inspect performance of oil pump

7-7 SERVICING INFORMATION

Special tools

Part NumberPart NameDescription

Special tools

Part NumberPart NameDescription

09900-22301

09913-60710

Plastic gauge

Bearing remover

Measure clearance of crankshaft thrust

Remove bearing with the rotor remove sliding shaft

09900-22401
Small bore gauge
(10-18mm)

09913-75520

Measure inside diameter of conrod small-end

Used to drive bearing in

09900-25002

09913-75821

Pocket tester

Bearing installer

Measure voltage, electric current, resistance

Used to drive bearing in

09900-26006

09913-75830

Tachometer

Bearing installer

Measure rotational frequency of engine

Install rear axle shaft oil seal

09900-28107

09913-76010

Electro tester

Bearing installer

Inspect ignition coil

Install crankshaft bearing

09910-20115

09915-63310

Conrod holder

Compression gauge adapter

Used to lock the crankshaft

Used with compression gauge

09910-32812

09915-64510

Crankshaft installer

Compression gauge

Used to install the crankshaft in the crankcase

Measure cylinder compression

09913-14541

09916-84511

Fuel level gauge set

Tweezers

Measure height of carburetor

Remove and remounting valve cotter pin.

09913-50121

09920-13120

Oil seal remover

Crankcase separater

Used to remove the oil seal

Seprate to crankcase

Bearing installer

SERVICING INFORMATION 7-8

Special tools

Part NumberPart NameDescription

Special tools

Part NumberPart NameDescription

09921-20200

09930-30163

Bearing remover (10mm)

Rotor remover

Remove oil seal or bearing

Attached to the top of sliding shaft when removing rotor

09921-20210

09930-32420

Bearing remover (12mm)

Rotor holder

Remove oil seal or bearing

Remove and remounting rotor

09922-55131

09930-40113

Bearing installer

Rotor holder

Used to drive bearing in

Widely used to lock rotary parts such as a flywheel magneto

09923-73210

09940-10122

Bearing remover (17mm)

Clamp wrench

Remove bearing with the rotor remove sliding shaft

A hook wrench to adjust the steering head of motorcycle

09923-74510

09940-34520

Bearing remover (20~35mm)

T-handle

Remove bearing with the rotor remove sliding shaft

Remove and remounting front fork oil cylinder

09924-84521

09940-34561

Bearing installer

Front fork assembling tool attachmentD

Used to drive small bearing in

Used with T-handle

09925-98221

09940-50113

Bearing installer

Front fork oil seal installer

Used to drive bearing in

Install front fork oil seal

09930-10121

09941-34513

Spark plug socket wrench set

Bearing installer

Remove and remounting spark plug

Install steering outer race

09930-30102

09941-50110

Rotor remove sliding shfat

Wheel bearing remover

Used to with bearing remover or rotor remover

Remove wheel bearing

7-9 SERVICING INFORMATION

Special tools

Part NumberPart NameDescription

09943-74111
Front fork oil level gauge
Used to drain the fork oil to the specified level
09943-88211
Bearing remover
Remove rear axle shaft bearing
09951-76010
Bearing installer
Used to drive bearnig in

