YFM350S 3GD-AE7

SUPPLEMENTARY
SERVICE MANUAL
 FOREWORD

This Supplementary Service Manual has been prepared to introduce new service and data for the
YFM350S. For complete service information procedures it is necessary to use this Supplementary
Service Manual together with the following manual.

YFM350X(J) ’97 SERVICE MANUAL: 3GD-AE5

YFM350X(P) 2002 SUPPLEMENTARY SERVICE MANUAL: 3GD-AE6

YFM350S
SUPPLEMENTARY
SERVICE MANUAL
©2004 by Yamaha Motor Co., Ltd.
First edition, January 2004
All rights reserved.
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.
EBS00002

NOTICE
This manual was produced by the Yamaha Motor Company primarily for use by Yamaha dealers
and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one
manual, so it is assumed that anyone who uses this book to perform maintenance and repairs on
Yamaha machine has a basic understanding of the mechanical ideas and the procedures of
machine repair. Repairs attempted by anyone without this knowledge are likely to render the
machine unsafe and unfit for use.

Yamaha Motor Company, Ltd. is continually striving to improve all its models. Modifications and sig-
nificant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers
and will appear in future editions of this manual where applicable.

NOTE:
_

Designs and specifications are subject to change without notice.

EBS00003

IMPORTANT INFORMATION
Particularly important information is distinguished in this manual by the following notations.
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR
SAFETY IS INVOLVED!
WARNING Failure to follow WARNING instructions could result in severe injury or death
to the machine operator, a bystander or a person checking or repairing the
machine.
CAUTION: A CAUTION indicates special precautions that must be taken to avoid dam-
age to the machine.
NOTE: A NOTE provides key information to make procedures easier or clearer.
EBS00004

HOW TO USE THIS MANUAL

MANUAL ORGANIZATION
This manual consists of chapters for the main categories of subjects. (See “symbols”)
1st title 1: This is the title of the chapter with its symbol in the upper right corner of each page.
2nd title 2: This title indicates the section of the chapter and only appears on the first page of each
section. It is located in the upper left corner of the page.
3rd title 3: This title indicates a sub-section that is followed by step-by-step procedures accompa-
nied by corresponding illustrations.
EXPLODED DIAGRAMS
To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each
removal and disassembly section.
1. An easy-to-see exploded diagram 4 is provided for removal and disassembly jobs.
2. Numbers 5 are given in the order of the jobs in the exploded diagram. A number that is enclosed
by a circle indicates a disassembly step.
3. An explanation of jobs and notes is presented in an easy-to-read way by the use of symbol marks
6. The meanings of the symbol marks are given on the next page.
4. A job instruction chart 7 accompanies the exploded diagram, providing the order of jobs, names
of parts, notes in jobs, etc.
5. For jobs requiring more information, the step-by-step format supplements 8 are given in addition
to the exploded diagram and the job instruction chart.
 EB003000
1 2 ILLUSTRATED SYMBOLS
GEN Illustrated symbols 1 to 8 are printed on the

INFO SPEC top right of each page and indicate the subject
of each chapter.
3 4
1 General information
2 Specifications
CHK 3 Periodic checks and adjustments
ADJ ENG 4 Engine
5 Carburetion
5 6 6 Chassis
7 Electrical
8 Troubleshooting
CARB CHAS
7 8

ELEC – + TRBL
SHTG
9 0 Illustrated symbols 9 to E are used to identify
the specifications appearing in the text.
9 Filling fluid
0 Lubricant
A Special tool
A B B Torque
C Wear limit, clearance
D Engine speed
T.
R.

E Ω, V, A

C D

Illustrated symbols F to L in the exploded

F G H
diagrams indicate the types of lubricants and
lubrication points.
E G M F Apply engine oil
G Apply gear oil
I J K L H Apply molybdenum disulfide oil
I Apply wheel bearing grease
B LS M S J Apply lightweight lithium soap base grease
K Apply molybdenum disulfide grease
L Apply silicon grease
M N Illustrated symbols M to N in the exploded
diagrams indicate where to apply a locking

LT
New agent M and when to install a new part N.
M Apply the locking agent (LOCTITE®)
N Replace
 CONTENTS

GENERAL INFORMATION ................................................................................ 1

MACHINE IDENTIFICATION ....................................................................... 1
MODEL LABEL ...................................................................................... 1
SPECIAL TOOLS ......................................................................................... 2

SPECIFICATIONS .............................................................................................. 3
GENERAL SPECIFICATIONS ..................................................................... 3
MAINTENANCE SPECIFICATIONS ............................................................ 5
ENGINE ................................................................................................. 5
CHASSIS ............................................................................................... 7
ELECTRICAL ....................................................................................... 10
CABLE ROUTING ...................................................................................... 11

PERIODIC CHECKS AND ADJUSTMENTS.................................................... 23

INTRODUCTION ........................................................................................ 23
PERIODIC MAINTENANCE/LUBRICATION.............................................. 23
SEAT, FENDERS AND FUEL TANK.......................................................... 25
SEAT, SIDE COVERS, AND FRONT PANEL ..................................... 25
FOOT PROTECTORS, ENGINE SKID PLATE,
AND FRONT BUMPER....................................................................... 26
HEADLIGHTS AND FRONT FENDER ................................................ 27
REAR FENDER ................................................................................... 28
FUEL TANK ......................................................................................... 30
CHASSIS.................................................................................................... 32
CHECKING THE FRONT BRAKE PADS............................................. 32
ADJUSTING THE PARKING BRAKE .................................................. 32
ADJUSTING THE REAR SHOCK ABSORBER................................... 33
ELECTRICAL SYSTEM.............................................................................. 35
CHECKING AND CHARGING THE BATTERY ................................... 35
ADJUSTING THE HEADLIGHT BEAMS ............................................. 40
REPLACING A HEADLIGHT BULB ..................................................... 41

ENGINE ............................................................................................................ 42
ENGINE REMOVAL ................................................................................... 42
INSTALLING THE ENGINE ................................................................. 42
CLUTCH ..................................................................................................... 43
INSTALLING THE RIGHT CRANKCASE COVER............................... 43

CARBURETOR................................................................................................. 44
CARBURETOR .......................................................................................... 44
CHASSIS .......................................................................................................... 47
REAR WHEELS AND REAR AXLE HUB ................................................... 47
REMOVING THE REAR AXLE ............................................................ 49
INSTALLING THE REAR AXLE........................................................... 50
FRONT ARMS AND FRONT SHOCK ABSORBER ................................... 51
REAR BRAKE ............................................................................................ 53
ASSEMBLING THE REAR BRAKE CALIPER ..................................... 53
REAR SHOCK ABSORBER AND SWINGARM ......................................... 54
HANDLING THE REAR SHOCK ABSORBER
AND GAS CYLINDER......................................................................... 56
DISPOSING OF THE REAR SHOCK ABSORBER
AND GAS CYLINDER......................................................................... 56

ELECTRICAL ................................................................................................... 57
ELECTRICAL COMPONENTS................................................................... 57

YFM350S WIRING DIAGRAM

 GEN
MACHINE IDENTIFICATION INFO
GENERAL INFORMATION
MACHINE IDENTIFICATION
MODEL LABEL
The model label 1 is affixed to the frame. This
information will be needed to order spare
parts.

–1–
 GEN
SPECIAL TOOLS INFO
EB102001

SPECIAL TOOLS
The following special tools are necessary for complete and accurate tune-up and assembly. Use
only the appropriate special tools; this will help prevent damage caused by the use of inappropriate
tools or improvised techniques. Special tools may differ by shape and part number from country to
country. In such a case, two types are provided.
When placing an order, refer to the list provided below to avoid any mistakes.
For US and CDN
P/N. YM-, YU-, YS-, YK-, ACC-
Except for US and CDN
P/N. 90890-

Tool No. Tool name/How to use Illustration

Steering nut wrench

90890-01443
YU-33975
This tool is needed to loosen and tighten
the rear shock absorber locknut.
Axle nut wrench (46 mm)

90890-01498
YM-37134
This tool is needed to loosen or tighten
the rear axle nut.

