4D3 28197 10 2008 Yamaha Raptor 250 Sevice Manual

User Manual: 2008 Yamaha Raptor 250 Sevice Manual

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2008
SERVICE MANUAL

YFM250RX

LIT-11616-21-22

4D3-28197-10

EBS00001

YFM250RX
SERVICE MANUAL
© 2007 by Yamaha Motor
Corporation, U.S.A.
First Edition, July 2007
All rights reserved.
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Corporation, U.S.A.
is expressly prohibited.
Printed in U.S.A
LIT-11616-21-22

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 significant 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

CAUTION:
NOTE:

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.
A CAUTION indicates special precautions that must be taken to avoid damage to the machine.
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 : This is the title of the chapter with its symbol in the upper right corner of each page.
2nd title : 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 : This title indicates a sub-section that is followed by step-by-step procedures accompanied 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
is provided for removal and disassembly jobs.
2. Numbers
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
. The meanings of the symbol marks are given on the next page.
4. A job instruction chart
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
are given in addition
to the exploded diagram and the job instruction chart.

EBS00006

SYMBOLS
The following symbols are not relevant to every
machine.
Symbols
to
indicate the subject of each
chapter.

GEN
INFO

CHAS

General information
Specifications
Periodic checks and adjustments
Engine
Carburetor
Chassis
Electrical
Troubleshooting

Symbols

to

indicate the following

Serviceable with engine mounted
Filling fluid
Lubricant
Special tool
Torque
Wear limit, clearance
Engine speed
Electrical data (Ω, V, A)

Symbols
to
in the exploded diagrams
indicate the types of lubricants and lubrication
points.
Apply engine oil
Apply gear oil
Apply molybdenum disulfide oil
Apply brake fluid
Apply wheel bearing grease
Apply lithium-soap-based grease
Apply molybdenum disulfide grease
Apply silicone grease

Symbols
to
in the exploded diagrams
indicate where to apply a locking agent
and
when to install a new part .
Apply the locking agent (LOCTITE®)
Replace

EBS00008

TABLE OF CONTENTS
GENERAL INFORMATION
SPECIFICATIONS
PERIODIC CHECKS AND
ADJUSTMENTS
ENGINE
CARBURETOR
CHASSIS
ELECTRICAL
TROUBLESHOOTING

GEN
INFO

1

SPEC

2

CHK
ADJ

3

ENG

4

CARB

5

CHAS

6

ELEC

7

TRBL
SHTG

8

CHAPTER 1
GENERAL INFORMATION
MACHINE IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
VEHICLE IDENTIFICATION NUMBER. . . . . . . . . . . . . . . . . . . . . . . . 1-1
MODEL LABEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
IMPORTANT INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
PREPARATION FOR REMOVAL AND DISASSEMBLY . . . . . . . . . . 1-2
REPLACEMENT PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
GASKETS, OIL SEALS AND O-RINGS . . . . . . . . . . . . . . . . . . . . . . . 1-2
LOCK WASHERS/PLATES AND COTTER PINS . . . . . . . . . . . . . . . 1-2
BEARINGS AND OIL SEALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
CIRCLIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
CHECKING THE CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
SPECIAL TOOLS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
ENGINE SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
CHASSIS SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
ELECTRICAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
TIGHTENING TORQUES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
ENGINE TIGHTENING TORQUES . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
CHASSIS TIGHTENING TORQUES . . . . . . . . . . . . . . . . . . . . . . . . . 2-17
HOW TO USE THE CONVERSION TABLE . . . . . . . . . . . . . . . . . . . . . . 2-19
GENERAL TIGHTENING TORQUE SPECIFICATIONS . . . . . . . . . . . . . 2-19
LUBRICATION POINTS AND LUBRICANT TYPES . . . . . . . . . . . . . . . . 2-20
ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
OIL FLOW DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
CABLE ROUTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

CHAPTER 3
PERIODIC CHECKS AND ADJUSTMENTS
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
PERIODIC MAINTENANCE CHART FOR THE EMISSION CONTROL
SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
GENERAL MAINTENANCE AND LUBRICATION CHART . . . . . . . . . . 3-2
SEAT, FENDERS AND FUEL TANK. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
SEAT, FRONT FENDER AND HEADLIGHTS . . . . . . . . . . . . . . . . . . 3-4
FOOT PROTECTORS AND ENGINE SKID PLATE . . . . . . . . . . . . . . 3-5
REAR FENDER AND AIR FILLTER CASE. . . . . . . . . . . . . . . . . . . . . 3-6
FUEL TANK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
ADJUSTING THE VALVE CLEARANCE . . . . . . . . . . . . . . . . . . . . . . 3-9
ADJUSTING THE ENGINE IDLING SPEED. . . . . . . . . . . . . . . . . . . . 3-11
ADJUSTING THE THROTTLE LEVER FREE PLAY . . . . . . . . . . . . . 3-12
ADJUSTING THE SPEED LIMITER . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
CHECKING THE SPARK PLUG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
CHECKING THE IGNITION TIMING . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
MEASURING THE COMPRESSION PRESSURE . . . . . . . . . . . . . . . 3-17
CHECKING THE ENGINE OIL LEVEL . . . . . . . . . . . . . . . . . . . . . . . . 3-19
CHANGING THE ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
ADJUSTING THE CLUTCH CABLE . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
CLEANING THE AIR FILTER ELEMENT . . . . . . . . . . . . . . . . . . . . . . 3-23
CLEANING THE SPARK ARRESTER . . . . . . . . . . . . . . . . . . . . . . . . 3-25
CHASSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
ADJUSTING THE FRONT BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
ADJUSTING THE BRAKE LEVER (For adjustment type model) . . . . 3-26
ADJUSTING THE REAR BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
ADJUSTING THE PARKING BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
CHECKING THE BRAKE FLUID LEVEL . . . . . . . . . . . . . . . . . . . . . . 3-28
CHECKING THE FRONT BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . 3-29
CHECKING THE REAR BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . . 3-30
ADJUSTING THE REAR BRAKE LIGHT SWITCH. . . . . . . . . . . . . . . 3-31
CHECKING THE BRAKE HOSES . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31
BLEEDING THE HYDRAULIC BRAKE SYSTEM . . . . . . . . . . . . . . . . 3-32
ADJUSTING THE SHIFT PEDAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
ADJUSTING THE DRIVE CHAIN SLACK. . . . . . . . . . . . . . . . . . . . . . 3-35
CHECKING THE STEERING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . 3-36
ADJUSTING THE TOE-IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37
CHECKING THE FRONT AND REAR SHOCK ABSORBERS . . . . . . 3-38
ADJUSTING THE FRONT SHOCK ABSORBERS . . . . . . . . . . . . . . . 3-39
ADJUSTING THE REAR SHOCK ABSORBER . . . . . . . . . . . . . . . . . 3-40
CHECKING THE TIRES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41
CHECKING THE WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43

CHECKING AND LUBRICATING THE CABLES . . . . . . . . . . . . . . . . 3-43
LUBRICATING THE LEVERS AND PEDALS . . . . . . . . . . . . . . . . . . . 3-44
ELECTRICAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45
CHECKING AND CHARGING THE BATTERY . . . . . . . . . . . . . . . . . 3-45
CHECKING THE FUSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52
ADJUSTING THE HEADLIGHT BEAM . . . . . . . . . . . . . . . . . . . . . . . . 3-53
REPLACING A HEADLIGHT BULB . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54

CHAPTER 4
ENGINE
ENGINE REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
MUFFLER AND EXHAUST PIPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
INSTALLING THE EXHAUST PIPE AND MUFFLER . . . . . . . . . . . . . 4-2
LEADS, CABLES AND HOSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
ENGINE MOUNTING BOLTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
INSTALLING THE ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
REMOVING THE CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
CHECKING THE CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
CHECKING THE TIMING CHAIN GUIDES . . . . . . . . . . . . . . . . . . . . 4-11
CHECKING THE TIMING CHAIN TENSIONERS . . . . . . . . . . . . . . . . 4-11
INSTALLING THE CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
ROCKER ARM, CAMSHAFT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
REMOVING THE ROCKER ARMS AND CAMSHAFT . . . . . . . . . . . . 4-16
CHECKING THE CAMSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
CHECKING THE ROCKER ARMS AND ROCKER ARM
SHAFTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
INSTALLING THE CAMSHAFT AND ROCKER ARMS . . . . . . . . . . . 4-19
VALVES AND VALVE SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
REMOVING THE VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
CHECKING THE VALVES AND VALVE GUIDES . . . . . . . . . . . . . . . 4-23
CHECKING THE VALVE SEATS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25
CHECKING THE VALVE SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28
INSTALLING THE VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29
CYLINDER AND PISTON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31
REMOVING THE PISTON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-32
CHECKING THE CYLINDER AND PISTON . . . . . . . . . . . . . . . . . . . . 4-32
CHECKING THE PISTON RINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34
CHECKING THE PISTON PIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36
INSTALLING THE PISTON AND CYLINDER . . . . . . . . . . . . . . . . . . . 4-37
CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39
REMOVING THE CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-43
CHECKING THE FRICTION PLATES . . . . . . . . . . . . . . . . . . . . . . . . 4-44

CHECKING THE CLUTCH PLATES . . . . . . . . . . . . . . . . . . . . . . . . . 4-44
CHECKING THE CLUTCH SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . 4-45
CHECKING THE CLUTCH HOUSING . . . . . . . . . . . . . . . . . . . . . . . . 4-45
CHECKING THE CLUTCH BOSS . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45
CHECKING THE PRESSURE PLATE . . . . . . . . . . . . . . . . . . . . . . . . 4-45
CHECKING THE CLUTCH PUSH RODS . . . . . . . . . . . . . . . . . . . . . . 4-46
CHECKING THE PRIMARY DRIVE GEAR . . . . . . . . . . . . . . . . . . . . 4-46
INSTALLING THE CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46
OIL PUMP AND BLANCER WEIGHT GEAR . . . . . . . . . . . . . . . . . . . . . 4-50
REMOVING THE BALANCER WEIGHT GEAR AND OIL PUMP. . . . 4-53
CHECKING THE OIL PUMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53
CHECKING THE BALANCER WEIGHT GEAR . . . . . . . . . . . . . . . . . 4-54
ASSENBLING THE BALANCER DRIVE GEAR . . . . . . . . . . . . . . . . . 4-55
INSTALLING THE OIL PUMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-55
INSTALLING THE BALANCER WEIGHT GEAR . . . . . . . . . . . . . . . . 4-56
SHIFT SHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-57
CHECKING THE SHIFT SHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58
CHECKING THE STOPPER LEVER . . . . . . . . . . . . . . . . . . . . . . . . . 4-58
INSTALLING THE SHIFT SHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58
PICKUP COIL ROTOR AND STARTER CLUTCH . . . . . . . . . . . . . . . . . 4-60
REMOVING THE PICKUPCOIL ROTOR . . . . . . . . . . . . . . . . . . . . . . 4-62
CHECKING THE STARTER CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . 4-63
INSTALLING THE PICKUP COIL ROTOR . . . . . . . . . . . . . . . . . . . . . 4-64
CRANKCASE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-66
DISASSEMBLING THE CRANKCASE . . . . . . . . . . . . . . . . . . . . . . . . 4-69
CHECKING THE CRANKCASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-70
ASSEMBLING THE CRANKCASE . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-70
CRANKSHAFT ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-72
REMOVING THE CRANKSHAFT ASSEMBLY. . . . . . . . . . . . . . . . . . 4-73
REMOVING THE PLUNGER SEAL . . . . . . . . . . . . . . . . . . . . . . . . . . 4-73
CHECKING THE CRANKSHAFT AND CONNECTING ROD . . . . . . . 4-73
CHECKING THE TIMING CHAIN, CRANKSHAFT SPROCKET
AND TIMING CHAIN GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-74
INSTALLING THE PLUNGER SEAL . . . . . . . . . . . . . . . . . . . . . . . . . 4-75
INSTALLING THE CRANKSHAFT ASSEMBLY . . . . . . . . . . . . . . . . . 4-75
TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-77
REMOVING THE TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . 4-80
CHECKING THE SHIFT FORKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-80
CHECKING THE SHIFT DRUM ASSEMBLY . . . . . . . . . . . . . . . . . . . 4-81
CHECKING THE TRANSMISSION. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-81
INSTALLING THE SHIFT FORKS AND SHIFT DRUM
ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-82

CHAPTER 5
CARBURETOR
CARBURETOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
CHECKING THE CARBURETOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
ASSEMBLING THE CARBURETOR . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
INSTALLING THE CARBURETOR JOINT . . . . . . . . . . . . . . . . . . . . . 5-7
INSTALLING THE CARBURETOR . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