SERVICING INFORMATION 7-10

TIGHTENING TORQUE
ENGINE
Nm

kgm

Magneto rotor nut

35 ~ 45

3.5 ~ 4.5

Muffler mounting bolt

18 ~ 28

1.8 ~ 2.8

Exhaust pipe nut

8 ~ 12

0.8 ~ 1.2

Spark plug

25 ~ 30

2.5 ~ 3.0

Cylinder head nut

8 ~ 12

0.8 ~ 1.2

Engine mounting bolt

40 ~ 60

4.0 ~ 6.0

Engine mounting bracket bolt

48 ~ 72

4.8 ~ 7.2

Oil drain plug

9 ~ 15

0.9 ~ 1.5

Oil level bolt

9 ~ 15

0.9 ~ 1.5

Oil pump bolt

3~5

0.3 ~ 0.5

Clutch shoe nut

40 ~ 60

4.0 ~ 6.0

Clutch housing nut

40 ~ 60

4.0 ~ 6.0

Kick starter driven nut

40 ~ 60

4.0 ~ 6.0

Kick starter lever bolt

8 ~ 12

0.8 ~ 1.2

ITEM

7-11 SERVICING INFORMATION

CHASSIS
ITEM

Nm

kgm

Rear brake cam lever bolt

6~9

0.6 ~ 0.9

Rear shock absorber bolt

22 ~ 35

2.2 ~ 3.5

Rear axle nut

60 ~ 90

6.0 ~ 9.0

Steering stem lock nut

60 ~ 100

6.0 ~ 10.0

Front brake disc bolt

18 ~ 28

1.8 ~ 2.8

Front brake master cylinder bolt

8 ~ 12

0.8 ~ 1.2

Front brake air bleeder valve

6~9

0.6 ~ 0.9

Front brake caliper mounting bolt

18 ~ 28

1.8 ~ 2.8

Front brake hose union bolt

20 ~ 25

2.0 ~ 2.5

Front axle nut

33 ~ 52

3.3 ~ 5.2

Front fork bolt

35 ~ 55

3.5 ~ 5.5

Handlebar set bolt

22 ~ 28

2.2 ~ 2.8

Handlebar clamp nut

48 ~ 52

4.8 ~ 5.2

TIGHTENING TORQUE CHART

For other bolts and nuts whos torque is not listed, refer to this chart :

Bolt Diameter
(mm)

Conventional or4marked bolt

7marked bolt

Nm

kgm

Nm

kgm

1.0 ~ 2.0

0.1 ~ 0.2

1.5 ~ 3.0

0.15 ~ 0.3

2.0 ~ 4.0

0.2 ~ 0.4

3.0 ~ 6.0

0.3 ~ 0.6

4.0 ~ 7.0

0.4 ~ 0.7

8.0 ~ 12.0

0.8 ~ 1.2

10.0 ~ 16.0

1.0 ~ 1.6

18.0 ~ 28.0

1.8 ~ 2.8

10

22.0 ~ 35.0

2.2 ~ 3.5

40.0 ~ 60.0

4.0 ~ 6.0

12

35.0 ~ 55.0

3.5 ~ 5.5

70.0 ~ 100.0

7.0 ~ 10.0

14

50.0 ~ 80.0

5.0 ~ 8.0

110.0 ~ 160.0

11.0 ~ 16.0

16

80.0 ~ 130.0

8.0 ~ 13.0

170.0 ~ 250.0

17.0 ~ 25.0

18

130.0 ~ 190.0

13.0 ~ 19.0

200.0 ~ 280.0

20.0 ~ 28.0

SERVICING INFORMATION 7-12

SERVICE DATA
CYLINDER + PISTON + PISTON RING

Unit : mm

ITEM

STANDARD

LIMIT

0.065 ~ 0.075

0.120

Cylinder bore

41.005 ~ 41.020

41.07

Piston diam.

40.935 ~ 40.950
Measure at 15mm from the skirt end

40.885

Piston to cylinder clearance

Cylinder distortion

0.1

Cylinder head distortion

0.1

Piston ring clearance

(Free condition)
Piston ring clearance
(Assembling condition)
Piston ring - ring groove clearance

1st

Approx. 4.5

3.2

2nd

Approx. 4.3

3.1

1st

0.10 ~ 0.25

0.75

2nd

0.10 ~ 0.25

0.75

1st

0.02 ~ 0.06

2nd

0.02 ~ 0.06

Piston pin bore I.D

10.002 ~ 10.010

10.030

Piston pin O.D

9.995 ~ 10.000

9.980

CONROD + CRANKSHAFT
ITEM
Conrod small end I.D.

Unit : mm
STANDARD

LIMIT

14.003 ~ 14.011

14.047

Conrod big end runout

Crank web to wed width
Crankshaft runout

3.0
35 0.1
0.08

7-13 SERVICING INFORMATION

OIL PUMP

Unit : mm
ITEM

STANDARD

Oil pump reduction ratio

30.000(30/1)

CLUTCH

Unit : mm
ITEM

Clutch housing I.D.