–2–
 GENERAL SPECIFICATIONS SPEC
SPECIFICATIONS
GENERAL SPECIFICATIONS
Model YFM350S
Model code number 5YT1 (For USA and Oceania)
5YT2 (For CDN)
5YT3 (For Europe)
Dimensions
Overall length 1,770 mm (69.7 in)
Overall width 1,095 mm (43.1 in)
Overall height 1,080 mm (42.5 in)
Seat height 820 mm (32.3 in)
Wheelbase 1,210 mm (47.6 in)
Minimum ground clearance 115 mm (4.53 in)
Basic weight
With oil and full fuel tank 180.0 kg (397 lb)
Minimum turning radius 3,100 mm (122 in)
Engine
Engine type Air-cooled 4-stroke, SOHC
Cylinder arrangement Forward-inclined single cylinder
Displacement 349.0 cm3 (21.30 cu.in)
Bore × stroke 83.0 × 64.5 mm (3.27 × 2.54 in)
Compression ratio 9.20 : 1
Compression pressure 850 kPa (8.5 kg/cm2, 120.9 psi) at 350 r/min
Starting system Electric starter
Oil capacity
Engine oil
Periodic oil change 2.50 L (2.20 Imp qt, 2.64 US qt)
With oil filter replacement 2.60 L (2.29 Imp qt, 2.75 US qt)
Total amount 3.20 L (2.82 Imp qt, 3.38 US qt)
Fuel
Type Regular unleaded gasoline only
(For CDN and Europe)
Unleaded gasoline only (For USA and Oceania)
Tank capacity 9.0 L (1.98 Imp gal, 2.38 US gal)
Reserve amount 2.7 L (0.59 Imp gal, 0.71 US gal)
Carburetor
Type/manufacturer BSR36/MIKUNI

–3–
 GENERAL SPECIFICATIONS SPEC
Model YFM350S
Transmission
Primary reduction system Spur gear
Primary reduction ratio 76/24 (3.167)
Secondary reduction system Chain drive
Secondary reduction ratio 38/13 (2.923)
Transmission type Constant mesh, 6-speed forward, 1-speed
reverse
Operation Left foot operation
Gear ratio 1st 36/16 × 20/27 × 29/18 (2.685)
2nd 33/20 × 20/27 × 29/18 (1.969)
3rd 29/23 × 20/27 × 29/18 (1.504)
4th 27/26 × 20/27 × 29/18 (1.239)
5th 25/28 × 20/27 × 29/18 (1.066)
6th 23/29 × 20/27 × 29/18 (0.946)
Reverse 33/16 × 33/10 (6.806)
Chassis
Frame type Steel tube frame
Caster angle 6°
Trail 26.0 mm (1.02 in)
Toe-in (unloaded) 20 ~ 30 mm (0.79 ~ 1.18 in)
Tires
Type Tubeless
Size front AT21 × 7-10
rear AT20 × 10-9
Manufacturer front DUNLOP
rear DUNLOP
Type front KT851B
rear KT877A
Brakes
Front brake type Dual disc brake
operation Right hand operation
Rear brake type Single disc brake
operation Right foot operation
Electrical
Ignition system DC C.D.I.
Generator system A.C. magneto
Battery voltage/capacity 12 V/8.6 Ah
Battery type YTZ10S
Bulb wattage × quantity
Headlight 12 V 30 W/30 W × 2
Tail/brake light 12 V 5 W/21 W × 1
Neutral indicator light 12 V 1.7 W × 1
Reverse indicator light 12 V 1.7 W × 1

–4–
 MAINTENANCE SPECIFICATIONS SPEC
MAINTENANCE SPECIFICATIONS
ENGINE

Model YFM350S
Rocker arm/rocker arm shaft
Rocker arm inside diameter 11.980 ~ 11.998 mm (0.4717 ~ 0.4724 in)
Rocker arm shaft outside diameter 11.961 ~ 11.971 mm (0.4709 ~ 0.4713 in)
Rocker-arm-to-rocker-arm-shaft clearance 0.009 ~ 0.037 mm (0.0004 ~ 0.0015 in)
Carburetor
I.D. mark 5YT1 00
Main jet (M.J) #142.5
Main air jet (M.A.J) #35
Jet needle (J.N) 5JFC39-2
Needle jet (N.J) P-0M
Pilot jet (P.J) #22.5
Pilot air jet (P.A.J.1) #65
(P.A.J.2) #165
Pilot outlet (P.O) 1
Bypass 1 (B.P.1) 0.8
Bypass 2 (B.P.2) 0.8
Bypass 3 (B.P.3) 0.8
Pilot screw turns out (P.S) 2-1/4 (For CDN, Europe, and Oceania)
Valve seat (V.S) 2.5
Starter jet (G.S) #70
Throttle valve size (Th.V) #105
Fuel level (F.L) 4 ~ 5 mm (0.16 ~ 0.20 in)
Above the float chamber mating surface
Float height 13.0 mm (0.51 in)
Engine idling speed 1,450 ~ 1,550 r/min
Intake vacuum 33.3 kPa (250 mmHg, 9.83 inHg)

–5–
 MAINTENANCE SPECIFICATIONS SPEC
Tightening torques

Thread Tightening torque

Part to be tightened Part name Q’ty Remarks
size Nm m · kg ft · lb
Carburetor joint Bolt M8 2 20 2.0 14
Carburetor clamp (cylinder head side) Screw M4 1 3 0.3 2.2
Carburetor clamp (air filter case side) Screw M4 1 3 0.3 2.2
Air filter case Screw M4 1 3 0.3 2.2
Muffler and exhaust pipe Bolt M8 1 16 1.6 11
Muffler Bolt M8 2 34 3.4 24
Clutch cable holder Bolt M8 1 16 1.6 11
Right crankcase cover Bolt M6 15 10 1.0 7.2
Left crankcase cover Bolt M6 9 11 1.1 8.0
Crankshaft end cover Bolt M6 4 7 0.7 5.1
Bearing retainer (balancer shaft) Screw M6 2 7 0.7 5.1
Bearing retainer (main axle) Screw M6 2 7 0.7 5.1
Bearing retainer (left crankcase) Screw M5 2 7 0.7 5.1
Use a lock
Drive sprocket Nut M20 1 90 9.0 65
washer.
Stopper lever Bolt M6 1 10 1.0 7.2
Reverse shift cam stopper bolt Bolt M14 1 18 1.8 13
Drive select lever assembly Bolt M8 2 20 2.0 14
Drive select lever shift rod and
Bolt M6 1 16 1.6 11
reverse shift cam
Shift rod (shift pedal) locknut Nut M6 2 8 0.8 5.8

–6–
 MAINTENANCE SPECIFICATIONS SPEC
CHASSIS

Model YFM350S
Steering system
Lock-to-lock angle
Left 42.5°
Right 42.5°
Front suspension
Shock absorber stroke 90.0 mm (3.54 in)
Shock absorber spring free length 232.5 mm (9.15 in)
Spring rate (K1) 32.00 N/mm (3.26 kg/mm, 182.72 lb/in)
(K2) 45.00 N/mm (4.59 kg/mm, 256.95 lb/in)
Spring stroke (K1) 0 ~ 45.0 mm (0 ~ 1.77 in)
(K2) 45.0 ~ 90.0 mm (1.77 ~ 3.54 in)
Optional spring No
Rear suspension
Shock absorber stroke 88.0 mm (3.46 in)
Shock absorber spring free length 238.5 mm (9.39 in)
Spring rate (K1) 57.00 N/mm (5.81 kg/mm, 325.46 lb/in)
Stroke 0 ~ 88.0 mm (0 ~ 3.46 in)
Enclosed gas pressure (standard) 1,500 kPa (15.0 kg/cm2, 213.3 psi)
(Min) 1,450 kPa (14.5 kg/cm2, 206.2 psi)
(Max) 1,550 kPa (15.5 kg/cm2, 220.4 psi)
Wheel
Front wheel type Panel wheel
Rear wheel type Panel wheel
Front rim size/material 10 × 5.5 AT/Aluminum
Rear rim size/material 9 × 8.5 AT/Aluminum
Rim runout limit
Vertical <2.0 mm (0.08 in)>
Lateral <2.0 mm (0.08 in)>
Front disc brake
Type Dual disc brake
Disc outside diameter × thickness 161.0 × 3.5 mm (6.34 × 0.14 in)
<Limit> <3.0 mm (0.12 in)>
Pad thickness 4.2 mm (0.17 in)
<Limit> <1.0 mm (0.04 in)>
Rear disc brake
Type Single disc brake
Disc outside diameter × thickness 200.0 × 3.6 mm (7.87 × 0.14 in)
<Limit> <3.1 mm (0.12 in)>
Pad thickness 4.5 mm (0.18 in)
<Limit> <1.0 mm (0.04 in)>

–7–
 MAINTENANCE SPECIFICATIONS SPEC
Model YFM350S
Brake lever and brake pedal
Brake lever free play 0 mm (0 in)
Brake pedal position 50.2 mm (1.98 in)
From the top of the frame to the top of the brake
pedal
Throttle lever free play 2 ~ 4 mm (0.08 ~ 0.16 in)
Drive chain
Type/manufacturer DID520V/DAIDO
Number of links 97 + 1 links
Chain free play 25.0 ~ 35.0 mm (0.98 ~ 1.38 in)