CHAPTER 6
CHASSIS
FRONT AND REAR WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
FRONT WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
REAR WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
CHECKING THE WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
CHECKING THE WHEEL HUBS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
CHECKING THE BRAKE DISCS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
INSTALLING THE FRONT WHEEL HUB BEARINGS . . . . . . . . . . . . 6-6
INSTALLING THE FRONT BRAKE DISCS . . . . . . . . . . . . . . . . . . . . 6-6
INSTALLING THE FRONT WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
INSTALLING THE WHEEL HUBS . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
REAR AXLE AND REAR AXLE HUB . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
REMOVING THE REAR AXLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
CHECKING THE REAR AXLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
CHECKING THE DRIVEN SPROCKET . . . . . . . . . . . . . . . . . . . . . . . 6-11
CHECKING THE BRAKE DISC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
INSTALLING THE DRIVEN SPROCKET . . . . . . . . . . . . . . . . . . . . . . 6-11
INSTALLING THE REAR AXLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
FRONT AND REAR BRAKES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
FRONT BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
REAR BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
REPLACING THE FRONT BRAKE PADS . . . . . . . . . . . . . . . . . . . . . 6-15
REPLACING THE REAR BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . 6-17
FRONT BRAKE MASTER CYLINDER . . . . . . . . . . . . . . . . . . . . . . . . 6-19
REAR BRAKE MASTER CYLINDER . . . . . . . . . . . . . . . . . . . . . . . . . 6-21
CHECKING THE MASTER CYLINDERS . . . . . . . . . . . . . . . . . . . . . . 6-24
ASSEMBLING THE FRONT BRAKE MASTER CYLINDER . . . . . . . 6-25
ASSEMBLING THE REAR BRAKE MASTER CYLINDER . . . . . . . . 6-25
INSTALLING THE FRONT BRAKE MASTER CYLINDER . . . . . . . . . 6-26
INSTALLING THE REAR BRAKE MASTER CYLINDER . . . . . . . . . . 6-28
FRONT BRAKE CALIPERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30
REAR BRAKE CALIPER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-32
REMOVING THE PARKING BRAKE CABLE . . . . . . . . . . . . . . . . . . . 6-34
DISASSEMBLING THE FRONT AND REAR BRAKE CALIPERS . . . 6-34
CHECKING THE FRONT AND REAR BRAKE CALIPERS . . . . . . . . 6-35
ASSEMBLING THE FRONT BRAKE CALIPERS . . . . . . . . . . . . . . . . 6-36

ASSEMBLING THE REAR BRAKE CALIPER . . . . . . . . . . . . . . . . . . 6-36
INSTALLING THE FRONT BRAKE CALIPERS . . . . . . . . . . . . . . . . . 6-38
INSTALLING THE REAR BRAKE CALIPER . . . . . . . . . . . . . . . . . . . 6-40
STEERING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-42
HANDLEBAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-42
REMOVING THE CLUTCH SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . 6-44
REMOVING THE HANDLEBAR GRIPS . . . . . . . . . . . . . . . . . . . . . . 6-44
CHECKING THE HANDLEBAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44
INSTALLING THE HANDLEBAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-45
INSTALLING THE HANDLEBAR GRIPS . . . . . . . . . . . . . . . . . . . . . . 6-45
INSTALLING THE CLUTCH LEVER. . . . . . . . . . . . . . . . . . . . . . . . . . 6-46
INSTALLING THE BRAKE MASTER CYLINDER . . . . . . . . . . . . . . . 6-46
STEERING STEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-47
CHECKING THE STEERING STEM. . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
INSTALLING THE STEERING STEM. . . . . . . . . . . . . . . . . . . . . . . . . 6-48
INSTALLING THE LOCK WASHER . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
TIE-RODS AND STEERING KNUCKLES. . . . . . . . . . . . . . . . . . . . . . 6-49
REMOVING THE STEERING KNUCKLES. . . . . . . . . . . . . . . . . . . . . 6-50
CHECKING THE TIE-RODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50
CHECKING THE STEERING KNUCKLES . . . . . . . . . . . . . . . . . . . . . 6-50
INSTALLING THE TIE-RODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50
FRONT ARMS AND FRONT SHOCK ABSORBER ASSEMBLIES . . . . 6-51
REMOVING THE FRONT ARMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
CHECKING THE FRONT ARMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
CHECKING THE FRONT SHOCK ABSORBERS . . . . . . . . . . . . . . . 6-53
CHECKING THE BALL JOINTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54
INSTALLING THE FRONT ARMS . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54
REAR SHOCK ABSORBER, SWINGARM AND DRIVE CHAIN . . . . . . 6-55
HANDLING THE REAR SHOCK ABSORBER . . . . . . . . . . . . . . . . . . 6-57
DISPOSING OF A REAR SHOCK ABSORBER . . . . . . . . . . . . . . . . . 6-57
REMOVING THE REAR SHOCK ABSORBER. . . . . . . . . . . . . . . . . . 6-58
CHECKING THE REAR SHOCK ABSORBER . . . . . . . . . . . . . . . . . . 6-58
REMOVING THE SWINGARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
CHECKING THE SWINGARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-59
CHECKING THE DRIVE CHAIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60
INSTALLING THE SWINGARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
INSTALLING THE DRIVE SPROCKET . . . . . . . . . . . . . . . . . . . . . . . 6-62

CHAPTER 7
ELECTRICAL
ELECTRICAL COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
CHECKING SWITCH CONTINUITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
CHECKING THE SWITCHES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

CHECKING THE BULBS AND BULB SOCKETS . . . . . . . . . . . . . . . . . . 7-5
TYPES OF BULBS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
CHECKING THE CONDITION OF THE BULBS . . . . . . . . . . . . . . . . . 7-5
CHECKING THE CONDITION OF THE BULB SOCKETS . . . . . . . . 7-7
IGNITION SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9
ELECTRIC STARTING SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13
CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13
STARTING CIRCUIT CUT-OFF SYSTEM OPERATION . . . . . . . . . . 7-14
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15
STARTER MOTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19
CHECKING THE STARTER MOTOR . . . . . . . . . . . . . . . . . . . . . . . . . 7-21
ASSEMBLING THE STARTER MOTOR . . . . . . . . . . . . . . . . . . . . . . 7-23
CHARGING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24
CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-25
LIGHTING SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-27
CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-27
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28
CHECKING THE LIGHTING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . 7-29
SIGNAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-31
CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-31
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-32
CHECKING THE SIGNALING SYSTEM. . . . . . . . . . . . . . . . . . . . . . . 7-33

CHAPTER 8
TROUBLESHOOTING
STARTING FAILURE/HARD STARTING . . . . . . . . . . . . . . . . . . . . . . . . 8-1
FUEL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
ELECTRICAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
COMPRESSION SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
POOR IDLE SPEED PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
POOR IDLE SPEED PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . 8-2
POOR MEDIUM AND HIGH-SPEED PERFORMANCE . . . . . . . . . . . . . 8-2
POOR MEDIUM AND HIGH-SPEED PERFORMANCE . . . . . . . . . . . 8-2
FAULTY GEAR SHIFTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
HARD SHIFTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
SHIFT PEDAL DOES NOT MOVE . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
JUMPS OUT GEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

CLUTCH SLIPPING/DRAGGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
CLUTCH SLIPPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
CLUTCH DRAGGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
OVERHEATING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
OVERHEATING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
FAULTY BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
POOR BRAKING EFFECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
SHOCK ABSORBER MALFUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
MALFUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4
UNSTABLE HANDLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
UNSTABLE HANDLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
LIGHTING SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
HEADLIGHT DOES NOT COME ON . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
TAIL/BRAKE LIGHT DOES NOT LIGHT . . . . . . . . . . . . . . . . . . . . . . 8-5
BULB BURNT OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
TAIL/BRAKE LIGHT BULB BURNT OUT . . . . . . . . . . . . . . . . . . . . . 8-5

MACHINE IDENTIFICATION

GEN
INFO

EBS00009

GENERAL INFORMATION
MACHINE IDENTIFICATION
EBS00010

VEHICLE IDENTIFICATION NUMBER
The vehicle identification number
stamped into the left side of the frame.

is

EBS00011

MODEL LABEL
The model label
is affixed to the air filter
case cover. This information will be needed to
order spare parts.

1-1

IMPORTANT INFORMATION

GEN
INFO

EBS00013

IMPORTANT INFORMATION
PREPARATION FOR REMOVAL AND
DISASSEMBLY
1. Before removal and disassembly remove all
dirt, mud, dust and foreign material.
2. Use only the proper tools and cleaning
equipment.
Refer to “SPECIAL TOOLS”.
3. When disassembling always keep mated
parts together. This includes gears, cylinders, pistons and other parts that have
been “mated” through normal wear. Mated
parts must always be reused or replaced as
an assembly.
4. During disassembly, clean all of the parts
and place them in trays in the order of disassembly. This will speed up assembly and
allow for the correct installation of all parts.
5. Keep all parts away from any source of fire.
EBS00014

REPLACEMENT PARTS
1. Use only genuine Yamaha parts for all
replacements. Use oil and grease recommended by Yamaha for all lubrication jobs.
Other brands may be similar in function and
appearance, but inferior in quality.

EBS00015

GASKETS, OIL SEALS AND O-RINGS
1. When overhauling the engine, replace all
gaskets, seals and O-rings. All gasket surfaces, oil seal lips and O-rings must be
cleaned.
2. During reassembly properly oil all mating
parts and bearings, and lubricate the oil
seal lips with grease.

EBS00016

LOCK WASHERS/PLATES AND COTTER
PINS
After removal, replace all lock washers/plates
and cotter pins. After the bolt or nut has
been tightened to specification, bend the lock
tabs along a flat of the bolt or nut.

1-2

1
2
3
4
5
6
7
8

IMPORTANT INFORMATION

GEN
INFO

EBS00017

BEARINGS AND OIL SEALS
Install bearings and oil seals so that the manufacturer’s marks or numbers are visible. When
installing oil seals, lubricate the oil seal lips
with a light coat of lithium-soap-based grease.
Oil bearings liberally when installing, if appropriate.
Oil seal

CAUTION:
Do not spin the bearing with compressed
air because this will damage the bearing
surfaces.
Bearing

EBS00018

CIRCLIPS
Before reassembly, check all circlips carefully
and replace damaged or distorted circlips.
Always replace piston pin clips after one use.
When installing a circlip
, make sure the
sharp-edged corner
is positioned opposite
the thrust
that the circlip receives.
Shaft

1-3

IMPORTANT INFORMATION

GEN
INFO

EBS00019

CHECKING THE CONNECTIONS
Check the leads, couplers, and connectors for
stains, rust, moisture, etc.
1. Disconnect:
• lead
• coupler
• connector
2. Check:
• lead
• coupler
• connector
Moisture → Dry with an air blower.
Rust /stains → Connect and disconnect
several times.
3. Check:
• all connections
Loose connection → Connect properly.
NOTE:
If the pin
on the terminal is flattened, bend it
up.
4. Connect:
• lead
• coupler
• connector
NOTE:
Make sure all connections are tight.

5. Check:
• continuity (with the pocket tester)
Pocket tester
YU-03112-C
Analog pocket tester
YU-03112-C
NOTE:
• If there is no continuity, clean the terminals.
• When checking the wire harness, perform
steps (1) to (3).
• As a quick remedy, use a contact revitalizer
available at most part stores.

1-4

SPECIAL TOOLS

GEN
INFO

EBS00021

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 CAN
P/N. YM-, YU-, YS-, YK-, ACCExcept for US and CAN
P/N. 90890
Tool No.

Tool name/Function

Illustration

Slide hummer bolt
Slide hummer bolt 6 mm
90890-01083
YU-01083-1
This tool is used to remove the rocker arm
shaft.
Weight
YU-01083-3

90890-01084
YU-01083-3
This tool is used to remove the rocker arm
shaft.
Crankcase separating tool
Crankcase separator
90890-01135
YU-01135-B
This tool is used to separate the crankcase.
Ring nut wrench
Spanner wrench
90890-01268
YU-01268
This tool is used to adjusting the front shock
absorbers.
Crankshaft installer pot
Installing pot

YU-90058/YU-90059

90890-01274
YU-90058
These tools are used to install the crankshaft.
Crankshaft installer bolt
Bolt
90890-01275
YU-90060
This tool is used to install the crankshaft.

1-5

SPECIAL TOOLS
Tool No.

Adapter
90890-01383
YU-90062

Tool name/Function

GEN
INFO
Illustration

Adapter (M10)
Adapter #2

This tool is used to install the crankshaft.
Spacer
90890-01288
This tool is used to install the crankshaft.
Piston pin puller set
Piston pin puller

YU-01304

90890-01304
YU-01304
This tool is used to remove the piston pin.
Tappet adjusting tool
Six piece tappet set
90890-01311
YM-A5970
This tool is necessary for adjusting the valve
clearance.
Flywheel puller
Heavy duty puller
90890-01362
YU-33270-B
This tool is used to remove the AC magneto
rotor.
Bolt (M8 × 80 mm)
90890-01359
This tool is used to remove the AC magneto
rotor.
Sheave holder
Primary clutch holder
90890-01701
YS-01880-A

This tool is needed to hold the AC magneto
rotor when loosen or tighten the AC magneto
rotor nut.
Thickness gauge
Narrow gauge set

90890-03079
YM-34483
This tool is used to measure the valve clearance and spark plug gap.