Clutch shoe thickness

STANDARD

LIMIT

110.00 ~ 110.15

110.35

3.0

2.0

Clutch in rpm

3,600 200 rpm

Clutch tight rpm

6,000 200rpm

TRANSMISSION
ITEM
Final reduction ratio

Unit : mm
STANDARD
12.0

Gear ratios

2.997 ~ 0.813

V-belt width

16.5 0.6

V-belt thickness

8.0 0.6

Movable drive face spring free length

LIMIT

143.8

15.3

135 ~ 153

SERVICING INFORMATION 7-14

CARBURETOR

Unit : mm

ITEM

SPECIFICATION

Carburetor type

VM14

Main bore size

14

I.D. No.

HG 266

Idle rpm

1,800 50 rpm

Fuel level

24.5
(M.J.)

55

Main air jet

(M.A.J.)

1.0

Jet needle

(J.N.)

3E17-3

Needle jet

(N.J.)

E-2

Pilot jet

(P.J.)

25

Throttle valve

(T.V.)

3.0

By-pass

(B.P.)

2.4 0.05

Valve seat

(V.S.)

1.2

Stater jet

(G.S.)

25

Pilot screw

(P.S.)

Pilot outlet

(P.O.)

Main jet

Throttle cable play

0.8
0.5 ~ 1.0

7-15 SERVICING INFORMATION

ELECTRICAL

Unit : mm

ITEM

SPECIFICATION

Ignition timing

20at 1,000 rpm

Spark plug

Type

BR8HSA

Gap

0.6 ~ 0.7
Over 8 mm

Spark performance
Primary

0.19 ~ 0.24

Secondary

5.4 ~ 6.6

Lighting coil

0.54 ~ 0.80

Y/W-Ground

Charging coil

0.69 ~ 1.03

W/R-Ground

Exciting coil

220 ~ 260

B/R-Ground

Pick-up coil

90 ~ 110

Br-W

Ignition coil resistance

Stator coil resistance

Regulated voltage
No-load performance of A.C. generator
Starter relay resistance

Battery

NOTE

13.0 ~ 16.0 V at 5,000 rpm

More than 17V (at 5,000 rpm)
0 ~ 70

Type designation

YT4L-BS

Capacity

12V, 3AH

Standard electrolyte S.G.

Fuse

1.32 at 20 (68)
10 A

WATTAGE

Unit : W
ITEM

Head lamp bulb

SPECIFICATION
15W 2

Tail/Brake lamp bulb

5 / 10W

Turn signal lamp bulb

10W 4

Turn signal / Oil level check light pilot lamp

Speedometer lamp bulb
CAUTION

Do not use except the specified bulb (Wattage).

1.7W / 17W
1.7W 2

SERVICING INFORMATION 7-16

BRAKE+WHEEL

Unit : mm

ITEM

LIMIT

STANDARD
Front

5 ~ 20

Rear

15 ~ 25

Brake drum I.D

Rear

100

100.7

Brake lining thickness

Rear

99.2

96

Brake disc plate thickness

Front

4.0 0.2

3.5

Brake disc plate runout

Front

Master cylinder bore I.D.

Front

11.000 ~ 11.043

11.055

Master cylinder piston diam.

Front

10.957 ~ 10.984

10.945

Brake caliper I.D.

Front

30.230 ~ 30.306

30.315

Brake caliper piston diam.

Front

30.150 ~ 30.200

30.140

Brake lever play

Wheel rim runout

Axle shaft runout
Tire size

Tire tread depth

0.30

Axial

3.0

Radial

3.0

Front

0.25

Front

110/70-12 47J

Rear

120/70-12 51J

Front

1.6

Rear

1.6

7-17 SERVICING INFORMATION

SUSPENSION

Unit: mm
STANDARD

ITEM
Front fork stroke

LIMIT

75

Front fork spring length(Free condition)

290.9

Front fork oil specification

TELLUS # 37

Front fork oil capacity(One side)