Tightening torques

Tightening torque
Part to be tightened Thread size Remarks
Nm m · kg ft · lb
Engine and frame M10 73 7.3 53
Front shock absorber and frame M10 48 4.8 35
Front shock absorber and lower arm M10 48 4.8 35
Steering knuckle and front wheel hub M14 70 7.0 50
Steering shaft and frame M10 35 3.5 25
Tie-rod locknut M10 15 1.5 11
Disc cover (inner) M6 7 0.7 5.1
Front brake master cylinder M6 7 0.7 5.1
Clutch and parking brake lever assembly M5 4 0.4 2.9
Front brake hose and upper front arm M6 7 0.7 5.1
Front brake pipe and brake pipe joint M10 19 1.9 13
Brake pipe joint and frame M6 10 1.0 7.2
Brake caliper bleed screw M8 6 0.6 4.3
Rear brake hose union bolt M10 28 2.8 20
Parking brake adjusting bolt and locknut M8 16 1.6 11
Rear brake light switch bracket and frame M6 7 0.7 5.1
Rear brake master cylinder and frame M8 23 2.3 17
Rear brake fluid reservoir and frame M6 7 0.7 5.1
Rear brake hose and swingarm M6 7 0.7 5.1
Rear hub and rear brake caliper M8 34 3.4 24
Rear axle ring nut M33 160 16.0 115 LT

Rear axle ring nut set bolt M6 7 0.7 5.1 LT

Rear hub and swingarm (lower) M10 73 7.3 53

Rear shock absorber and frame M12 80 8.0 58
Relay arm and swingarm M12 73 7.3 53
Rear shock absorber and relay arm M12 73 7.3 53
Connecting rod and relay arm M12 73 7.3 53
Connecting rod and frame M12 73 7.3 53
Spring preload adjusting locknut (rear shock
M44 42 4.2 30
absorber)

–8–
 MAINTENANCE SPECIFICATIONS SPEC
Tightening torque
Part to be tightened Thread size Remarks
Nm m · kg ft · lb
Swingarm guard and swingarm M8 16 1.6 11
Driven chain sprocket and boss M10 55 5.5 40
Front bumper M8 12 1.2 8.7
Rear bumper M8 34 3.4 24
Drive chain guard M8 12 1.2 8.7
Foot protectors (left and right) and frame M8 16 1.6 11
Foot protectors (left and right), rear fender stay
M8 17 1.7 12
and frame
Foot protectors (left and right) and footrest M8 17 1.7 12
Footrest and frame M10 73 7.3 53
Battery holder M6 10 1.0 7.2
Front fender and front fender bracket M6 7 0.7 5.1
Front fender and frame M6 7 0.7 5.1
Front fender bracket (center) and frame M6 10 1.0 7.2
Front fender brackets (left and right) and frame M6 13 1.3 9.4
Headlight bracket and front fender bracket M6 7 0.7 5.1
Rear fender and frame M6 10 1.0 7.2
Rear fender and rear bumper M6 7 0.7 5.1
Rear fender and rear fender stay M6 7 0.7 5.1
Rear fender stay and frame M6 7 0.7 5.1
Rear fender stay and frame M8 16 1.6 11
Engine skid plate and frame M8 12 1.2 8.7
Fuel tank M6 7 0.7 5.1
Fuel cock and fuel tank M6 4 0.4 2.9
Rectifier/regulator M6 7 0.7 5.1
Tail/brake light bracket and rear fender M6 4 0.4 2.9

–9–
 MAINTENANCE SPECIFICATIONS SPEC
ELECTRICAL

Model YFM350S
C.D.I.
Magneto model/manufacturer F4T466/MITSUBISHI
Pickup coil resistance 459 ~ 561 Ω at 20 °C (68 °F)
(Color) (White/Red-White/Green)
Rotor rotation direction detection coil resis- 0.083 ~ 0.101 Ω at 20 °C (68 °F)
tance
(Color) (Red-White/Blue)
C.D.I. unit-model/manufacturer F8T40374/MITSUBISHI
Rectifier/regulator
Regulator type Semi conductor-short circuit
Model/manufacturer SH640E-11/SHINDENGEN
No-load regulated voltage 14.1 ~ 14.9 V
Rectifier capacity 14 A
Withstand voltage 200 V
Starter relay
Model/manufacturer 2768095-A/JIDECO
Amperage rating 180 A
Coil winding resistance 4.18 ~ 4.62 Ω
Battery
Specific gravity 1.310 at 20 °C (68 °F)
Starter motor
Model/manufacturer DBQD5/DENSO
Output 0.7 kW
Armature coil resistance 0.0118 ~ 0.0133 Ω at 20 °C (68 °F)
Brush overall length 12 mm (0.47 in)
8.5 mm (0.33 in)
Brush spring pressure 6.38 ~ 9.32 N (651 ~ 950 gf, 22.96 ~ 33.55 oz)
Commutator diameter 28 mm (1.10 in)
27 mm (1.06 in)
Mica undercut 0.6 mm (0.024 in)

– 10 –
 CABLE ROUTING SPEC
CABLE ROUTING
1 Clutch switch lead 0 Handlebar switch lead
2 Starter cable
3 Clutch cable È Fasten the front brake light switch lead with two
4 Parking brake cable plastic bands.
5 Front brake hose É Fasten the starter cable, clutch switch lead, and
6 Front brake light switch lead handlebar switch lead with a plastic band.
7 Throttle cable Ê Fasten the clutch switch lead and handlebar
8 Neutral indicator light switch lead with a plastic band.
9 Reverse indicator light

3 4 5 6
1 2

Ê É 9 8 È
0 7

– 11 –
 CABLE ROUTING SPEC
1 Parking brake cable È Pass the clutch switch lead, handlebar switch
2 Clutch cable lead, neutral/reverse indicator light lead, front
3 Starter cable brake light switch lead, and starter cable through
4 Clutch switch lead the guide.
5 Handlebar switch lead É Fasten the clutch switch lead, handlebar switch
6 Neutral/reverse indicator light lead lead, neutral/reverse indicator light lead, and
7 Rectifier/regulator front brake light switch lead securely with a plas-
8 Front brake light switch lead tic locking tie.
9 Front brake hose
0 Throttle cable

1
2
3

0
9
8
4
5
6
È
É
Ê
Ë

– 12 –
 CABLE ROUTING SPEC
Ê Route the clutch switch lead, handlebar switch
lead, neutral/reverse indicator light lead, and
front brake light switch lead in front of the guide.
Ë Pass the throttle cable, clutch cable, and parking
brake cable to the right side of the steering shaft.

1
2
3

0
9
8
4
5
6
È
É
Ê
Ë

– 13 –
 CABLE ROUTING SPEC
1 Rectifier/regulator B Neutral switch lead
2 Ignition coil C Starter motor lead
3 Wire harness D Clutch cable
4 Starter cable E Parking brake cable
5 Fuel tank breather hose
6 Fuel hose
7 Carburetor air vent hose
8 Crankcase breather hose
9 Reverse switch lead
0 Negative battery lead
A Carburetor overflow hose

3
4
3
C
4 Ò
B-B
C 7 C
Ñ Ó
A-A
5 3
C-C
4
Ô
4
4 6
3
È 7É 3
2
1 Ê C
C D D-D
A B Ë
8

A B

C
D

Ì
9
0
E D C Ð Ï B Î A Í

– 14 –
 CABLE ROUTING SPEC
È Pass the parking brake cable and clutch cable Ì Fasten the A.C. magneto lead, neutral switch
through the cable guide. lead, reverse switch lead, and negative battery
É Pass the carburetor air vent hose through the lead with a plastic band. Face the end of the
hole in the fuel tank. plastic band inward.
Ê The end of the carburetor air vent hose should Í Pass the neutral switch lead and carburetor
extend at least 15 mm above the hole but not be overflow hose through the guide on the drive
higher than the intake of the air filter case. sprocket cover. Route the neutral switch lead
Ë Pass the clutch cable and parking brake cable behind the carburetor overflow hose.
between the carburetor overflow hose and Î Fasten the A.C. magneto lead with the holder.
crankcase breather hose.

3
4
3
C
4 Ò
B-B
C 7 C
Ñ Ó
A-A
5 3
C-C
4
Ô
4
4 6
3
È 7É 3
2
1 Ê C
C D D-D
A B Ë
8

A B

C
D

Ì
9
0
E D C Ð Ï B Î A Í

– 15 –
 CABLE ROUTING SPEC
Ï Fasten the parking brake cable and clutch cable Ò Pass a plastic band through the hole in the fuel
with the clip. Fasten the clip to the clutch cable tank shield, and then fasten the wire harness,
between the cable protector and the clutch cable starter motor lead, and starter cable with the
adjuster. plastic band. The end of the plastic band should
Ð Pass the parking brake cable and clutch cable be under the frame, facing inward.
through the cable guide. Ó Route the wire harness and starter motor lead
Ñ Fasten the wire harness, starter motor lead, and above the starter cable.
starter cable with a plastic band. Face the end of Ô Fasten the wire harness and starter motor lead
the plastic band down. with a plastic band. Face the end of the plastic
band inward.