1-6

SPECIAL TOOLS
Tool No.

Tool name/Function
Compression gauge
Engine compression tester

90890-03081
YU-33223
This tool is needed to measure the engine
compression.
Extension
90890-04082
This tool is needed to measure engine compression.
Pocket tester
Analog pocket tester
90890-03112
YU-03112-C
This instrument is needed for checking the
electrical system.
Timing light
Inductive clamp timing light
90890-03141
YU-03141
This tool is necessary for checking ignition
timing.
Valve spring compressor
Compressor
90890-04019
YM-04019

This tool is needed to remove and install the
valve assemblies.
Valve spring compressor attachment
Valve spring compressor adapter (26 mm)

90890-01243
YM-01253-1
This tool is needed to remove and install the
valve assemblies.
Universal clutch holder
90890-04086
YM-91042
This tool is needed to hold the clutch carrier
when removing or installing the carrier nut.
Valve guide remover (φ6)
Valve guide remover (6.0 mm)
90890-04064
YM-04064-A
This tool is needed to remove and install the
valve guides.

1-7

GEN
INFO
Illustration

SPECIAL TOOLS
Tool No.

Tool name/Function
Valve guide installer (φ6)
Valve guide installer (6.0 mm)

90890-04065
YM-04065-A
This tool is needed to install the valve guides.
Valve guide reamer (φ6)
Valve guide reamer (6.0 mm)
90890-04066
YM-04066
This tool is needed to rebore the new valve
guides.
Valve lapper
Valve lapping tool
90890-04101
YM-A8998
This tool is needed to remove and install the
valve lifters.
PTT wrench 46
90890-06588
This tool is needed to loosen or tighten the
rear axle nut.
Axle nut wrench (46 mm)
YM-37134
This tool is needed to loosen or tighten the
rear axle nut.
Ignition checker
Opama pet-4000 spark checker
90890-06754
YM-34487
This instrument is necessary for checking the
ignition system components.
Digital tachometer
90890-06760
YU-39951-B
This tool is needed for observing engine rpm.
Yamaha bond No. 1215
(Three Bond No. 1215®)
90890-85505
This bond is used on crankcase mating surfaces, etc.

1-8

GEN
INFO
Illustration

GENERAL SPECIFICATIONS

SPEC

EBS01001

SPECIFICATIONS
GENERAL SPECIFICATIONS
Item
Model code

Dimensions
Overall length
Overall width
Overall height
Seat height
Wheelbase
Minimum ground clearance
Minimum turning radius
Basic weight
With oil and full fuel tank
Engine
Engine type
Cylinder arrangement
Displacement
Bore × stroke
Compression ratio
Engine idle speed
Intake vacuum
Oil temperature
Standard compression pressure (at sea level)
Starting system
Lubrication system
Oil type or grade
Engine oil

Oil capacity
Engine oil
Periodic oil change
With oil filter replacement
Total amount
Air filter

Standard
4D31
4D35
4D39
1,625 mm (64.0 in)
1,070 mm (42.1 in)
1,040 mm (40.9 in)
730 mm (28.7 in)
1,110 mm (43.7 in)
100 mm (3.94 in)
2,900 mm (114.2 in)
150 kg (331 lb)
Air-cooled 4-stroke, SOHC
Forward-inclined single cylinder
249 cm3 (15.19 cu in)
74.0 × 58.0 mm (2.91 × 2.28 in)
9.5 : 1
1,500 ~ 1,600 r/min
34 kPa (255 mmHg, 10.0 inHg)
55 ~ 65 °C
1,100 kPa (11.2 kg/cm2, 160 psi)/720 r/min
Electric starter
Wet sump
YAMALUBE4, SAE 5W-30 or SAE 10W-30 or
SAE 20W-40
API service, SG type or higher, JASO standard
MA

1.25 L (1.10 Imp qt, 1.32 US qt)
1.35 L (1.19 Imp qt, 1.43 US qt)
1.60 L (1.41 Imp qt, 1.69 US qt)
Wet type element

2-1

GENERAL SPECIFICATIONS
Item
Fuel
Type
Fuel tank capacity
Fuel reserve amount
Carburetor
Type/quantity
Manufacturer
Spark plug
Type/manufacturer
Spark plug gap
Clutch type
Transmission
Primary reduction system
Primary reduction ratio
Secondary reduction system
Secondary reduction ratio
Transmission type
Operation
Gear ratio
1st gear
2nd gear
3rd gear
4th gear
5th gear
Chassis
Frame type
Caster angle
Camber angle
Kingpin angle
Trail
Tread (STD)

front
rear
Toe-in (with tires touching the ground)
Tire
Type
Size
front
rear
Manufacturer
front
rear
Type
front
rear
Tire pressure (cold tire)
Maximum load*
Off-road riding
front
rear
*Load in total weight of cargo, rider and
accessories

SPEC

Standard
Unleaded gasoline only
9.0 L (1.97 Imp gal, 2.37 US gal)
1.0 L (0.22 Imp gal, 0.26 US gal)
BSR29 × 1
MIKUNI
DR7EA/NGK
0.6 ~ 0.7 mm (0.024 ~ 0.028 in)
Wet, multiple-disc
Spur gear
76/22 (3.455)
Chain drive
38/14 (2.714)
Constant mesh, 5-speed
Left foot operation
37/13 (2.846)
33/18 (1.833)
29/21 (1.381)
27/24 (1.125)
28/29 (0.966)
Steel tube frame
6°
–1.5°
14.8°
23.0 mm (0.91 in)
826 mm (32.52 in)
824 mm (32.44 in)
9 ~ 19 mm (0.35 ~ 0.75 in)
Tubeless
AT20 × 7-10
AT19 × 10-9
DUNLOP
DUNLOP
KT201
KT205A
100 kg (220 lb)
27.5 kPa (0.28 kg/cm2, 4.0 psi)
27.5 kPa (0.28 kg/cm2, 4.0 psi)

2-2

1
2
3
4
5
6
7
8

GENERAL SPECIFICATIONS
Item
Brake
Front brake
Rear brake
Suspension
Front suspension
Rear suspension
Shock absorber
Front shock absorber
Rear shock absorber
Wheel travel
Front wheel travel
Rear wheel travel
Electrical
Ignition system
Generator system
Battery type
Battery capacity
Headlight type
Bulb voltage/wattage × quantity
Headlight
Tail/brake light
Indicator lights
Neutral

SPEC

Standard
type
operation
type
operation

Dual disc brake
Right hand operation
Single disc brake
Right foot operation
Double wishbone
Swingarm
Coil spring/oil damper
Coil spring/gas-oil damper
190 mm (7.48 in)
200 mm (7.87 in)
DC-CDI
AC magneto
YTZ7S
12 V 6.0 Ah
Krypton bulb
12 V 30 W/30 W × 2
12 V 5 W/21 W × 1 (4D31)
12 V 0.5 W/3.9 W × 1 (4D35, 4D39)
12 V 1.7 W × 1

2-3

ENGINE SPECIFICATIONS

SPEC

EBS01002

ENGINE SPECIFICATIONS
Item

Standard

Cylinder head
Volume
Warp limit

20.50 ~ 21.50 cm3 (1.25 ~ 1.31 cu.in)
•••

Cylinder
Bore size

Chain drive (Right)

“A”
“B”

Exhaust

•••
0.05 mm
(0.0020 in)

74.000 ~ 74.016 mm (2.9134 ~ 2.9140 in) 74.100 mm
(2.9173 in)

Camshaft
Drive method
Camshaft lobe dimensions

Intake

Limit

“A”
“B”

Camshaft runout limit

Timing chain
Timing chain type/No. of links
Timing chain adjustment method
Rocker arm/rocker arm shaft
Rocker arm inside diameter
Rocker arm shaft outside diameter
Rocker-arm-to-rocker-arm-shaft
clearance

•••

36.890 ~ 36.990 mm (1.4524 ~ 1.4563 in) 36.790 mm
(1.4484 in)
30.111 ~ 30.211 mm (1.1855 ~ 1.1894 in) 30.011 mm
(1.1815 in)
36.891 ~ 36.991 mm (1.4524 ~ 1.4563 in) 36.791 mm
(1.4485 in)
30.092 ~ 30.192 mm (1.1847 ~ 1.1887 in) 29.992 mm
(1.1808 in)
0.03 mm
•••
(0.0012 in)

DID SCR-0404 SV/104
Automatic

•••
•••

12.000 ~ 12.018 mm (0.4724 ~ 0.4731 in) 12.036 mm
(0.4739 in)
11.981 ~ 11.991 mm (0.4717 ~ 0.4721 in) 11.950 mm
(0.4705 in)
0.009 ~ 0.037 mm (0.0004 ~ 0.0015 in)
•••

2-4

ENGINE SPECIFICATIONS
Item
Valve, valve seat, valve guide
Valve clearance (cold)
IN
EX
Valve dimensions

Head Diameter

“A” head diameter
“B” face width
“C” seat width

“D” margin thickness
Stem outside diameter

Guide inside diameter

Stem-to-guide clearance

Standard

Limit
•••
•••

0.05 ~ 0.10 mm (0.0020 ~ 0.0039 in)
0.10 ~ 0.15 mm (0.0039 ~ 0.0059 in)

Face Width

Seat Width

Margin Thickness

IN
EX
IN
EX
IN

33.90 ~ 34.10 mm (1.3346 ~ 1.3425 in)
28.40 ~ 28.60 mm (1.1181 ~ 1.1260 in)
2.26 mm (0.0890 in)
2.26 mm (0.0890 in)
0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)

EX

0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)

IN
EX
IN

0.80 ~ 1.20 mm (0.0315 ~ 0.0472 in)
0.80 ~ 1.20 mm (0.0315 ~ 0.0472 in)
5.975 ~ 5.990 mm (0.2352 ~ 0.2358 in)

EX

5.960 ~ 5.975 mm (0.2346 ~ 0.2352 in)

IN

6.000 ~ 6.012 mm (0.2362 ~ 0.2367 in)

EX

6.000 ~ 6.012 mm (0.2362 ~ 0.2367 in)

IN

0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in)

EX

0.025 ~ 0.052 mm (0.0010 ~ 0.0020 in)
•••

Valve stem runout
Valve seat width

SPEC

IN

0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)

EX

0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)

2-5

•••
•••
•••
•••
1.6 mm
(0.06 in)
1.6 mm
(0.06 in)
•••
•••
5.945 mm
(0.234 in)
5.930 mm
(0.233 in)
6.050 mm
(0.238 in)
6.050 mm
(0.238 in)
0.080 mm
(0.003 in)
0.100 mm
(0.004 in)
0.01 mm
(0.0004 in)
1.6 mm
(0.06 in)
1.6 mm
(0.06 in)

ENGINE SPECIFICATIONS
Item
Valve spring
Inner spring
Free length

Installed length
(valve closed)
Spring rate K1
K2
K1
K2
Compressed spring force
(installed)

Standard

Direction of winding
(top view)
Outer spring
Free length

Installed length
(valve closed)
Spring rate K1
Spring rate K2
Spring rate K1
Spring rate K2
Compressed spring force
(installed)

Limit

IN

36.17 mm (1.42 in)

EX

36.17 mm (1.42 in)

IN
EX
IN
IN
EX
EX

30.50 mm (1.20 in)
30.50 mm (1.20 in)
14.70 N/mm (1.50 kg/mm, 83.94 lb/in)
19.00 N/mm (1.94 kg/mm, 108.49 lb/in)
14.70 N/mm (1.50 kg/mm, 83.94 lb/in)
19.00 N/mm (1.94 kg/mm, 108.49 lb/in)

•••
•••
•••
•••
•••
•••

IN

•••

IN

75.00 ~ 91.70 N
(7.65 ~ 9.35 kg, 16.86 ~ 20.62 lb)
75.00 ~ 91.70 N
(7.65 ~ 9.35 kg, 16.86 ~ 20.62 lb)
•••

EX

•••

IN
EX

Counter clockwise
Counter clockwise

•••
•••

IN

36.63 mm (1.44 in)

EX

36.63 mm (1.44 in)

34.80 mm
(1.37 in)
34.80 mm
(1.37 in)

IN
EX
IN
IN
EX
EX

32.00 mm (1.26 in)
32.00 mm (1.26 in)
30.90 N/mm (3.15 kg/mm, 176.44 lb/in)
40.80 N/mm (4.16 kg/mm, 232.97 lb/in)
30.90 N/mm (3.15 kg/mm, 176.44 lb/in)
40.80 N/mm (4.16 kg/mm, 232.97 lb/in)

•••
•••
•••
•••
•••
•••

IN

128.50 ~ 157.90 N
(13.10 ~ 16.10 kg, 28.89 ~ 35.50 lb)
128.50 ~ 157.90 N
(13.10 ~ 16.10 kg, 28.89 ~ 35.50 lb)