50 cc

Rear wheel travel

66

TIRE PRESSURE
DUAL RIDING

SOLO RIDING

COLD INFLATION
TIRE PRESSURE

kPa

kg/

kPa

kg/

FRONT

123

1.25

172

1.75

REAR

196

2.00

221

2.25

FUEL + OIL
ITEM
Fuel type

SPECIFICATION
Gasoline used should be graded 85 ~ 95 octane or higher.
An unleaded gasoline is recommended.
4.8

Fuel tank capacity

APOLLOIL BIKE-K, HYPOL HS

Engine oil type

1.0

Engine oil capacity

1.0 ~ 1.2
(at 3,000 rpm for 5 minutes)

Engine oil discharge amount

Transmission oil type

SAE 10W/30 or 10W/40 multi-grade motor oil

Replace

110

Overhaul

130

Transmission oil capacity

Brake fluid type

NOTE

DOT 4

I.D 60/Hr
F.O 100/Hr

SERVICING INFORMATION 7-18

WIRE AND CABLE ROUTING

REAR BRAKE
Rear turnsignal L

Battery cover

Rear turnsignal
R/L

Switch thermo

Starter relay

Fuse case
Rear turnsignal R

09407-22402
Lamp assy, Tail & Stop
Rear turnsignal R/L

09407-22402
Starter motor
magneto

09407-22402
Clamp

Engine earth

Ignition coil

Rear brake
cable

Brake cable

Rear brake
cable

Throttle cable

Switch thermo

VIEW B

Front

Harness

Frame

P.T.C

Frame earth

VIEW D

Clamp

Harness

Steering lock

Fender, Front upper

Speedometer
cable

Harness

Head lamp

Front turnsignal RH/LH

Fuel tank

Speedometer cable

Front

Starter motor
magneto

Ignition coil

Rear brake cable

Engine earth

Helmet box

Master cylinder hose

Throttle cable

Starter motor

Starter motor

Shield leg lower rear

Heater carburetor

Harness

REAR TURNSIGNAL LAMP

Fuse case
Battery, ,
Oil level gauge

Oil tank 09407-22402

Rear fender
Shield leg lower rear

Rear turnsignal RH/LH

09407-22402

Lamp assy Tail & Stop

Rear turnsignal R/L

Lamp assy Tail & Stop couple

CABLE

VIEW C

Harness
Throttle cable
Brake cable

Brake
hose

Rear brake
cable

Throttle cable

Regulator

Regulator
Front turnsignal RH/LH
Head lamp

Horn

CDI unit

Turnsignal relay

Clamp

Harness

7-19 SERVICING INFORMATION

Head lmap
Lamp

Rear combination

Rear turnsignal
Front turnsignal
Oil pilot lamp
turnsignal pilot lamp
Illumination

DEST

Tail
Stop

Front turnsignal LH

Head lamp

Front turnsignal RH

5
10
152

10
10
1.7
1.7
1.72

Speedometer

Turnsignal

B
Br
G
Gr
L

: Black
: Brown
: Green
: Gray
: Blue

Lg
O
R
Sb
W

Ignition switch

Horn

: Light green
: Orange
: Red
: Light blue
: White

Y
BG
BW
BR
LW

Oil gauge
Regulator

: Yellow
: Black with Green tracer
: Black with White tracer
: Black with Red tracer
: Blue with White tracer

Spark plug

RB
RW
WB
WR
YB

Battery

Engine earth

Rear turnsignal LH

Tail & Stop

Rear turnsignal RH

Carburetor, Heater
Thermo switch
P.T.C

: Red with Black tracer

: Red with White tracer
: White with Black tracer
: White with Red tracer
: Yellow with Black tracer

Starter motor

Ignition coil Starter relay

Fuel gauge
Frame earth

C.D.I unit

Turnsignal relay

Rear brake Magneto

switch

Front brake switch

WIRE COLOR

Handle switch LH

Horn

Lighting

Handle switch RH

Starter

SERVICING INFORMATION 7-20

WIRING DIAGRAM

Prepared by

HYOSUNG MOTORS & MACHINERY INC.

2nd Ed. NOV. 1999

Manual No. 99000-91310
Printed in Korea