3
4
3
C
4 Ò
B-B
C 7 C
Ñ Ó
A-A
5 3
C-C
4
Ô
4
4 6
3
È 7É 3
2
1 Ê C
C D D-D
A B Ë
8

A B

C
D

Ì
9
0
E D C Ð Ï B Î A Í

– 16 –
 CABLE ROUTING SPEC
1 Tail/brake light lead È Pass the wire harness, negative battery lead,
2 Battery and starter motor lead through the hole in the
3 C.D.I. unit rear fender.
4 Wire harness É More than 15 mm (0.6 in)
5 Starter motor lead
6 Negative battery lead
7 Carburetor air vent hose
8 Positive battery lead
9 Starter relay
0 Starting circuit cut-off relay

8 9 1

5
5 6
4 7
6
0
3 A-A

B-B

B
A
C 1

C 4
É
2
3
B

C-C 7

– 17 –
 CABLE ROUTING SPEC
1 Drive select lever switch B Rear brake light switch
2 Ground terminal C Rear brake light switch lead
3 Throttle cable D Drive select lever switch connector
4 Drive select lever switch lead
5 Main switch lead È Route the rear brake light switch lead over the
6 Headlight lead parking brake cable.
7 Ignition coil É Pass the parking brake cable through the cable
8 Rectifier/regulator guides.
9 Starter motor lead Ê Fasten the drive select lever switch lead with a
0 Starter motor plastic band. Face the end of the plastic band
A Parking brake cable inward.

B B

C 3

Ò D
Ñ
B-B C-C

5 Í
B B
3 4Ì Î
A
Ë2 6
Ê 1 C
7
É 8
È
C

B A 0 9 Ð Ï

– 18 –
 CABLE ROUTING SPEC
Ë Route the drive select lever switch lead on the Ð Pass the starter motor lead through the guide.
outside of the drive select lever bracket, and Ñ Fasten the rear brake light switch lead under the
then under the ground lead. frame with two plastic bands. Face the end of
Ì Fasten the throttle cable and drive select lever each band rearward.
switch lead with a plastic clamp. Ò Pass a plastic band through the holes in the fuel
Í Route the main switch lead over the headlight tank shield, and then fasten the throttle cable
bracket. and drive select lever switch connector with the
Î Pass the headlight lead between the headlight plastic band. The end of the plastic band should
bracket and the headlight. be under the frame, facing inward.
Ï Route the starter motor lead in front of the front
fender bracket.

B B

C 3

Ò D
Ñ
B-B C-C

5 Í
B B
3 4Ì Î
A
Ë2 6
Ê 1 C
7
É 8
È
C

B A 0 9 Ð Ï

– 19 –
 CABLE ROUTING SPEC
1 Ignition coil È Fasten the wire harness with the holder.
2 Headlight lead É Route the headlight lead over the frame.
3 Main switch lead Ê Fasten the main switch lead with the holder on
4 Spark plug lead the front fender.
5 Drive select lever switch lead Ë Pass the main switch lead through the guide on
6 Throttle cable the front fender.
7 Starter motor lead
8 Wire harness
9 Starter cable
0 Rectifier/regulator

È
1

2É

A-A 3Ë
0
A Ê
A
3
È

2É 9

4
5

7 6

– 20 –
 CABLE ROUTING SPEC
1 Starter relay È Fasten the wire harness by inserting the projec-
2 Positive battery lead tions on the plastic tab into the hole in the rear
3 C.D.I. unit fender.
4 Battery É Pass the tail/brake light lead through the guide
5 Tail/brake light lead on the rear fender.
6 Negative battery lead Ê Fasten the tail/brake light lead with the holders
7 Starting circuit cut-off relay on the rear fender.
8 Wire harness Ë Route the tail/brake light lead under the battery
9 Starter motor lead holding bracket.

Í È
9
1

2
8
3
7
6Ì
Ê
5Ë 4
Ê

É
Ê
É

– 21 –
 CABLE ROUTING SPEC
Ì Connect the end of the negative battery lead
with the gray tape to the negative battery termi-
nal.
Í Cover the positive battery lead terminal and
starter motor lead terminal with the covers.

Í È
9
1

2
8
3
7
6Ì
Ê
5Ë 4
Ê

É
Ê
É

– 22 –
 INTRODUCTION/ CHK
PERIODIC MAINTENANCE/LUBRICATION ADJ
EB300000

PERIODIC CHECKS AND ADJUSTMENTS

INTRODUCTION
This chapter includes all information necessary to perform recommended inspections and adjust-
ments. These preventive maintenance procedures, if followed, will ensure more reliable vehicle
operation and a longer service life. The need for costly overhaul work will be greatly reduced. This
information applies to vehicles already in service as well as to new vehicles that are being prepared
for sale. All service technicians should be familiar with this entire chapter.

PERIODIC MAINTENANCE/LUBRICATION
INITIAL EVERY
ITEM ROUTINE 1 3 6 6 1
month months months months year
• Check valve clearance.
Valves*
• Adjust if necessary.
• Check condition.
Spark plug • Adjust gap and clean.
• Replace if necessary.
• Clean. Every 20 ~ 40 hours
Air filter element
• Replace if necessary. (More often in wet or dusty areas.)
• Check starter (choke) operation.
Carburetor*
• Adjust engine idling speed.
Crankcase breather • Check breather hose for cracks or damage.
system* • Replace if necessary.
• Check for leakage.
Exhaust system* • Tighten if necessary.
• Replace gasket(s) if necessary.
• Check fuel hose for cracks or damage.
Fuel line*
• Replace if necessary.
Engine oil • Replace. (Warm engine before draining.)
Engine oil filter ele- • Clean.
ment • Replace if necessary.
Engine oil strainer • Clean.
Drive chain • Check and adjust slack/alignment/clean/lube.
• Check operation/fluid leakage/See NOTE page 24.
Brakes*
• Correct if necessary.
• Check operation.
Clutch*
• Adjust if necessary.
• Check balance/damage/runout.
Wheels*
• Replace if necessary.
• Check bearing assemblies for looseness/damage.
Wheel bearings*
• Replace if damaged.
• Check operation.
• Repair if damaged.
Steering system*
• Check toe-in.
• Adjust if necessary.
Front and rear sus- • Check operation.
pension* • Correct if necessary.
Upper and lower arm
• Lubricate every 6 months with lithium-soap-based
pivot and steering
grease.
shaft*
• Lubricate every 6 months with lithium-soap-based
Rear arm pivot*
grease.

– 23 –
 CHK
PERIODIC MAINTENANCE/LUBRICATION ADJ
INITIAL EVERY
ITEM ROUTINE 1 3 6 6 1
month months months months year
Fittings and fasten- • Check all chassis fittings and fasteners.
ers* • Correct if necessary.
Lights and • Check operation.
switches* • Adjust headlight beams.

* Since these items require special tools, data and technical skills, have a Yamaha dealer perform the ser-
vice.
NOTE:
_

• Recommended brake fluid: DOT 4

• Brake fluid replacement:
• When disassembling the master cylinders or calipers, replace the brake fluid. Normally check
the brake fluid level and add fluid as required.
• On the inner parts of the master cylinders and calipers, replace the oil seals every two years.
• Replace the brake hoses every four years, or if cracked or damaged.

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

– 24 –
 CHK
SEAT, FENDERS AND FUEL TANK ADJ
EBS00033

SEAT, FENDERS AND FUEL TANK

SEAT, SIDE COVERS, AND FRONT PANEL

1
3

Order Job/Part Q’ty Remarks

Removing the seat, side covers, and Remove the parts in the order listed.
front panel
1 Seat 1 NOTE:
_

Pull back the seat lock lever, than pull up

on the rear of the seat.

2 Left side cover 1

3 Right side cover 1
4 Front panel 1
For installation, reverse the removal pro-
cedure.

– 25 –
 CHK
SEAT, FENDERS AND FUEL TANK ADJ
EBS00034

FOOT PROTECTORS, ENGINE SKID PLATE, AND FRONT BUMPER

17 Nm (1.7 m • kg, 12 ft • Ib)

T.
R.
2

17 Nm (1.7 m • kg, 12 ft • Ib)

T.
R.
1
4

12 Nm (1.2 m • kg, 8.7 ft • Ib)

T.
R.

12 Nm (1.2 m • kg, 8.7 ft • Ib)

T.
R.

Order Job/Part Q’ty Remarks

Removing the foot protectors, Remove the parts in the order listed.
engine skid plate, and front bumper
1 Left foot protector 1
2 Right foot protector 1
3 Engine skid plate 1
4 Front bumper 1
For installation, reverse the removal pro-
cedure.