•••

EX
Tilt limit

SPEC

EX

2-6

34.36 mm
(1.35 in)
34.36 mm
(1.35 in)

•••
2.5°/1.60 mm
(2.5°/0.063 in)
2.5°/1.60 mm
(2.5°/0.063 in)

•••

ENGINE SPECIFICATIONS
Item
Tilt limit

Direction of winding
(top view)

SPEC

Standard
IN

•••

EX

•••

IN
EX

Clockwise
Clockwise

Piston
Piston to cylinder clearance

Limit
2.5°/1.60 mm
(2.5°/0.063 in)
2.5°/1.60 mm
(2.5°/0.063 in)

•••
•••

Piston size “D”

0.15 mm
(0.006 in)
73.983 ~ 73.998 mm (2.9127 ~ 2.9133 in) • • •

Measuring point “H”
Piston off set
Offset direction
Piston pin bore inside diameter

5.0 mm (0.20 in)
0.25 mm (0.0098 in)
Intake side
17.002 ~ 17.013 mm (0.6694 ~ 0.6698 in)

Piston pin outside diameter
Piston-pin-to-piston-pin-bore
clearance

0.010 ~ 0.025 mm (0.0004 ~ 0.0010 in)

•••
•••
•••
17.043 mm
(0.6710 in)
16.991 ~ 17.000 mm (0.6689 ~ 0.6693 in) 16.971 mm
(0.6681 in)
0.002 ~ 0.022 mm (0.0001 ~ 0.0009 in)
0.072 mm
(0.0028 in)

2-7

ENGINE SPECIFICATIONS
Item

SPEC

Standard

Limit

Piston rings
Top ring

Type
Dimensions (B × T)
End gap (installed)

Barrel
0.90 × 2.75 mm (0.035 × 0.108 in)
0.19 ~ 0.31 mm (0.007 ~ 0.012 in)

Side clearance

0.030 ~ 0.065 mm (0.0012 ~ 0.0026 in)

•••
•••
0.56 mm
(0.022 in)
0.115 mm
(0.0045 in)

2nd ring

Type
Dimensions (B × T)
End gap (installed)

Taper
0.80 × 2.80 mm (0.031 × 0.110 in)
0.30 ~ 0.45 mm (0.012 ~ 0.018 in)

Side clearance

0.020 ~ 0.055 mm (0.0008 ~ 0.0022 in)

•••
•••
0.80 mm
(0.032 in)
0.115 mm
(0.0045 in)

Oil ring

Dimensions (B × T)
End gap (installed)
Crankshaft

1.50 × 2.60 mm (0.059 × 0.102 in)
0.10 ~ 0.35 mm (0.004 ~ 0.014 in)

•••
•••

Crank width “A”
Runout limit C1

69.25 ~ 69.30 mm (2.726 ~ 2.728 in)
•••

•••
0.03 mm
(0.0012 in)
0.03 mm
(0.0012 in)
0.50 mm
(0.0197 in)
•••

C2

•••

Big end side clearance “D”

0.350 ~ 0.650 mm (0.0138 ~ 0.0256 in)

Big end radial clearance “E”

0.010 ~ 0.025 mm (0.0004 ~ 0.0010 in)

2-8

ENGINE SPECIFICATIONS
Item
Balancer
Balancer drive method
Clutch
Friction plate 1 (inside dia.: 104.5 ~
105.5 mm)
Thickness

SPEC

Standard

Limit

Gear

•••

2.9 ~ 3.1 mm (0.114 ~ 0.122 in)

2.8 mm
(0.110 in)
•••

Quantity
Friction plate 2 (inside dia.: 104.5 ~
105.5 mm)
Thickness

4

Quantity
Clutch plate
Thickness
Quantity
Max. warpage

2
1.5 ~ 1.7 mm (0.059 ~ 0.067 in)
5
•••

•••
•••
0.2 mm
(0.0079 in)

Clutch spring
Free length

47.8 mm (1.88 in)

Quantity
Clutch release method
Push rod 2 bending limit

5
Inner push, cam push
•••

45.4 mm
(1.79 in)
•••
•••
0.1 mm
(0.004 in)

Transmission
Main axle runout limit

•••

Drive axle runout limit

•••

Main axle assembly width
Shifter
Shifter type
Max. shift fork guide bar bending

102.2 ~ 102.4 mm (4.02 ~ 4.03 in)
Shift drum and guide bar
•••

Air filter oil grade

Foam air filter oil or equivalent oil

2.9 ~ 3.1 mm (0.114 ~ 0.122 in)

2-9

2.8 mm
(0.110 in)
•••

0.06 mm
(0.0024 in)
0.06 mm
(0.0024 in)
•••
•••
0.05 mm
(0.002 in)
•••

ENGINE SPECIFICATIONS
Item
Carburetor
I. D. mark
Main jet
(M.J)
Main air jet
(M.A.J)
Jet needle
(J.N)
Needle jet
(N.J)
Pilot air jet 1
(P.A.J.1)
Pilot air jet 2
(P.A.J.2)
Pilot outlet
(P.O)
Pilot jet
(P.J)
Bypass 1
(B.P.1)
Bypass 2
(B.P.2)
Bypass 3
(B.P.3)
Valve seat size
(V.S)
Starter jet 1
(G.S.1)
Starter jet 2
(G.S.2)
Throttle valve size
(THV)
Float height
(F.H)
Oil filter type
Oil pump
Oil pump type
Inner-rotor-to-outer-rotor-tip clearance

SPEC

Standard
4D31 00
#133.8
#140
5DH66-1
P-0M
#85
#170
ø0.9
#25
ø0.8
ø0.8
ø0.8
ø2.0
#55
#0.5
#100
13.0 mm (0.51 in)
Wire mesh

Limit
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••
•••

•••
0.23 mm
(0.0091 in)
Outer-rotor-to-oil-pump-housing
0.100 ~ 0.151 mm (0.0039 ~ 0.0059 in)
0.22 mm
clearance
(0.0087 in)
Oil-pump-housing-to-inner-and-outer- 0.04 ~ 0.09 mm (0.0016 ~ 0.0035 in)
0.16 mm
rotor clearance
(0.0063 in)
Oil pressure (hot)
3.0 kPa, 0.03 kg/cm2, 0.44 psi/1550 r/min • • •
Pressure check location
HEAD CYLINDER
•••
Trochoid
0.15 mm (0.0059 in)

2-10

CHASSIS SPECIFICATIONS

SPEC

EBS01003

CHASSIS SPECIFICATIONS
Item
Front suspension
Shock absorber travel
Spring free length
Spring rate
Spring stroke
Optional spring
Rear suspension
Shock absorber assembly travel
Spring free length
Spring rate
Stroke
Optional spring
Swingarm
Free play limit
radial
axial

Standard

Limit

90.7 mm (3.57 in)
248.5 mm (9.78 in)
23.0 N/mm (2.34 kg/mm, 131.26 lb/in)
0.0 ~ 90.7 mm (0.0 ~ 3.57 in)
No

•••
•••
•••
•••
•••

87.0 mm (3.43 in)
240.5 mm (9.47 in)
54.0 N/mm (5.50 kg/mm, 308.18 lb/in)
0 ~ 87.0 mm (0 ~ 3.43 in)
No

•••
•••
•••
•••
•••

•••

1.0 mm
(0.04 in)
1.0 mm
(0.04 in)

•••

Rear axle
Rear axle runout

•••

1.5 mm
(0.06 in)

Front wheel
Type
Rim size
Rim material
Rim runout limit

radial

Panel wheel
10 × 5.5 AT
Aluminum
•••

lateral

•••

•••
•••
•••
2.0 mm
(0.08 in)
2.0 mm
(0.08 in)

radial

Panel wheel
9 × 8.5 AT
Aluminum
•••

lateral

•••

Rear wheel
Type
Rim size
Rim material
Rim runout limit

Drive chain
Type/manufacturer
Link quantity
Drive chain slack
Maximum 15-links section

520V/DAIDO
91
45.0 ~ 55.0 mm (1.77 ~ 2.17 in)
239.3 mm (9.42 in)

2-11

•••
•••
•••
2.0 mm
(0.08 in)
2.0 mm
(0.08 in)
•••
•••
•••
•••

CHASSIS SPECIFICATIONS
Item
Front disc brake
Type
Disc outside diameter × thickness

SPEC

Standard
Dual
161.0 × 3.5 mm (6.34 × 0.14 in)

Brake disk maximum deflection
Pad thickness inner

4.4 mm (0.17 in)

Pad thickness outer

4.5 mm (0.18 in)

Master cylinder inside diameter
Caliper cylinder inside diameter
Brake fluid type
Rear disc brake
Type
Disc outside diameter × thickness

12.7 mm (0.50 in)
27 mm (1.06 in)
DOT 4
Single
200.0 × 4.0 mm (7.87 × 0.16 in)

Limit
•••
3.0 mm
(0.12 in)
0.15 mm
(0.006 in)
1.5 mm
(0.06 in)
1.5 mm
(0.06 in)
•••
•••
•••

Pad thickness inner

4.2 mm (0.17 in)

Pad thickness outer

4.2 mm (0.17 in)

Master cylinder inside diameter
Caliper cylinder inside diameter
Brake fluid type
Lever and pedal
Brake lever free play
Brake pedal position (top of the brake
pedal to top of the frame)
Parking brake cable end length
Clutch lever free play (lever end)
Throttle lever free play
Speed limiter length
Shift pedal height

12.7 mm (0.50 in)
33.96 mm (1.34 in)
DOT 4

•••
3.5 mm
(0.14 in)
0.15 mm
(0.006 in)
1.0 mm
(0.04 in)
1.0 mm
(0.04 in)
•••
•••
•••

0 mm (0 in)
40.0 mm (1.57 in)

•••
•••

64 ~ 68 mm (2.52 ~ 2.68 in)
5 ~ 10 mm (0.20 ~ 0.39 in)
2 ~ 4 mm (0.08 ~ 0.16 in)
Less than 12 mm (0.47 in)
15.2 mm (0.60 in)

•••
•••
•••
•••
•••

Brake disk maximum deflection

2-12

ELECTRICAL SPECIFICATIONS

SPEC

EBS01004

ELECTRICAL SPECIFICATIONS
Item

Standard

Voltage
Ignition system
Ignition timing (B.T.D.C.)
Advanced timing (B.T.D.C.)
Advancer type
CDI
CDI unit model/manufacturer
Pickup coil resistance/color
Ignition coil
Model/manufacturer
Minimum ignition spark gap
Primary winding resistance
Secondary winding resistance
Spark plug cap
Material
Resistance
Charging system
Type
Model/manufacturer
Nominal output
Charging coil resistance/color
Rectifier/regulator
Type
Model/manufacturer
No load regulated voltage
Rectifier capacity
Withstand voltage
Battery
Specific gravity
Electric starter system
Type
Starter motor
Model/manufacturer
Output
Armature coil resistance
Brush overall length
Spring force

Limit

12 V

•••

10.0°/1,550 r/min
24.4°/5,000 r/min
Digital type

•••

4D3/YAMAHA
248 ~ 372 Ω at 20°C (68°F) red–white

•••
•••

2JN/YAMAHA
6.0 mm (0.24 in)
0.18 ~ 0.28 Ω at 20°C (68°F)
6.32 ~ 9.48 kΩ at 20°C (68°F)

•••
•••
•••
•••

•••

Resin
10.0 kΩ

(DC)
(DC)

AC magneto
F5XT/YAMAHA
14 V 190 W at 5,000 r/min
0.688 ~ 1.032 Ω at 20°C (68°F)
white–white

•••
•••
•••
•••

Semi conductor-short circuit
SH640E-11/SHINDENGEN
14.1 ~ 14.9 V
14.0 A
200.0 V

•••
•••
•••
•••

1.310
Constant mesh type

•••

4D3/YAMAHA
0.40 kW
0.013 ~ 0.015 Ω at 20°C (68°F)
10.0 mm (0.39 in)

•••
•••
•••
3.5 mm
(0.14 in)
•••

Commutator diameter

5.52 ~ 8.28 N
(563 ~ 844 gf, 19.85 ~ 29.78 oz)
22.0 mm (0.87 in)

Mica undercut

1.5 mm (0.06 in)

2-13

21.0 mm
(0.83 in)
•••

ELECTRICAL SPECIFICATIONS
Item
Starter relay
Model/manufacturer
Amperage rating
Coil winding resistance
Headlight relay
Headlight relay
Model/manufacturer
Coil resistance
Circuit breaker
Type
Amperage for individual circuit
Fuse
Reserve

SPEC

Standard

Limit

A4616-051/JIDECO
180 A
4.18 ~ 4.62 Ω

•••
•••
•••

G8HN-1C4T-DJ-Y52/OMRON
94.5 Ω ~ 115.5 Ω

•••
•••

Fuse

•••

15 A × 1
15 A × 1

•••
•••

2-14

TIGHTENING TORQUES

SPEC

EBS01005

TIGHTENING TORQUES
ENGINE TIGHTENING TORQUES
Tightening torque

Part
name

Thread
size

Q’ty

Bolt

M8

4

Cylinder head
Camshaft lock plate
Cylinder head side cover (1 and 2)
Cylinder head side cover 3
Cylinder head breather plate
Spark plug
Cylinder head stud bolt
Oil gallery bolt
Carburetor joint
Plate, 2
Cylinder
Left crankcase cover
Pickup coil rotor
Balancer weight gear