– 26 –
 CHK
SEAT, FENDERS AND FUEL TANK ADJ
EBS00036

HEADLIGHTS AND FRONT FENDER

7 Nm (0.7 m • kg, 5.1 ft • Ib)

T.
R.

5 7 Nm (0.7 m • kg, 5.1 ft • Ib)

T.
R.
4 7 Nm (0.7 m • kg, 5.1 ft • Ib)

T.
R.
3

7 Nm (0.7 m • kg, 5.1 ft • Ib) 2

T.
R.

Order Job/Part Q’ty Remarks

Removing the headlights and front Remove the parts in the order listed.
fender
Seat/side covers (left and right)/front Refer to “SEAT, SIDE COVERS, AND
panel FRONT PANEL”.
1 Headlight coupler 2 Disconnect.
2 Left headlight 1
3 Right headlight 1
4 Main switch coupler 1 Disconnect.
5 Front fender 1
For installation, reverse the removal pro-
cedure.

– 27 –
 CHK
SEAT, FENDERS AND FUEL TANK ADJ
EBS00039

REAR FENDER

3 Nm (0.3 m • kg, 2.2 ft • Ib)

T.
R.

3 Nm (0.3 m • kg, 2.2 ft • Ib)

T.
R.
10 Nm (1.0 m • kg, 7.2 ft • Ib)

T.
R.
2
1
6
9 3

7
8
5
4

11
10

7 Nm (0.7 m • kg, 5.1 ft • Ib)

T.
R.

Order Job/Part Q’ty Remarks

Removing the rear fender Remove the parts in the order listed.
Seat/side covers (left and right) Refer to “SEAT, SIDE COVERS, AND
FRONT PANEL”.
1 Battery lead 2 CAUTION:
_

First disconnect the negative lead,

then disconnect the positive lead.

2 Battery holding bracket 1

3 Battery 1
4 Crankcase breather hose 1 Disconnect.
5 Clamp screw 1 Loosen.
6 Air filter case 1
7 Starter relay 1
8 Starting circuit cut-off relay 1
9 C.D.I. unit 1

– 28 –
 CHK
SEAT, FENDERS AND FUEL TANK ADJ

3 Nm (0.3 m • kg, 2.2 ft • Ib)

T.
R.

3 Nm (0.3 m • kg, 2.2 ft • Ib)

T.
R.
10 Nm (1.0 m • kg, 7.2 ft • Ib)

T.
R.
2
1
6
9 3

7
8
5
4

11
10

7 Nm (0.7 m • kg, 5.1 ft • Ib)

T.
R.

Order Job/Part Q’ty Remarks

10 Tail/brake light coupler 1 Disconnect.
11 Rear fender 1
For installation, reverse the removal pro-
cedure.

– 29 –
 CHK
SEAT, FENDERS AND FUEL TANK ADJ
EBS00042

FUEL TANK

7 Nm (0.7 m • kg, 5.1 ft • Ib)

T.
R.

3
1

Order Job/Part Q’ty Remarks

Removing the fuel tank Remove the parts in the order listed.
Seat/side covers (left and right) Refer to “SEAT, SIDE COVERS, AND
FRONT PANEL”.
Front fender Refer to “HEADLIGHTS AND FRONT
FENDER”.
1 Fuel hose (fuel cock side) 1 NOTE:
_

Before disconnecting the fuel hose, turn

the fuel cock to “OFF”.

2 Fuel tank 1 NOTE:

_

When installing the fuel tank, pass the

fuel tank breather hose through the hole
in the handlebar cover.

3 Plastic band 2

– 30 –
 CHK
SEAT, FENDERS AND FUEL TANK ADJ

7 Nm (0.7 m • kg, 5.1 ft • Ib)

T.
R.

3
1

Order Job/Part Q’ty Remarks

4 Fuel tank shield 1
For installation, reverse the removal pro-
cedure.

– 31 –
CHECKING THE FRONT BRAKE PADS/ CHK
ADJUSTING THE PARKING BRAKE ADJ
CHASSIS
CHECKING THE FRONT BRAKE PADS
1. Remove:
• front wheels
Refer to “FRONT WHEEL AND WHEEL
HUB” in chapter 6. (Manual No.: 3GD-AE5)
2. Check:
• brake pads
Wear indicator 1 almost in contact with the
brake disc → Replace the brake pads as a
set.
Refer to “FRONT BRAKE” in chapter 6.
(Manual No.: 3GD-AE5)

Brake pad wear limit a

1.0 mm (0.04 in)

3. Operate the brake lever.

4. Install:
• front wheels
Refer to “FRONT WHEEL AND WHEEL
HUB” in chapter 6. (Manual No.: 3GD-AE5)

ADJUSTING THE PARKING BRAKE

1. Check:
• parking brake cable end length a
Out of specification → Adjust.

Parking brake cable end length

64 ~ 68 mm (2.52 ~ 2.68 in)

2. Adjust:
• parking brake cable end length
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Loosen the locknut 1 and adjusting bolt 2.
b. Slide back the rubber cover.
c. Loosen the locknut 3.
d. Turn the adjusting nut 4 in direction b or
c until the specified brake cable end length
is obtained.
e. Tighten the locknut 3.
f. Slowly turn the adjusting bolt clockwise until
resistance is felt.
g. Turn it 1/8 counterclockwise.
h. Tighten the locknut 1.

Locknut
16 Nm (1.6 m · kg, 11 ft · lb)
T.
R.

– 32 –
 ADJUSTING THE PARKING BRAKE/ CHK
ADJUSTING THE REAR SHOCK ABSORBER ADJ
i. Slide the rubber cover to its original posi-
tion.
WARNING
After this adjustment is performed, lift the
rear wheels off the ground by placing a
block under the engine, and spin the rear
wheels to ensure there is no brake drag. If
any brake drag is noticed perform the
above steps again.

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

EBS00111
ADJUSTING THE REAR SHOCK
ABSORBER
1. Remove:
• seat
Refer to “SEAT, SIDE COVERS, AND
FRONT PANEL”.
2. Remove:
• air filter case
Refer to “REAR FENDER”.
3. Adjust:
• spring preload
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Elevate the rear wheels by placing a suit-
able stand under the frame.
b. Loosen the locknut 1.
c. Turn the adjusting ring 2 in direction a or
b.

Spring preload is
Direction a increased (suspension
is harder).
Spring preload is
Direction b decreased (suspension
c is softer).

Adjusting length c
Standard: 228.5 mm (9.00 in)
Minimum: 218.5 mm (8.60 in)
Maximum: 233.5 mm (9.19 in)

– 33 –
 CHK
ADJUSTING THE REAR SHOCK ABSORBER ADJ
NOTE:
_

• Be sure to remove all dirt and mud from

around the locknut and adjusting ring before
adjustment.
• The length of the spring (installed) changes
1 mm (0.04 in) per turn of the adjuster.

CAUTION:
_

Never attempt to turn the adjusting ring

beyond the maximum or minimum setting.

d. Tighten the locknut 1 with a steering nut

wrench 3.
NOTE:
Set the torque wrench at a right angle to the
steering nut wrench.

Steering nut wrench

P/N. 90890-01443/YU-33975

Locknut
42 Nm (4.2 m · kg, 30 ft · lb)
T.
R.

NOTE:
_

Always tighten the locknut against the adjust-

ing ring, then torque it to specification.

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
4. Install:
• air filter case
Refer to “REAR FENDER”.
5. Install:
• seat
Refer to “SEAT, SIDE COVERS, AND
FRONT PANEL”.

– 34 –
 CHK
CHECKING AND CHARGING THE BATTERY ADJ
EBS00120

ELECTRICAL SYSTEM
CHECKING AND CHARGING THE
BATTERY
WARNING
_

Batteries generate explosive hydrogen gas

and contain electrolyte which is made of
poisonous and highly caustic sulfuric acid.
Therefore, always follow these preventive
measures:
• Wear protective eye gear when handling
or working near batteries.
• Charge batteries in a well-ventilated area.
• Keep batteries away from fire, sparks or
open flames (e.g., welding equipment,
lighted cigarettes).
• DO NOT SMOKE when charging or han-
dling batteries.
• KEEP BATTERIES AND ELECTROLYTE
OUT OF REACH OF CHILDREN.
• Avoid bodily contact with electrolyte as it
can cause severe burns or permanent eye
injury.
FIRST AID IN CASE OF BODILY CONTACT:
EXTERNAL
• Skin — Wash with water.
• Eyes — Flush with water for 15 minutes
and get immediate medical attention.
INTERNAL
• Drink large quantities of water or milk fol-
lowed with milk of magnesia, beaten egg
or vegetable oil. Get immediate medical
attention.