Bolt
Bolt
Bolt
Bolt
Bolt
—
Stud bolt
Bolt
Bolt
Bolt
Bolt
Bolt
Bolt
Nut

M8
M6
M55
M6
M6
M12
M8
M6
M6
M6
M6
M6
M10
M12

2
2
2
2
2
1
2
1
2
2
2
9
1
1

Valve clearance adjusting locknut
Camshaft sprocket
Timing chain tensioner
Timing chain tensioner cap bolt
Timing chain guide (intake side)
Oil filter element cover
Oil delivery pipe

Nut
Bolt
Bolt
Bolt
Bolt
Bolt
Union
bolt
Union
bolt
Screw
Screw
Screw
Nut
Bolt
Bolt
Bolt
Bolt
Bolt
Bolt
Bolt
Bolt
Bolt
Bolt
Nut

M6
M10
M6
M6
M6
M6
M10

2
1
2
1
2
3
1

Remarks
Nm m•kg ft•lb
E
24
2.4
18
See NOTE *1
20
2.0
15
8
0.8
5.9
18
1.8
13
10
1.0
7.4
10
1.0
7.4
18
1.8
13
15
1.5
11
7
0.7
5.2
10
1.0
7.4
12
1.2
8.9
10
1.0
7.4
10
1.0
7.4
60
6.0
44
55
5.5
41 Use a lock
washer.
14
1.4
10
60
6.0
44
10
1.0
7.4
8
0.8
5.9
8
0.8
5.9
10
1.0
7.4
20
2.0
15

M8

1

17

1.7

13

M6
M4
M4
M8
M8
M8
M5
M6
M6
M12
M6
M6
M6
M8
M16

3
2
1
2
1
2
1
13
12
1
1
1
3
3
1

6
4
4
18
20
34
7
10
10
20
10
10
10
30
80

0.6
0.4
0.4
1.8
2.0
3.4
0.7
1.0
1.0
2.0
1.0
1.0
1.0
3.0
8.0

4.4
3.0
3.0
13
15
25
5.2
7.4
7.4
15
7.4
7.4
7.4
22
59

Part to be tightened
Cylinder head (upper)

Oil delivery pipe and cylinder
Oil pump assembly
Carburetor joint clamp screw (front)
Carburetor joint clamp screw (rear)
Exhaust pipe nut
Muffler joint
Muffler
Left crankcase cover
Right crankcase cover
Crankcase
Oil drain bolt
Ground lead, clutch cable holder
Neutral switch lead clamp
Starter idle gear cover
Starter clutch
Primary drive gear nut

2-15

Use a lock
washer.

TIGHTENING TORQUES
Part to be tightened
Clutch boss nut
Clutch spring
Push lever adjusting screw locknut
Push lever shaft
Chain case cover
Drive sprocket nut
Stopper lever
Shift pedal
Neutral switch
Starter motor
Stator coil
Pickup coil

Part
name

Thread
size

Q’ty

Nut

M16

Screw
Nut
Bolt
Bolt
Nut
Bolt
Bolt
—
Bolt
Bolt
Bolt

SPEC

Tightening torque

1

Nm
75

m•kg
7.5

ft•lb
55

M6
M6
M8
M10
M18

5
1
1
2
1

8
8
12
10
110

0.8
0.8
1.2
1.0
11.0

5.9
5.9
8.9
7.4
81

M6
M6
M10
M6
M6
M6

1
1
1
2
3
2

10
10
20
10
10
10

1.0
1.0
2.0
1.0
1.0
1.0

7.4
7.4
15
7.4
7.4
7.4

NOTE:
*1: Apply oil to the bearing surface of (upper) cylinder head bolt.
Further, apply molybdenum disulfide grease to thread part.

2-16

Remarks
Use a lock
washer.

Use a lock
washer.

TIGHTENING TORQUES

SPEC

EBS01006

CHASSIS TIGHTENING TORQUES
Part to be tightened

Thread size

Tightening torque

Engine upper stay and frame
Engine upper stay and engine
Engine lower stay and engine
Engine and frame
Engine lower stay and frame
Swingarm pivot shaft and frame
Rear shock absorber and frame
Rear shock absorber locknut
Rear axle pinch bolt
Front shock absorber and frame
Front shock absorber and lower front arm
Upper front arm and frame
Lower front arm and frame
Steering stem and frame
Steering stem bushing and frame

M8
M10
M10
M10
M8
M14
M12
M20
M8
M10
M10
M10
M10
M10
M8

Nm
33
66
40
66
33
100
55
42
21
48
48
45
45
35
23

Steering stem and handlebar holder
Tie-rod end and locknut
Steering knuckle and front wheel hub
Steering knuckle and front arm (upper and
lower)
Steering knuckle and tie-rod ball joint
Steering stem and tie-rod ball joint
Fuel tank and fuel cock
Fuel tank and frame
Front wheel and front wheel hub
Steering knuckle and front brake caliper bracket
Front brake disc and front wheel hub
Rear axle and rear wheel hub
Rear brake caliper and brake caliper bracket
Rear wheel and rear wheel hub
Driven sprocket and sprocket bracket
Front brake pipe nut
Front brake master cylinder and handlebar
Clutch lever holder and handlebar
Parking brake assembly and clutch lever holder

M8
M10
M14
M10

20
15
70
25

2.0
1.5
7.0
2.5

Remarks
ft•lb
24
49
30
49
24
74
41
31
15
35
35
33
33
26
17 Use a lock
washer.
15
11
52
18

M10
M10
M6
M6
M10
M8
M8
M14
M8
M10
M10
M10
M6
M5
M6

25
25
4
7
45
28
28
120
34
45
55
19
7
4
7

2.5
2.5
0.4
0.7
4.5
2.8
2.8
12
3.4
4.5
5.5
1.9
0.7
0.4
0.7

18
18
3.0
5.2
33
21
21
89
25
33
41
14
5.2
3.0
5.2

2-17

m•kg
3.3
6.6
4.0
6.6
3.3
10
5.5
4.2
2.1
4.8
4.8
4.5
4.5
3.5
2.3

TIGHTENING TORQUES
Part to be tightened

Thread size

Tightening torque

Front brake master cylinder and brake lever
Throttle assembly and handlebar
Front brake master cylinder and brake hose
Brake hose joint and frame
Bleed screw
Front brake pad retaining bolt
Front brake caliper and brake hose
Rear brake caliper retaining bolt
Parking brake case and caliper
Rear axle ring nut
Rear axle ring nut set bolt
Rear brake pad retaining bolt

M6
M5
M10
M6
M8
M10
M10
M8
M8
M33
M6
M8

Nm
6
4
27
10
5
17
27
17
22
140
7
17

Rear brake caliper and brake hose
Rear brake master cylinder and frame
Rear brake master cylinder and brake hose
Parking brake adjusting bolt and locknut
Rear brake disc and brake disc bracket
Rear brake fluid reservoir, cover and bracket
Front bumper and frame
Front fender stay and frame
Side cover and frame
Rear fender and frame
Rear fender, air filter case and frame
Rear fender and rear fender stay
Front fender stay and front fender
Rear carrier bar and frame
Footrest and frame
Foot protector stay foot protector
Foot protector stay foot protector
Foot protector stay and frame
Foot protector stay and footrest
Battery cover, air filter case and frame
Headlight and frame
Tail/brake light bracket and air filter case
Drive chain guide roller and frame
Engine skid plate and frame

M10
M8
M10
M8
M8
M6
M8
M6
M6
M6
M6
M6
M6
M8
M10
M6
M5
M8
M8
M6
M6
M6
M8
M6

31
20
31
15
28
7
31
7
7
7
7
7
7
31
73
7
6
17
17
7
7
4
23
7

2-18

SPEC

m•kg
0.6
0.4
2.7
1.0
0.5
1.7
2.7
1.7
2.2
14
0.7
1.7
3.1
2.0
3.1
1.5
2.8
0.7
3.1
0.7
0.7
0.7
0.7
0.7
0.7
3.1
7.3
0.7
0.6
1.7
1.7
0.7
0.7
0.4
2.3
0.7

Remarks
ft•lb
4.4
3.0
20
7.4
3.7
13
20
13
16
103
5.2
13 Use a lock
washer.
23
15
23
11
21
5.2
23
5.2
5.2
5.2
5.2
5.2
5.2
23
54
5.2
4.4
13
13
5.2
5.2
3.0
17
5.2

HOW TO USE THE CONVERSION TABLE/
GENERAL TIGHTENING TORQUE SPECIFICATIONS

SPEC

EBS00022

EBS00023

HOW TO USE THE CONVERSION
TABLE

GENERAL TIGHTENING TORQUE
SPECIFICATIONS

All specification data in this manual are listed
in SI and METRIC UNITS.
Use this table to convert METRIC unit data to
IMPERIAL unit data.
Ex.

This chart specifies tightening torques for
standard fasteners with a standard ISO thread
pitch. Tightening torque specifications for special components or assemblies are provided
for each chapter of this manual. To avoid
warpage, tighten multi-fastener assemblies in
a crisscross pattern and progressive stages
until the specified tightening torque is reached.
Unless otherwise specified, tightening torque
specifications require clean, dry threads. Components should be at room temperature.

METRIC

MULTIPLIER

IMPERIAL

** mm

×

0.03937

=

** in

2 mm

×

0.03937

=

0.08 in

CONVERSION TABLE
METRIC TO IMPERIAL
Metric unit

Multiplier

Imperial unit

Torque

m•kg
m•kg
cm•kg
cm•kg

7.233
86.794
0.0723
0.8679

ft•lb
in•lb
ft•lb
in•lb

Weight

kg
g

2.205
0.03527

lb
oz

Speed

km/hr

0.6214

mph

Distance

km
m
m
cm
mm

0.6214
3.281
1.094
0.3937
0.03937

mi
ft
yd
in
in

Volume/
Capacity

cc (cm3)
cc (cm3)
lt (liter)
lt (liter)

0.03527
0.06102
0.8799
0.2199

oz (IMP liq.)
cu•in
qt (IMP liq.)
gal (IMP liq.)

Misc.

kg/mm
kg/cm2
Centigrade
(°C)

55.997
14.2234
9/5+32

lb/in
psi (lb/in2)
Fahrenheit
(°F)

A: Distance between flats
B: Outside thread diameter

2-19

A
(nut)

B
(bolt)

10 mm

General tightening
torques
Nm

m•kg

ft•lb

6 mm

6

0.6

4.3

12 mm

8 mm

15

1.5

11

14 mm

10 mm

30

3.0

22

17 mm

12 mm

55

5.5

40

19 mm

14 mm

85

8.5

61

22 mm

16 mm

130

13.0

94

LUBRICATION POINTS AND LUBRICANT TYPES

SPEC

EBS00024

LUBRICATION POINTS AND LUBRICANT TYPES
ENGINE
Lubrication point

Lubricant

Oil seal lips
O-rings
Bearings
Cylinder head bolts (bearing surface of bolts)
Cylinder head bolts (thread part)
Cylinder body surface
Crankshaft journals
Connecting rod small end and big end
Piston pin
Piston surface
Boss periphery
Valve stems (intake and exhaust)
Valve stem ends (intake and exhaust)
Rocker arm shafts (intake and exhaust)
Camshaft
Valve rocker arms
Oil pump rotors (inner and outer) and oil pump housing and shaft
Starter idler gears 1
Starter idler gears 2
Starter wheel gear
Push rods
Clutch housing (primary driven gear)
Push lever shaft
Push rod ball
Drive axle
Main axle
Transmission gears (inside and end)
Shift fork guide bar
Shift drum
Shift shaft

2-20

E
E

E
E
E
E
E
E
M
M

E
M

E
E
E
E

E
E

M
M
M

E
E
E

LUBRICATION POINTS AND LUBRICANT TYPES
Lubrication point
Crankcase mating surfaces

AC magneto lead grommet (AC magneto cover)

2-21

SPEC
Lubricant
Sealant
(Three Bond No.1215®)
Yamaha bond
No.1215
Sealant
(Three Bond No.1215®)
Yamaha bond
No.1215

OIL FLOW DIAGRAMS
EBS00026

OIL FLOW DIAGRAMS
Camshaft
Oil filter element
Oil pump
Oil strainer

Oil filter

Oil cooler
Pin,
with hole

Cylinder
head
Oil pump

Drive axle

Main axle
Crank
shaft

Cam shaft
Oil strainer

Oil pan

2-22

SPEC

OIL FLOW DIAGRAMS
Camshaft
Drive axle
Main axle
Push lever shaft
Oil pump assembly
Oil strainer
Crankshaft assembly
Oil filter element

2-23

SPEC

OIL FLOW DIAGRAMS
Oil cooler
Oil hose 1
Oil hose 2

2-24

SPEC

CABLE ROUTING
EBS00028

CABLE ROUTING
Front brake hose
Front brake light switch lead
Throttle cable
Plastic band
Clutch cable
Parking brake cable
Clutch switch lead
Handlebar switch lead

2-25

SPEC

CABLE ROUTING
Clamp the front brake light switch lead at the
bends of handlebar.
Route the front brake hose and throttle cable
through the guide of the handlebar protector.
Route the throttle cable under the front brake
hose.
Route the clutch cable and parking brake cable
through the guide of the handlebar protector.
Route the clutch cable in front of the parking brake
cable.

2-26

SPEC

Clamp the clutch switch lead and handlebar switch
lead at the bends of handlebar.

CABLE ROUTING
Indicator light lead
Main switch lead
Coupler joint
Front brake light switch lead
Front brake hose 2
Oil cooler hose 1, 2
Exhaust pipe
Engine bracket
Rear brake light switch lead
Parking brake cable
Battery negative lead

A

Carburetor warmer lead
Air vent hose
Air filter case breather hose
Throttle cable
Front brake hose 1
Clutch cable
Main harness
Clamp
Frame complete
Rear brake reservoir hose
Carburetor overflow hose

SPEC

Neutral switch lead
Rear brake reservoir cover

A

F

H

H
F

A-A

H-H

2-27

CABLE ROUTING
To the front panel
To the front fender
To the handlebar
To the right headlight
Make sure to route the oil cooler hoses 1and 2
through the guide wire.
Install the front brake hose 2, making sure to face
the white paint mark forward.
Route the oil cooler hose 1 and 2 between the
exhaust pipe and the engine bracket.

A

SPEC

Route the battery negative lead behind the clutch
cable holder.
Route the air vent hose through the bracket.
Make sure that the white paint mark on the air filter
case breather hose
Make sure that the clip end is facing the left side of
the vehicle.
Route the throttle cable under the cross pipe and
left of the steering column as shown in the illustration.

A

F

H

H
F

A-A

H-H

2-28

CABLE ROUTING
Route the parking brake cable and the clutch cable
under the cross pipe and right of the steering column as shown in the illustration.
Route the rear brake light switch lead, neutral
switch lead, air vent hose, carburetor overflow
hose and parking brake cable through the bracket.
Route the rear brake light switch lead under the
bracket.
Route the rear brake light switch lead between the
bracket and rear brake reservoir tank.

A

SPEC

Route the neutral switch lead and rear brake light
switch lead as shown in the illustration.

A

F

H

H
F

A-A

H-H

2-29

CABLE ROUTING

SPEC

Rear brake reservoir
Rear brake light switch
Clip
Rear brake reservoir hose
Rear brake master cylinder
Parking brake cable
Rear brake hose
Rear brake caliper

D-D

C-C
E

C

D

E

C
D

2-30

CABLE ROUTING
Make sure that the end of the clip is facing downward.
Set the rear brake reservoir hose with the positioning yellow paint mark pointing down.
Install the rear brake hose in the direction shown in
the illustration.
Insert the rear brake hose until it contacts the projection.
Make sure that the end of the clip is facing outward.

D-D

SPEC

Install the rear brake reservoir hose, making sure
to face the white paint mark outward.
Insert the rear brake reservoir hose until it contacts
the projection.
When installing the rear brake hose, make sure
that the metal part on the rear brake Inlet hose is
touching the stopper of the rear caliper.

C-C
E

C

D

E

C
D

2-31

CABLE ROUTING
Clutch switch lead
Handlebar switch lead
Bolt
Main harness
Air vent hose
Clamp
Battery negative lead
AC magneto lead
Carburetor overflow hose
Starter motor lead

B-B

Neutral switch lead
Ignition coil spark plug lead
Ignition coil
Drain hose
Frame complete
Damper plate
Seat pad
Cover
Rear brake light switch lead
Carburetor warmer lead

SPEC

Air filter case breather hose
Air filter joint
Air filter case

G-G

B
D

G
M

B

I
I

G
E

N

E

N
L

C

D
M

C

L

D-D
I-I

N-N

L-L

C-C

E-E

2-32

M-M

CABLE ROUTING
To the front fender
Route the wire harness above the guide for the
damper plate.
Fix point for wire harness
Clamp near the hook of the air filter.
Clamp near the edge of the air filter case.
Route the drain hose in front of the left oil cooler
hose.
Clamp on top of the frame bracket.
To the left headlight
Route the clamp through the damper plate hole.

B-B

SPEC

Route the carburetor overflow hose as shown in
the illustration.
Fasten the clamp with the engine.
Route the leads on the upper inside of the cover.
Place the couplers on the inside of the cover.
Route the clamp through the frame bracket.

G-G

B
D

G
M

B

I
I

G
E

N

E

N
L

C

D
M

C

L

D-D
I-I

N-N

L-L

C-C

E-E

2-33

M-M

CABLE ROUTING
Indicator light
Coupler joint
Main switch lead
Front brake light switch lead
Throttle cable
Regulator
Flange bolt
Headlight lead
Indicator light lead
Clutch cable
Parking brake cable

SPEC

N

Rear brake reservoir
Rear brake light switch lead
Air vent hose
Battery negative lead
Carburetor warmer lead
Starter motor lead
Clutch switch lead
Handlebar switch lead
Main harness
Frame complete
Clamp

K-K

J-J

K
K
J
J

2-34

CABLE ROUTING

To the handlebar
Route the air vent hose through the bracket.
Route the battery negative lead behind the clutch
cable holder.
Fix point for wire harness
Insert the air vent hose into the fender.
Route the clutch switch lead and handlebar switch
lead on the box shaped part.
Connect the clutch switch lead and handlebar
switch lead on top of the front fender.
Route the wire harness from the front.

N

Install the indicator light as shown in the illustration.
Place the coupler joint above the front fender.
Route the front brake light switch lead and throttle
cable through the guide.
Connect the main switch lead on top of the front
fender.
Route both leads from the front.
Route the headlight lead under the frame.
To the front fender
To the front panel

SPEC

K-K

J-J

K
K
J
J

2-35

CABLE ROUTING

SPEC

N

Route the cables and leads through the guide of
the front fender.
Route the leads behind the clutch and parking
brake cable.

K-K

J-J

K
K
J
J

2-36

CABLE ROUTING
CDI unit
Band
Battery
Starter relay lead
Starter relay
Taillight lead
Battery negative lead
AC magneto coupler
Starter motor lead
Headlight relay
Neutral relay

SPEC

Damper
CDI unit lead
Relay lead

B

A

A

J

J

B
A-A

2-37

CABLE ROUTING
Route the starter relay lead under the starter
motor lead.
Clamp the taillight lead.
Do not clamp.
When clamping the wire harness, make sure that
the insulator lock is behind the clamp.
After connecting the battery negative lead, push
the sag in the box.

SPEC

After connecting the taillight lead and each electric
part, the length between the air filter and AC magneto coupler should be 185 mm (7.28 in) on
straight line.
There is no particular order in placing each lead.
Insert each relay all the way into the rib on the air
filter side.
Insert the starter relay all the way into the rib on
the air filter side.

B

A

A

J

J

B
A-A

2-38

INTRODUCTION/PERIODIC MAINTENANCE
CHART FOR THE EMISSION CONTROL SYSTEM
EBS00029

CHK
ADJ

PERIODIC CHECKS AND ADJUSTMENTS

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

PERIODIC MAINTENANCE CHART FOR THE EMISSION CONTROL
SYSTEM
NOTE:
• For ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals.
• For ATVs equipped with an odometer or an hour meter, follow the km (mi) or hours maintenance
intervals. However, keep in mind that if the ATV isn’t used for a long period of time, the month maintenance intervals should be followed.
• Items marked with an asterisk should be performed by a Yamaha dealer as they require special
tools, data and technical skills.
INITIAL

NO.

1

ITEM

CHECK OR MAINTENANCE
JOB

Whichever
comes
first

EVERY

month

1

3

6

6

12

km
(mi)

320
(200)

1300
(800)

2500
(1600)

2500
(1600)

5000
(3200)

hours

20

80

160

160

320

√

√

√

√

√

√

√

√

√

√

√

√

• Check fuel hoses for cracks or other damage, and replace
if necessary.

*

Fuel line
Spark plug

• Check condition and clean, regap, or replace if necessary.

√

3

*

Valves

• Check valve clearance and adjust if necessary.

√

4

*

Carburetor

• Check starter (choke) operation and correct if necessary.
• Check engine idling speed and adjust if necessary.

5

*

Crankcase breather
system

• Check breather hose for cracks or other damage, and
replace if necessary.

√

√

√

6

*

Exhaust system

• Check for leakage and replace gasket(s) if necessary.
• Check for looseness and tighten all screw clamps and
joints if necessary.

√

√

√

Spark arrester

• Clean.

√

√

√

2

7

3-1

√

√

CHK
ADJ

GENERAL MAINTENANCE AND LUBRICATION CHART

GENERAL MAINTENANCE AND LUBRICATION CHART
INITIAL

NO.

1
2

3

*

*

ITEM

CHECK OR MAINTENANCE
JOB

Whichever
comes
first

month

1

3

6

6

12

km
(mi)

320
(200)

1300
(800)

2500
(1600)

2500
(1600)

5000
(3200)

hours

20

80

160

160

320

Every 20 ~ 40 hours (more often in wet or dusty
areas)

Air filter element

• Clean and replace if necessary.

Clutch

• Check operation and adjust if necessary.

√

Front brake

• Check operation and correct if necessary.
• Check fluid level and ATV for fluid leakage, and correct if
necessary.

√

*

Rear brake

• Check operation and correct if necessary.
• Check fluid level and ATV for fluid leakage, and correct if
necessary.

√

*

Brake hoses

√

√

√

√

√

√

√

√

√

• Check for cracks or other damage, and replace if necessary.

√

√

√

√

Every 4 years

• Replace.
6

*

Parking brake

• Check operation and adjust if necessary.

√

√

√

√

7

*

Wheels

• Check runout and for damage, and replace if necessary.

√

√

√

√

8

*

Tires

• Check tread depth and for damage, and replace if necessary.
• Check air pressure and balance, and correct if necessary.

√

√

√

√

9

*

Wheel hub bearings

• Check for looseness or damage, and replace if necessary.

√

√

√

√

10

*

Swingarm pivots

• Check operation and for excessive play, and replace bearings if necessary.
• Lubricate with lithium-soap-based grease.

√

√

√

11

*

Upper and lower arm
pivots

• Lubricate with lithium-soap-based grease.

√

√

√

Drive chain

• Check chain slack and adjust if necessary.
• Check rear wheel alignment and correct if necessary.
• Clean and lubricate.

√

√

√

Drive chain rollers

• Check for wear and replace if necessary.

√

√

√

• Make sure that all nuts, bolts, and screws are properly
tightened.

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

12
13

*

14

*

Chassis fasteners

15

*

Shock absorber assem- • Check operation and correct if necessary.
blies
• Check for oil leakage and replace if necessary.

16

*

Rear suspension relay
arm and connecting
arm pivoting points

• Check operation and correct if necessary.
• Lubricate with lithium-soap-based grease.

17

*

Steering shaft

• Lubricate with lithium-soap-based grease.

Steering system

• Check operation and repair or replace if damaged.
• Check toe-in and adjust if necessary.

Engine mount

• Check for cracks or other damage, and replace if necessary.

Engine oil

• Change.
• Check ATV for oil leakage, and correct if necessary.

18
19

*
*

20

1
2

Whenever worn to the limit

• Replace brake pads.
5

√

√

Whenever worn to the limit

• Replace brake pads.

4

EVERY

21

Engine oil filter element • Clean or replace if necessary.

22

*

Moving parts and
cables

• Lubricate.

23

*

Throttle lever housing
and cable

• Check operation and correct if necessary.
• Check throttle cable free play and adjust if necessary.
• Lubricate throttle lever housing and cable.

24

*

Front and rear brake
switches

25

*

Lights and switches

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

√

• Check operation and correct if necessary.

√

√

√

√

√

• Check operation and correct if necessary.
• Adjust headlight beams.

√

√

√

√

√

3-2

3
4
5
6
7
8

GENERAL MAINTENANCE AND LUBRICATION CHART

CHK
ADJ

NOTE:
• The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
• Hydraulic brake service
• Regularly check and, if necessary, correct the brake fluid level.
• Every two years replace the internal components of the brake master cylinders and calipers, and
change the brake fluid.
• Replace the brake hoses every four years and if cracked or damaged.

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

3-3

SEAT, FENDERS AND FUEL TANK

CHK
ADJ

EBS00033

SEAT, FENDERS AND FUEL TANK
SEAT, FRONT FENDER AND HEADLIGHTS
7 Nm (0.7 m•kg, 5.2 ft•Ib)

7 Nm (0.7 m•kg, 5.2 ft•Ib)

Order

7 Nm (0.7 m•kg, 5.2 ft•Ib)

1

Job/Part
Removing the seat, front fender and
headlights
Seat

2
3
4
5
6
7
8
9

Indicator light coupler
Front panel
Plate
Main switch coupler
Front fender
Headlight coupler
Left headlight
Right headlight

Q’ty

7 Nm (0.7 m•kg, 5.2 ft•Ib)

Remarks
Remove the parts in the order listed.