CAUTION:
_

• This is a sealed battery. Never remove the

sealing caps because the balance
between cells will not be maintained and
battery performance will deteriorate.
• Charging time, charging amperage and
charging voltage for an MF battery are dif-
ferent from those of conventional batter-
ies. The MF battery should be charged as
explained in the charging method illustra-
tions. If the battery is overcharged, the
electrolyte level will drop considerably.
Therefore, take special care when charg-
ing the battery.

– 35 –
 CHK
CHECKING AND CHARGING THE BATTERY ADJ
NOTE:
_

Since MF batteries are sealed, it is not possi-

ble to check the charge state of the battery by
measuring the specific gravity of the electro-
lyte. Therefore, the charge of the battery has to
be checked by measuring the voltage at the
battery terminals.

1. Remove:
• seat
Refer to “SEAT, SIDE COVERS, AND
FRONT PANEL”.
2. Disconnect:
• battery leads
(from the battery terminals)
CAUTION:
_

First, disconnect the negative battery lead

1, and then the positive battery lead 2.

3. Remove:
• battery holding bracket
Refer to “REAR FENDER”.
4. Remove:
• battery
5. Check:
• battery charge
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Connect a pocket tester to the battery termi-
nals.

Relationship between the open-circuit voltage Positive tester probe →

and the charging time at 20 °C (68 °F)
positive battery terminal
Open-circuit voltage (V)

Negative tester probe →

negative battery terminal

NOTE:
_

• The charge state of an MF battery can be

checked by measuring its open-circuit volt-
Charging time (hours)
These values vary with the temperature, the condition of
age (i.e., the voltage when the positive termi-
the battery plates, and the electrolyte level. nal is disconnected).
• No charging is necessary when the open-cir-
cuit voltage equals or exceeds 12.8 V.

b. Check the charge of the battery, as shown

in the charts and the following example.
Example
c. Open-circuit voltage = 12.0 V
d. Charging time = 6.5 hours
e. Charge of the battery = 20 ~ 30%
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

– 36 –
 CHK
CHECKING AND CHARGING THE BATTERY ADJ
Charging Ambient temperature 6. Charge:
20 °C (68 °F)
• battery
Open-circuit voltage (V)

(refer to the appropriate charging method

illustration)
WARNING
_

Do not quick charge a battery.

Time (minutes)
Check the open-circuit
voltage. CAUTION:
_

• Never remove the MF battery sealing

Ambient caps.
Open-circuit voltage (V)

temperature
20 °C (68 °F)
• Do not use a high-rate battery charger
since it forces a high-amperage current
into the battery quickly and can cause
battery overheating and battery plate
damage.
• If it is impossible to regulate the charging
current on the battery charger, be careful
Charging condition of the battery (%)
not to overcharge the battery.
• When charging a battery, be sure to
remove it from the machine. (If charging
has to be done with the battery mounted
on the machine, disconnect the negative
battery lead from the battery terminal.)
• To reduce the chance of sparks, do not
plug in the battery charger until the bat-
tery charger leads are connected to the
battery.
• Before removing the battery charger lead
clips from the battery terminals, be sure
to turn off the battery charger.
• Make sure the battery charger lead clips
are in full contact with the battery termi-
nal and that they are not shorted. A cor-
roded battery charger lead clip may
generate heat in the contact area and a
weak clip spring may cause sparks.
• If the battery becomes hot to the touch at
any time during the charging process,
disconnect the battery charger and let the
battery cool before reconnecting it. Hot
batteries can explode!
• As shown in the following illustration, the
open-circuit voltage of an MF battery sta-
bilizes about 30 minutes after charging
has been completed. Therefore, wait 30
minutes after charging is completed
before measuring the open-circuit volt-
age.

– 37 –
 CHK
CHECKING AND CHARGING THE BATTERY ADJ
Charging method using a variable-current (voltage) charger

NOTE:
Measure the open-circuit Leave the battery unused for
Charger voltage prior to charging. more than 30 minutes before
Ammeter measuring its open-circuit voltage.

Connect a charger and NOTE:

ammeter to the battery and Set the charging voltage to 16 ~
start charging. 17 V. (If the charging voltage is
lower, charging will be insufficient,
if it is higher, the battery will be
over-charged.)
Is the amperage higher
YES than the standard charging NO
amperage written on the
battery?

Adjust the charging voltage to

20 ~ 25 V.

Monitor the amperage for

Adjust the voltage to obtain the YES
3 ~ 5 minutes. Is the standard
standard charging amperage. charging amperage exceeded?

NO

If the amperage does not

Set the timer to the charging exceed the standard charging
time determined by the open- amperage after 5 minutes,
circuit voltage. replace the battery.
Refer to “CHECKING AND
CHARGING THE BATTERY”.

If the required charging time exceeds 5 hours, it is advisable to check the

charging amperage after 5 hours. If there is any change in the amperage,
readjust the voltage to obtain the standard charging amperage.

Leave the battery unused for more than 30 minutes before measuring its
open-circuit voltage.
12.8 V → Charging is complete.
12.0 ~ 12.7 V → Recharging is required.
Under 12.0 V → Replace the battery.

– 38 –
 CHK
CHECKING AND CHARGING THE BATTERY ADJ
Charging method using a constant voltage charger

NOTE:
Measure the open-circuit
Leave the battery unused for
voltage prior to charging. more than 30 minutes before
measuring its open-circuit voltage.

Connect a charger and

ammeter to the battery
and start charging.

Is the amperage higher

YES than the standard charg- NO
ing amperage written on
the battery?

Charge the battery until the charging This type of battery charger cannot
voltage reaches 15 V. charge an MF battery. A variable-volt-
age charger is recommended.
NOTE:
Set the charging time to a maxi-
mum of 20 hours.

Charger

Leave the battery unused for more than Ammeter

30 minutes before measuring its open-cir- Voltmeter
cuit voltage.
12.8 V → Charging is complete.
12.0 ~ 12.7 V → Recharging is required.
Under 12.0 V → Replace the battery.

CAUTION:
Constant amperage chargers are not
suitable for charging MF batteries.

– 39 –
CHECKING AND CHARGING THE BATTERY/ CHK
ADJUSTING THE HEADLIGHT BEAMS ADJ
7. Install:
• battery
8. Install:
• battery holding bracket
Refer to “REAR FENDER”.
9. Connect:
• battery leads
(to the battery terminals)
CAUTION:
_

First, connect the positive battery lead 1,

and then the negative battery lead 2.

10.Check:
• battery terminals
Dirt → Clean with a wire brush.
Loose connection → Connect properly.
11.Lubricate:
• battery terminals

Recommended lubricant
Dielectric grease

12.Install:
• seat
Refer to “SEAT, SIDE COVERS, AND
FRONT PANEL”.

EBS00122
ADJUSTING THE HEADLIGHT BEAMS
1. Adjust:
• headlight beam (vertically)
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Turn the adjusting bolt 1 in direction a or
b.

Headlight beam is
Direction a
raised.
Headlight beam is
Direction b
lowered.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

– 40 –
 CHK
REPLACING A HEADLIGHT BULB ADJ
EBS00124
REPLACING A HEADLIGHT BULB
1. Disconnect:
• headlight lead coupler 1
2. Remove:
• headlight bulb holder cover 2

3. Remove:
• bulb holder 1
• bulb
NOTE:
_

Push the headlight bulb holder inward, turn it

counterclockwise and remove the defective
bulb.

WARNING
_

Keep flammable products and your hands

away from the bulb while it is on, since it
will be hot. Do not touch the bulb until it
cools down.

4. Install:
• bulb New
CAUTION:
_

Avoid touching the glass part of the bulb.

Keep it free from oil; otherwise, the trans-
parency of the glass, life of the bulb, and
luminous flux will be adversely affected. If
oil gets on the bulb, thoroughly clean it
with a cloth moistened with alcohol or lac-
quer thinner.

5. Install:
• bulb holder
• headlight bulb holder cover 1
NOTE:
After installing the bulb holder cover, make
sure that the “TOP” mark a is in the position
shown.

6. Connect:
• headlight lead coupler 2

– 41 –
 ENGINE REMOVAL ENG
ENGINE
ENGINE REMOVAL
5
5 INSTALLING THE ENGINE
6 WARNING
5
Securely support the machine so there is
no danger of it falling over.
4
6 1. Install:
• engine assembly
2 2. Install:
• engine lower mounting bolt (rear)/nut 1
• engine upper mounting bolt (rear)/nut 2
• engine lower mounting bolt (front)/nut 3
• engine bracket (left and right) 4
3
• engine bracket bolts 5
1 • engine upper mounting bolt (front)/nut 6
NOTE:
• All mounting bolts should be installed from
the right of the machine.
• Do not fully tighten the bolts and nuts.

3. Tighten:
• engine lower mounting bolt (rear)/nut 1
73 Nm (7.3 m · kg, 53 ft · lb)
T.
R.

• engine upper mounting bolt (rear)/nut 2

73 Nm (7.3 m · kg, 53 ft · lb)
T.
R.

• engine lower mounting bolt (front)/nut 3

73 Nm (7.3 m · kg, 53 ft · lb)
T.
R.

• engine bracket bolts 5

33 Nm (3.3 m · kg, 24 ft · lb)
T.
R.

• engine upper mounting bolt (front)/nut 6

33 Nm (3.3 m · kg, 24 ft · lb)
T.
R.

– 42 –
 CLUTCH ENG
CLUTCH
INSTALLING THE RIGHT CRANKCASE
COVER
b 1. Install:
a c • right crankcase cover
10 Nm (1.0 m · kg, 7.2 ft · lb)

T.
R.
NOTE:
When installing the right crankcase cover,
push the push lever in direction a and check
that the punch mark b on the push lever
aligns with the mark c on the right crankcase
cover.

– 43 –
 CARBURETOR CARB
EBS00141

CARBURETOR
CARBURETOR

3
New
8
4

6
20 Nm (2.0 m • kg, 14 ft • Ib)

T.
R.
5 1

Order Job/Part Q’ty Remarks

Removing the carburetor Remove the parts in the order listed.
Fuel tank/air filter case Refer to “SEAT, FENDERS AND FUEL
TANK”.
1 Plastic band 1
2 Drive select lever assembly 1
3 Throttle valve cover 1
4 Throttle cable 1
5 Carburetor air vent hose 1 Disconnect.
6 Starter plunger 1
7 Clamp screw 1 Loosen.
8 Carburetor 1
For installation, reverse the removal pro-
cedure.

– 44 –
 CARBURETOR CARB

2
5

G
3

6
4
A
0
C
9 F B
8 E
H

7
1

Order Job/Part Q’ty Remarks

Disassembling the carburetor Remove the parts in the order below.
1 Throttle stop screw 1
2 Vacuum chamber cover 1
3 Piston valve spring 1
4 Jet needle holder/jet needle set 1
5 Piston valve 1
6 Coasting enricher assembly 1
7 Float chamber 1
8 Float pin 1
9 Float 1
0 Needle valve 1
A Needle valve seat 1
B Starter jet 1
C Pilot jet 1
D Main jet 1

– 45 –
 CARBURETOR CARB

2
5

G
3

6
4
A
0
C
9 F B
8 E
H

7
1

Order Job/Part Q’ty Remarks

E Main jet holder 1
F Needle jet 1
G Pilot air jet 1
H Pilot screw 1
For assembly, reverse the disassembly
procedure.

– 46 –
 REAR WHEELS AND REAR AXLE HUB CHAS
CHASSIS
REAR WHEELS AND REAR AXLE HUB

(4) 3
1 New 120 Nm (12.0 m • kg, 85 ft • lb)

T.
R.
28 Nm (2.8 m • kg, 20 ft • Ib) 2 7 Nm (0.7 m • kg, 5.1 ft • Ib)
T.
R.

T.
R.
4
LT
5
160 Nm (16.0 m • kg, 115 ft • lb)
6

T.
R.
LT
LT
5
11
10 LS
(4) LT

9 34 Nm (3.4 m • kg, 24 ft • Ib)

T.
R.
14 120 Nm (12.0 m • kg, 85 ft • lb)
8

T.
R.
7
LS

16 Nm (1.6 m • kg, 11 ft • Ib) 13

T.
R.

8
7
4 12
14
(4)
2 3

New 1 (4)
73 Nm (7.3 m • kg, 53 ft • lb)
T.
R.

120 Nm (12.0 m kg, 85 ft lb)

• •
T.

55 Nm (5.5 m • kg, 40 ft • Ib)

R.

45 Nm (4.5 m • kg, 32 ft • Ib)

T.
R.
T.
R.

Order Job/Part Q’ty Remarks

Removing the rear wheels and rear Remove the parts in the order listed.
axle hub
1 Cotter pin 2 Refer to “REAR WHEEL AND WHEEL
2 Axle nut 2 HUB” in chapter 6.
3 Rear wheel 2 (Manual No.: 3GD-AE5)
4 Wheel hub 2
5 Bolt 2
Refer to “REMOVING THE REAR
6 Nut 1
AXLE” and “INSTALLING THE REAR
7 Locknut 2
AXLE”.
8 Adjusting bolt 2
9 Brake caliper 1 NOTE:
Do not apply the brake pedal and do not
use the parking brake when the brake
caliper is off of the brake disc as the
brake pad will be force shut.

– 47 –
 REAR WHEELS AND REAR AXLE HUB CHAS

(4) 3
1 New 120 Nm (12.0 m • kg, 85 ft • lb)

T.
R.
28 Nm (2.8 m • kg, 20 ft • Ib) 2 7 Nm (0.7 m • kg, 5.1 ft • Ib)
T.
R.

T.
R.
4
LT
5
160 Nm (16.0 m • kg, 115 ft • lb)
6

T.
R.
LT
LT
5
11
10 LS
(4) LT

9 34 Nm (3.4 m • kg, 24 ft • Ib)

T.
R.
14 120 Nm (12.0 m • kg, 85 ft • lb)
8

T.
R.
7
LS

16 Nm (1.6 m • kg, 11 ft • Ib) 13

T.
R.

8
7
4 12
14
(4)
2 3

New 1 (4)
73 Nm (7.3 m • kg, 53 ft • lb)
T.
R.

120 Nm (12.0 m • kg, 85 ft • lb)

T.

55 Nm (5.5 m • kg, 40 ft • Ib)

R.

45 Nm (4.5 m • kg, 32 ft • Ib)

T.
R.
T.
R.

Order Job/Part Q’ty Remarks

10 Brake disc/brake disc bracket 1/1
11 Rear axle 1 Refer to “REMOVING THE REAR AXLE”.
12 Driven sprocket/sprocket bracket 1/1
13 Rear axle hub 1
14 Spacer/bearing/oil seal 1/2/2
For installation, reverse the removal pro-
cedure.

– 48 –
 REAR WHEELS AND REAR AXLE HUB CHAS
EBS00393

1 REMOVING THE REAR AXLE

1. Place the machine on a level surface.
2. Remove:
• bolts 1
1 3. Loosen:
• nut 2
NOTE:
_

2 • Apply the parking brake so that the rear axle

does not turn, when loosening the nut.
• Use the axle nut wrench (46 mm) 3.

Axle nut wrench (46 mm)

P/N. 90890-01498/YM-37134

4. Elevate the rear wheels by placing the suit-

able stand under the frame.
5. Remove:
• rear wheels
• wheel hubs
• nut

6. Loosen:
• rear axle hub nuts 1

7. Loosen:
• locknut 1
• adjusting bolt 2
NOTE:
Loosen the locknut and adjusting bolt on each
side of the machine.

– 49 –
REAR WHEELS AND REAR AXLE HUB CHAS
8. Remove:
• rear axle 1
CAUTION:
_

• Never directly tap the axle end with a

hammer, since this will result in damage
to the axle thread and spline.
• Attach a suitable socket 2 on the axle
end and tap it with a soft hammer, then
pull out the rear axle to the right.

EBS00397
INSTALLING THE REAR AXLE
1. Install:
• nut 1
• bolts 2
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Tighten the nut with rear axle nut wrench
(46 mm) 3 to specification while holding
the rear axle.

Axle nut wrench (46 mm)

P/N. 90890-01498/YM-37134
2 1
Nut
160 Nm (16.0 m · kg, 115 ft · lb)
T.

LOCTITE®
R.

b. Tighten bolts 2.

2 Bolt
7 Nm (0.7 m · kg, 5.1 ft · lb)
T.

LOCTITE®
R.

▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲

– 50 –
 FRONT ARMS AND FRONT SHOCK ABSORBER CHAS
EBS00468

FRONT ARMS AND FRONT SHOCK ABSORBER

45 Nm (4.5 m • kg, 32 ft • Ib)

T.
R.
T.
R.
48 Nm (4.8 m • kg, 35 ft • Ib)
25 Nm (2.5 m • kg, 18 ft • Ib)

T.
R.
7 Nm (0.7 m • kg, 5.1 ft • Ib)

T.
R.
LS LS

8
6
6
8
6 7
8 3

LS 7 New
8
LS
6
New 1
25 Nm (2.5 m • kg, 18 ft • Ib)
T.
R.

5 6
LS 78
45 Nm (4.5 m • kg, 32 ft • Ib)
T.
R.