1

NOTE:
Pull back the seat lock lever, than pull up
on the rear of the seat.

1
1
1
1
1
2
1
1

Disconnect.

Disconnect.
Disconnect.

For installation, reverse the removal
procedure.

3-4

CHK
ADJ

SEAT, FENDERS AND FUEL TANK
EBS00034

FOOT PROTECTORS AND ENGINE SKID PLATE

T.

R.

17 Nm (1.7 m•kg, 13 ft•Ib)

2
17 Nm (1.7 m•kg, 13 ft•Ib)

T.

R.

T.

R.

17 Nm (1.7 m•kg, 13 ft•Ib)

T.

R.

17 Nm (1.7 m•kg, 13 ft•Ib)

3

1
T.

R.

7 Nm (0.7 m•kg, 5.2 ft•Ib)

Order

1
2
3

Job/Part
Removing the foot protectors and
engine skid plate
Left foot protector
Right foot protector
Engine skid plate

Q’ty

Remarks
Remove the parts in the order listed.

1
1
1
For installation, reverse the removal
procedure.

3-5

SEAT, FENDERS AND FUEL TANK

CHK
ADJ

REAR FENDER AND AIR FILLTER CASE
7 Nm (0.7 m•kg, 5.2 ft•Ib)

7 Nm (0.7 m•kg, 5.2 ft•Ib)

7 Nm (0.7 m•kg, 5.2 ft•Ib)

7 Nm (0.7 m•kg, 5.2 ft•Ib)

Order

1
2
3

Job/Part
Removing the rear fender and air
fillter case
Seat/front fender

Q’ty

Remarks
Remove the parts in the order listed.
Refer to “SEAT, FENDERS AND FUEL
TANK”.

Rear fender
Battery cover
Battery lead

1
1
2

CAUTION:
First disconnect the negative lead,
then disconnect the positive lead.

4
5
6
7
8
9

Battery
Relay
CDI unit
Tail/brake light lead
Air filter case breather hose
Clamp

1
2
1
1
1
1

3-6

Disconnect.
Disconnect.
Loosen.

SEAT, FENDERS AND FUEL TANK

7 Nm (0.7 m•kg, 5.2 ft•Ib)

CHK
ADJ

7 Nm (0.7 m•kg, 5.2 ft•Ib)

7 Nm (0.7 m•kg, 5.2 ft•Ib)

7 Nm (0.7 m•kg, 5.2 ft•Ib)

Order
10

Job/Part
Air filter case

Q’ty
1

Remarks
For installation, reverse the removal
procedure.

3-7

CHK
ADJ

SEAT, FENDERS AND FUEL TANK
EBS00042

FUEL TANK
7 Nm (0.7 m•kg, 5.2 ft•Ib)
.

2
3
4
1

Order

Job/Part
Removing the fuel tank
Seat/front fender

Q’ty

1

Fuel hose (fuel cock side)

1

2

Fuel tank

1

3
4

Clamp
Fuel tank shield

1
1

Remarks
Remove the parts in the order listed.
Refer to “SEAT, FENDERS AND FUEL
TANK”.
NOTE:
Before disconnecting the fuel hose, turn
the fuel cock to “OFF”.
NOTE:
When installing the fuel tank, pass the fuel
tank breather hose through the hole in the
handlebar protector.

For installation, reverse the removal
procedure.

3-8

ADJUSTING THE VALVE CLEARANCE

CHK
ADJ

EAS00048

ENGINE
ADJUSTING THE VALVE CLEARANCE
The following procedure applies to all of the
valves.
NOTE:
• Valve clearance adjustment should be made
on a cold engine, at room temperature.
• When the valve clearance is to be measured
or adjusted, the piston must be at the Top
Dead Center (TDC) on the compression
stroke.
1. Remove:
• seat
• front fender
• fuel tank
Refer to “SEAT, FENDERS AND FUEL
TANK”.
2. Remove:
• spark plug cap
• spark plug
• cylinder head side cover 1
• cylinder head side cover 2

2
1

3. Remove:
• timing mark accessing screw
• crankshaft end accessing screw
4. Measure:
• valve clearance
Out of specification → Adjust.

1
2

Valve clearance (cold)
Intake valve
0.05 ~ 0.10 mm
(0.0020 ~ 0.0039 in)
Exhaust valve
0.10 ~ 0.15 mm
(0.0039 ~ 0.0059 in)

3-9

ADJUSTING THE VALVE CLEARANCE

CHK
ADJ

a. Turn the crankshaft counterclockwise.
b. When the piston is at the Top Dead Center
(TDC) on the compression stroke, align the
“I” mark
on the AC magneto rotor with
the stationary pointer
on the crankcase
cover.
NOTE:
Top dead center (TDC) is a point where the
mark on the AC magneto rotor and the pointer
on the crankcase cover match, plus at the
same time, the punch mark in the camshaft
sprocket and the pointer on the cylinder head
match.
c. Measure the valve clearance with a thickness gauge .
Out of specification → Adjust.

1

Thickness gauge
90890-03079
Narrow gauge set
YM-34483

5. Adjust:
• valve clearance

2

a. Loosen the locknut .
b. Insert a thickness gauge between the end
of the adjusting screw and the valve stem.
c. Turn the adjusting screw
until the specified valve clearance is obtained.

1

Tappet adjusting tool
90890-01311
Six piece tappet set
YM-A5970
• Hold the adjusting screw to prevent it from
moving and tighten the locknut to specifica14 Nm (1.4 m•kg, 10 ft•lb)
tion.

3-10

ADJUSTING THE VALVE CLEARANCE/
ADJUSTING THE ENGINE IDLING SPEED

CHK
ADJ

d. Measure the valve clearance again.
e. If the valve clearance is still out of specification, repeat all of the valve clearance
adjustment steps until the specified clearance is obtained.
6. Install:
• all removed parts
NOTE:
For installation, reverse the removal procedure.

EBS00051

ADJUSTING THE ENGINE IDLING SPEED
1. Start the engine and let it warm up for several minutes.
2. Attach:
• digital tachometer
(onto the ignition coil spark plug lead)
Digital tachometer
90890-06760, YU-39951-B
3. Measure:
• engine idling speed
Out of specification → Adjust.
Engine idling speed
1,500 ~ 1,600 r/min

3-11

ADJUSTING THE ENGINE IDLING SPEED/
ADJUSTING THE THROTTLE LEVER FREE PLAY

CHK
ADJ

4. Adjust:
• engine idling speed
a. Turn the throttle stop screw
in direction
or
until the specified idling speed is
obtained.
b

a

Direction
Direction

Idling speed becomes
higher.
Idling speed becomes
lower.

5. Remove:
• fuel tank
NOTE:
Slide the fuel tank.
6. Detach:
• digital tachometer
7. Adjust:
• throttle lever free play
Refer to “ADJUSTING THE THROTTLE
LEVER FREE PLAY”.
Throttle lever free play
2 ~ 4 mm (0.08 ~ 0.16 in)

EBS00052

ADJUSTING THE THROTTLE LEVER FREE
PLAY
NOTE:
Engine idling speed should be adjusted properly before adjusting the throttle lever free play.

1. Measure:
• throttle lever free play
Out of specification → Adjust.
Throttle lever free play
2 ~ 4 mm (0.08 ~ 0.16 in)

a

3-12

ADJUSTING THE THROTTLE LEVER FREE PLAY/
ADJUSTING THE SPEED LIMITER
2. Adjust:
• throttle lever free play

b

First step:
a. Slide back the rubber cover .
b. Loosen the locknut
on the carburetor
side.
c. Turn the adjusting nut
in direction
or
until the correct free play is obtained.

a
1
2

CHK
ADJ

3

Direction
Direction

Free play is increased.
Free play is decreased.

d. Tighten the locknut.
e. Slide the rubber cover to its original position.
NOTE:
If the free play cannot be adjusted here, adjust
it at the throttle lever side of the cable.

Second step:
f. Slide back the rubber cover .
g. Loosen the locknut .
h. Turn the adjusting bolt
in direction
or
until the correct free play is obtained.

d

4
c
6

Direction
Direction

5

Free play is increased.
Free play is decreased.

i. Tighten the locknut.
j. Slide the rubber cover to its original position.

WARNING
After adjusting the free play, turn the handlebar to the right and left to make sure
that the engine idling speed does not
increase.

EBS00053

ADJUSTING THE SPEED LIMITER
The speed limiter keeps the carburetor throttle
from becoming fully-opened even when the
throttle lever is applied to the maximum position. Screwing in the adjusting screw stops the
engine speed from increasing.

3-13

ADJUSTING THE SPEED LIMITER
1

a

CHK
ADJ

1. Measure:
• Speed limiter length
Out of specification → Adjust.

2

Speed limiter length
Less than 12 mm (0.47 in)

b

2. Adjust:
• speed limiter length

c

a. Loosen the locknut .
b. Turn the adjusting screw
in or out until
the specified speed limiter length is
obtained.
Direction
Direction

Speed limiter length is
decreased.
Speed limiter length is
increased.

c. Tighten the locknut.

WARNING
• Particularly for a beginner rider, the speed
limiter should be screwed in completely.
Screw it out little by little as their riding
technique improves. Never remove the
speed limiter for a beginning rider.
• For proper throttle lever operation do not
turn out the adjusting screw more than 12
mm (0.47 in). Also, always adjust the throttle lever free play to 2 ~ 4 mm (0.08 ~ 0.16
in).

3-14

CHECKING THE SPARK PLUG

CHK
ADJ

EBS00057

CHECKING THE SPARK PLUG
1. Disconnect:
• spark plug cap
2. Remove:
• spark plug
3. Check:
• spark plug type
Incorrect → Change.
Standard spark plug
NGK/DR7EA

4. Check:
• electrode
Wear/damage → Replace.
• insulator
Abnormal color → Replace.
Normal color is a medium-to-light tan color.
5. Clean:
• spark plug
(with a spark plug cleaner or wire brush)
6. Measure:
• spark plug gap
Use a wire gauge or thickness gauge.
Out of specification → Regap.
Spark plug gap
0.6 ~ 0.7 mm (0.024 ~ 0.028 in)
7. Install:
• spark plug
Spark plug
18 Nm (1.8 m•kg, 13 ft•lb)
NOTE:
Before installing a spark plug, clean the gasket
surface and plug surface.
8. Install:
• spark plug cap

3-15

CHECKING THE IGNITION TIMING

CHK
ADJ

EBS00058

CHECKING THE IGNITION TIMING
NOTE:
Engine idling speed and throttle cable free play
should be adjusted properly before checking
the ignition timing.
1. Attach:
• digital tachometer
Digital tachometer
90890-06760, YU-39951-B
• timing light
(onto the ignition coil spark plug lead)
Timing light
90890-03141
Inductive clamp timing light
YU-03141
2. Check:
• ignition timing

1

a. Warm up the engine and keep it at the
specified speed.
Engine speed
1,500 ~ 1,600 r/min

a

b. Remove the timing mark accessing screw
.
c. Visually check the stationary pointer
to
verify it is within the required firing range
indicated on the AC magneto rotor.
Incorrect firing range → Check the pickup
coil assembly.
d. Install the timing mark accessing screw.

b

3. Detach:
• timing light
• digital tachometer

3-16

MEASURING THE COMPRESSION PRESSURE

CHK
ADJ

MEASURING THE COMPRESSION
PRESSURE
The following procedure applies to the cylinder.
NOTE:
Insufficient compression pressure will result in
a loss of performance.
1. Measure:
• Valve clearance
Out of specification → Adjust.
Refer to “ADJUSTING THE VALVE CLEARANCE”
2. Start the engine, warm it up for several minutes, and then turn it off.
3. Disconnect:
• Spark plug cap
4. Remove:
• Spark plug
ECA13340

CAUTION:
Before removing the spark plug, use compressed air to blow away any dirt accumulated in the spark plug wells to prevent it
from falling into the cylinder.

5. Install:
• Compression gauge
• Extension

1

Compression gauge
90890-03081
Engine compression tester
YU-33223
Extension
90890-04082

2

3-17

MEASURING THE COMPRESSION PRESSURE

CHK
ADJ

6. Measure:
• Compression pressure
Out of specification → Refer to steps (c)
and (d).
Compression pressure (standard)
1,100 kPa/720 r/min
(11.2 kgf/cm2, 160 psi/720 r/min)
Compression pressure
(maximum)
1,300 kPa/720 r/min
(13.3 kgf/cm2, 189 psi /720 r/min)
Compression pressure (minimum)
900 kPa/720 r/min
(9.2 kgf/cm2, 131 psi /720 r/min)
a. Set the main switch to “ON”.
b. With the throttle wide open, crank the
engine until the reading on the compression gauge stabilizes.