LS 6 LS

2
LS
8 6
8
4
7
6
LS

48 Nm (4.8 m • kg, 35 ft • Ib)

T.
R.

Order Job/Part Q’ty Remarks

Removing the front arms and front Remove the parts in the order listed.
shock absorber The following procedure applies to both
of the front arms and front shock absorb-
ers.
Muffler/exhaust pipe Refer to “ENGINE ASSEMBLY AND
ADJUSTMENT” in chapter 4.
(Manual No.: 3GD-AE5)
Front wheel/brake disc/front brake cali- Refer to “FRONT WHEEL AND WHEEL
per HUB” in chapter 6.
(Manual No.: 3GD-AE5)
Front bumper Refer to “SEAT, FENDERS AND FUEL
TANK”.
1 Tie-rod 1 Disconnect.
2 Front shock absorber 1

– 51 –
 FRONT ARMS AND FRONT SHOCK ABSORBER CHAS

45 Nm (4.5 m • kg, 32 ft • Ib)

T.
R.
T.
R.
48 Nm (4.8 m • kg, 35 ft • Ib)
25 Nm (2.5 m • kg, 18 ft • Ib)

T.
R.
7 Nm (0.7 m • kg, 5.1 ft • Ib)

T.
R.
LS LS

8
6
6
8
6 7
8 3

LS 7 New
8
LS
6
New 1
25 Nm (2.5 m • kg, 18 ft • Ib)
T.
R.

5 6
LS 78
45 Nm (4.5 m • kg, 32 ft • Ib)
T.
R.

LS 6 LS

2
LS
8 6
8
4
7
6
LS

48 Nm (4.8 m • kg, 35 ft • Ib)

T.
R.

Order Job/Part Q’ty Remarks

3 Upper front arm 1 Refer to “FRONT SUSPENSION—
4 Lower front arm 1 REMOVAL” in chapter 6.
(Manual No.: 3GD-AE5)
5 Steering knuckle 1
6 Dust cover 8
7 Spacer 4
8 Bushing 8
For installation, reverse the removal pro-
cedure.

– 52 –
 REAR BRAKE CHAS
REAR BRAKE
a
ASSEMBLING THE REAR BRAKE CALIPER
1. Install:
• parking brake arm 1
1 NOTE:
Install the parking brake arm so that the park-
ing-brake-arm-to-parking-brake-bracket dis-
tance a is approximately 73 mm (2.87 in).

– 53 –
 REAR SHOCK ABSORBER AND SWINGARM CHAS
REAR SHOCK ABSORBER AND SWINGARM

73 Nm (7.3 m • kg, 53 ft • lb)

10

T.
R.
LS
LS
LS
12
14

3
11 14 9
LS
3
10 LS

14
6
4 13
2 6 12

80 Nm (8.0 m • kg, 58 ft • Ib)

T.
R.

5
LS LS
LS

8 LS

8
8
7 LS
8
85 Nm (8.5 m • kg, 61 ft • Ib) 73 Nm (7.3 m • kg, 53 ft • lb)
1
T.

T.
R.

R.

Order Job/Part Q’ty Remarks

Removing the rear shock absorber Remove the parts in the order listed.
and swingarm
Rear wheel/rear axle hub Refer to “REAR WHEELS AND REAR
AXLE HUB”.
Parking brake cable/rear brake hose Refer to “REAR SHOCK ABSORBER
AND SWINGARM” in chapter 6.
(Manual No.: 3GD-AE5)
Drive chain Refer to “DRIVE CHAIN AND SPROCK-
ETS” in chapter 6.
(Manual No.: 3GD-AE5)
1 Swingarm skid plate 1
2 Rear shock absorber 1
3 Spacer 2
4 Spacer 1
5 Relay arm 1
6 Dust cover/bushing/spacer 2/2/1

– 54 –
 REAR SHOCK ABSORBER AND SWINGARM CHAS

73 Nm (7.3 m • kg, 53 ft • lb)

10

T.
R.
LS
LS
LS
12
14

3
11 14 9
LS
3
10 LS

14
6
4 13
2 6 12

80 Nm (8.0 m • kg, 58 ft • Ib)

T.
R.

5
LS LS
LS

8 LS

8
8
7 LS
8
85 Nm (8.5 m • kg, 61 ft • Ib) 73 Nm (7.3 m • kg, 53 ft • lb)
1
T.

T.
R.

R.

Order Job/Part Q’ty Remarks

7 Connecting rod 1
8 Oil seal/bushing/spacer 4/4/2
9 Drive chain guide 1
10 Pivot shaft/washer/nut 1/1/1
11 Swingarm 1
12 Dust cover/washer/oil seal 2/2/2
13 Drive chain protector 1
14 Bearing/spacer 2/1
For installation, reverse the removal pro-
cedure.

– 55 –
REAR SHOCK ABSORBER AND SWINGARM CHAS
EBS00485
HANDLING THE REAR SHOCK ABSORBER
AND GAS CYLINDER
WARNING
_

This rear shock absorber and gas cylinder

contain highly compressed nitrogen gas.
Before handling the rear shock absorber or
gas cylinder, read and make sure you
understand the following information. The
manufacturer cannot be held responsible
for property damage or personal injury that
may result from improper handling of the
rear shock absorber and gas cylinder.
• Do not tamper or attempt to open the rear
shock absorber or gas cylinder.
• Do not subject the rear shock absorber or
gas cylinder to an open flame or any
other source of high heat. High heat can
cause an explosion due to excessive gas
pressure.
• Do not deform or damage the rear shock
absorber or gas cylinder in any way. If the
rear shock absorber, gas cylinder or both
are damaged, damping performance will
suffer.

DISPOSING OF THE REAR SHOCK

ABSORBER AND GAS CYLINDER
Gas pressure must be released before dispos-
ing of the rear shock absorber and gas cylinder.
To release the gas pressure, drill a 2 ~ 3-mm
hole through the gas cylinder at a point a
50 mm (1.97 in) from its end as shown.
WARNING
a _

Wear eye protection to prevent eye damage

from released gas or metal chips.

– 56 –
 – +
ELECTRICAL COMPONENTS ELEC
ELECTRICAL
ELECTRICAL COMPONENTS
1 Rectifier/regulator 9 Starting circuit cut-off relay
2 Main switch 0 Fuse
3 Neutral indicator light A Starter relay
4 Reverse indicator light B Reverse switch
5 Ignition coil C Neutral switch
6 Drive select lever switch D Rear brake light switch
7 Battery E Wire harness
8 C.D.I. unit

2 6

7
1
8

D
0

B
A
9
C

– 57 –
 YAMAHA MOTOR CO., LTD.
2500 SHINGAI IWATA SHIZUOKA JAPAN
YFM350S WIRING DIAGRAM
1 A.C. magneto
2 Rectifier/regulator
R
R/B L/W O B G/W
W/R
1 W/G
R W/R W/G W/B B/Y
3 Main switch
W/G
4 Battery
W R W/G W/G R R O O 0 5 Fuse
W W W/L W/R W/R W/G W/R
A 6 Starter relay
W/G
L/W
B
7 Starter motor
W
W W W
8 Clutch switch
W W
R 9 C.D.I. unit
R R R R
R/B
W/B
9 0 Ignition coil
W W W
3 G/W A Spark plug
B Starting circuit cut-off relay
R R
ON
OFF
R Br Br R
4 R R B/Y C Drive select lever switch
B 5 L/W L/B
D Neutral switch
2 Br B E Indicator light assembly
L/W
B/Y F Neutral indicator light
6 B
G Reverse indicator light
L/B H Reverse switch
B B
B R
B R B
8 I Rear brake light switch
W W W
B
B B B/Y B J Front brake light switch
(BLACK) K Tail/brake light
7 B L Headlight
M Handlebar switch
N Light switch
G/W Sb O Engine stop switch
M Br Br R/B L/B
Br W/B P Start switch
Br Br E Br Br W/B Br
(GREEN)

N O P
Br Y
L/B G
L
B
L Y Br B
B G L/B
OFF
J I Br W/B Br W/B F G
B B B B
R/B R/W Br R/B Br G/L Br G/L
(BLACK) (BLACK)
(BLACK) (BLACK) Y Y W/B G/L Sb G/W

L Y G B
Y Br Y Br

(BLACK) (BLACK) Sb G/W

G Y G Y Y L

LL G/L
D C
G Y Y G Y G G Y

B B B B L Y Y L
K
B B
(BLACK) (BLACK) (BLACK) (BLACK)
H
B B B

COLOR CODE
B ............Black Sb ..........Sky blue L/B .........Blue/Black W/L ....... White/Blue
Br ...........Brown W ...........White L/W ........Blue/White W/R ....... White/Red
G............Green Y ............Yellow R/B.........Red/Black
L.............Blue B/Y.........Black/Yellow R/W........Red/White
O............Orange G/L.........Green/Blue W/B ........White/Black
R ............Red G/W .......Green/White W/G........White/Green