WARNING
To prevent sparking, ground the spark plug
lead before cranking the engine.
c. If the compression pressure is above the
maximum specification, check the cylinder
head, valve surfaces and piston crown for
carbon deposits.
Carbon deposits → Eliminate.
d. If the compression pressure is below the
minimum specification, pour a teaspoonful
of engine oil into the spark plug bore and
measure again.
Refer to the following table.
Compression pressure
(with oil applied into the cylinder)
Reading
Diagnosis
Higher than without
Piston ring(s) wear or
oil
damage → Repair.
Piston, valves, cylinder head gasket or
Same as without oil
piston possibly
defective → Repair.

3-18

MEASURING THE COMPRESSION PRESSURE/
CHECKING THE ENGINE OIL LEVEL

CHK
ADJ

7. Install:
• Spark plug
Spark plug
18 Nm (1.8 m•kg, 13 ft•lb)
8. Connect:
• Spark plug cap

EBS01101

CHECKING THE ENGINE OIL LEVEL
1. Place the machine on a level surface.
2. Start the engine, warm it up several minutes, and then turn it off.

3. Check:
• engine oil level
Oil level should be between the minimum
level mark
and the maximum level mark
.
Low oil level → Add oil to the proper level.
NOTE:
• Wait a few minutes until the oil settles before
checking the oil level.
• Do not screw the dipstick
in when checking the oil level.

1

b

a

1

Recommended engine oil type
YAMALUBE 4, SAE 5W-30 or
SAE 10W-30 or SAE 20W-40
Recommended engine oil grade
API service SG type or higher
JASO standard MA

CAUTION:
• Do not add any chemical additives.
Engine oil also lubricates the clutch and
additives could cause clutch slippage.
• Do not allow foreign material to enter the
crankcase.

3-19

CHECKING THE ENGINE OIL LEVEL/
CHANGING THE ENGINE OIL

CHK
ADJ

4. Start the engine, warm it up for several minutes, and then turn it off.
5. Check:
• engine oil level
NOTE:
Before checking the engine oil level, wait a few
minutes until the oil has settled.

EBS00067

CHANGING THE ENGINE OIL
1. Place the machine on a level surface.
2. Start the engine, warm it up for several minutes, and then turn it off.
3. Place a container under the engine oil drain
bolt.

4. Remove:
• dipstick
• oil filter element drain bolt
1

2

5. Remove:
• engine oil drain bolt
(along with the washer)
6. Drain:
• engine oil
(completely from the crankcase)

1

7. If the oil filter element is also to be
replaced, perform the following procedure.
a. Remove the oil filter element cover
and
oil filter element .
b. Install new O-rings .
c. Install the new oil filter element and the oil
filter element cover.

1

10 Nm (1.0 m•kg, 7.4 ft•lb)

3-20

CHANGING THE ENGINE OIL

CHK
ADJ

8. Install:
• engine oil drain bolt gasket
• engine oil drain bolt

2

Engine oil drain bolt
20 Nm (2.0 m•kg, 15 ft•lb)
3

• oil filter element drain bolt
3

Oil filter element drain bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)
9. Fill:
• crankcase
(with the specified amount of the recommended engine oil)
Periodic oil replacement
1.25 L (1.10 Imp qt, 1.32 US qt)
With oil filter element replacement
1.35 L (1.19 Imp qt, 1.43 US qt)
Engine oil quantity
Total amount
1.60 L (1.41 Imp qt, 1.69 US qt)
10.Install:
• dipstick
11.Start the engine, warm it up for several minutes, and then turn it off.
12.Check:
• engine
(for engine oil leaks)
13.Check:
• engine oil level
Refer to “CHECKING THE ENGINE OIL
LEVEL”.

3-21

CHANGING THE ENGINE OIL/
ADJUSTING THE CLUTCH CABLE

CHK
ADJ

14.Check:
• engine oil pressure
a. Slightly loosen the oil gallery bolt .
b. Start the engine and keep it idling until
engine oil starts to seep from the oil gallery
bolt. If no engine oil comes out after one
minute, turn the engine off so that it will not
seize.
c. Check the engine oil passages, the oil filter
element and the oil pump for damage or
leakage. Refer to “OIL PUMP AND
BLANCER WEIGHT GEAR” in chapter 4.
d. Start the engine after solving the problem(s) and check the engine oil pressure
again.
e. Tighten the oil gallery bolt to specification.

1

7 Nm (0.7 m•kg, 5.2 ft•lb)

EBS00070

ADJUSTING THE CLUTCH CABLE
1. Check:
• clutch lever free play
Out of specification → Adjust.
Clutch lever free play
(at the clutch lever end)
5 ~ 10 mm (0.20 ~ 0.39 in)

2

2. Adjust:
• clutch release lever free play

3
b

a. Slide back the lever cover .
b. Loosen the locknut .
c. Turn the adjusting bolt
in direction
or
until the specified clutch cable free play
is obtained.

1

a

Direction
Direction

Clutch cable free play is
increased.
Clutch cable free play is
decreased.

d. Tighten the locknut.
e. Slide the rubber cover to its original position.

3-22

ADJUSTING THE CLUTCH CABLE/
CLEANING THE AIR FILTER ELEMENT

CHK
ADJ

EBS00073

CLEANING THE AIR FILTER ELEMENT
NOTE:
There is a check hose
at the bottom of the
air filter case. If dust and/or water collects in
this hose, clean the air filter element and air filter case.

1

1. Remove:
• seat
Refer to “SEAT, FENDERS AND FUEL
TANK”.

2. Remove:
• air filter case cover

1

2

3. Remove:
• wing bolt
• air filter element
• air filter element frame

1

CAUTION:
The engine should never be run without the
air filter; excessive piston and / or cylinder
wear may result.

3

4. Check:
• air filter element
Damage → Replace.

2

3-23

CLEANING THE AIR FILTER ELEMENT

CHK
ADJ

5. Clean:
• air filter element
a. Wash the element gently, but thoroughly in
solvent.

WARNING
Use a cleaning solvent which is designed
to clean parts only. Never use gasoline or
low flash point solvents as they may cause
a fire or explosion.
b. Squeeze the excess solvent out of the element and let it dry.

CAUTION:
Do not twist or wring out the element. This
could damage the foam material.
c. Apply Yamaha foam air filter oil or other
quality foam air filter oil (not spray type).
d. Squeeze out the excess oil.
NOTE:
The element should be wet but not dripping.
6. Install:
• air filter element frame

7. Apply:
• Lithium-soap-based grease
On the matching surface
on air filter element.
8. Install:
• air filter element
• wing bolt
NOTE:
Make sure its sealing surface matches the
sealing surface of the case so there is no air
leak.

a

9. Install:
• air filter case cover
10.Install:
• seat
Refer to “SEAT, FENDERS AND FUEL
TANK”.

3-24

CLEANING THE AIR FILTER ELEMENT/
CLEANING THE SPARK ARRESTER

CHK
ADJ

CLEANING THE SPARK ARRESTER
1. Clean:
• Spark arrester

1
2
1

WARNING
• Select a well-ventilated area free of combustible materials.
• Always let the exhaust system cool before
performing this operation.
• Do not start the engine when removing the
tailpipe from the muffler.
a. Remove the bolts .
b. Remove the tailpipe
from the muffler.
c. Tap the tailpipe lightly with a soft-face hammer or suitable tool, then use a wire brush
to remove any carbon deposits from the
spark arrester portion of the tailpipe and the
inner contact surfaces of the muffler.
d. Insert the tailpipe and gasket
into the
muffler.
e. Install the bolts and tighten it.

12

3-25

ADJUSTING THE FRONT BRAKE/ADJUSTING THE
BRAKE LEVER/ADJUSTING THE REAR BRAKE

CHK
ADJ

EBS00080

CHASSIS

a

ADJUSTING THE FRONT BRAKE
1. Measure:
• brake lever free play
Out of specification → Bleed the front brake
system.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM”.
Brake lever free play
(at the end of the brake lever)
0 mm (0 in)

1

ADJUSTING THE BRAKE LEVER
(For adjustment type model)
1. Adjust:
• brake lever position

2
b
a

a

a. While pushing the brake lever forward,
loosen the locknut .
b. While pushing the brake lever forward, turn
the adjusting bolt
in direction
or
until the brake lever is in the desired position.
c. Tighten the locknut.

CAUTION:
Be sure to tighten the locknut, as failing to
do so will cause poor brake performance.

EBS00085

ADJUSTING THE REAR BRAKE
1. Measure:
• rear brake pedal height
Out of specification → Adjust.
Rear brake pedal height
40.0 mm (1.57 in)

a

3-26

ADJUSTING THE REAR BRAKE/
ADJUSTING THE PARKING BRAKE

CHK
ADJ

2. Adjust:
• rear brake pedal height
a. Loosen the locknut .
b. Turn the adjusting bolt
until the brake
pedal height is within the specified limits.
c. Tighten the locknut.
NOTE:
When adjusting the brake pedal height make
sure the locknut-to-adjusting bolt clearance
does not exceed 2.2 ~ 3.2 mm (0.09 ~ 0.13 in).

a
2
1

WARNING
After this adjustment is performed, lift the
front and 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.

ADJUSTING THE PARKING BRAKE
1. Check:
• parking brake cable end length
Out of specification → Adjust.
Parking brake cable end length
64 ~ 68 mm (2.52 ~ 2.68 in)

3-27

ADJUSTING THE PARKING BRAKE/
CHECKING THE BRAKE FLUID LEVEL

CHK
ADJ

2. Adjust:
• parking brake cable end length
a. Loosen the locknut
and adjusting bolt
.
b. Slide back the rubber cover .
c. Loosen the locknut .
d. Turn the adjusting nut
in direction
or
until the specified brake cable end
length is obtained.
e. Tighten the locknut.
f. Slowly turn the adjusting bolt clockwise until
resistance is felt.
g. Turn it 1/8 counterclockwise.
h. Tighten the locknut .
16 Nm (1.6 m•kg, 11 ft•lb)

i. Slide the rubber cover to its original position.

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.

EBS00087

CHECKING THE BRAKE FLUID LEVEL
1. Place the machine on a level surface.
NOTE:
When checking the brake fluid level, make sure
that the top of the brake master cylinder reservoir or brake fluid reservoir is horizontal.

3-28

CHECKING THE BRAKE FLUID LEVEL/
CHECKING THE FRONT BRAKE PADS

CHK
ADJ

2. Check:
• brake fluid level
Below the minimum level mark
→ Add
the recommended brake fluid to the proper
level.
Recommended brake fluid
DOT 4
Front brake
Rear brake

WARNING
• Use only the designated brake fluid.
Other brake fluids may cause the rubber
seals to deteriorate, causing leakage and
poor brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake fluids may result in a harmful chemical reaction, leading to poor brake performance.
• When refilling, be careful that water does
not enter the brake fluid reservoir. Water
will significantly lower the boiling point of
the brake fluid and could cause vapor
lock.

CAUTION:
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
NOTE:
In order to ensure a correct reading of the
brake fluid level, make sure that the top of the
brake master cylinder reservoir or brake fluid
reservoir is horizontal.

EBS00088

CHECKING THE FRONT BRAKE PADS
1. Remove:
• front wheels
Refer to “FRONT AND REAR WHEELS” in
chapter 6.

3-29

CHECKING THE FRONT BRAKE PADS/
CHECKING THE REAR BRAKE PADS

CHK
ADJ

2. Check:
• brake pads
Wear indicator groove almost disappeared
→ Replace the brake pads as a set.
Refer to “FRONT AND REAR BRAKES” in
chapter 6.
Brake pad wear limit
1.5 mm (0.06 in)
3. Operate the brake lever.
4. Install:
• front wheels
Refer to “FRONT AND REAR WHEELS” in
chapter 6.

EBS00089

CHECKING THE REAR BRAKE PADS
1. Check:
• brake pads
Wear indicators almost touch the brake disc
→ Replace the brake pads as a set.
Refer to “FRONT AND REAR BRAKES” in
chapter 6.
Brake pad wear limit
1.0 mm (0.04 in)
2. Operate the brake pedal.

3-30

ADJUSTING THE REAR BRAKE LIGHT SWITCH/
CHECKING THE BRAKE HOSES

CHK
ADJ

ADJUSTING THE REAR BRAKE LIGHT
SWITCH
NOTE:
• The rear brake light switch is operated by
movement of the brake pedal.
• The rear brake light switch is properly
adjusted when the brake light comes on just
before the braking effect starts.
1. Check:
• rear brake light operation timing
Incorrect → Adjust.

2. Adjust:
• rear brake light operation timing
a. Hold the main body
of the rear brake
light switch so that it does not rotate and
turn the adjusting nut
in direction
or
until the rear brake light comes on at the
proper time.
Direction
Direction

Brake light comes on
sooner.
Brake light comes on
later.

EBS00092

CHECKING THE BRAKE HOSES
1. Remove:
• seat
• front fender
Refer to “SEAT, FENDERS AND FUEL
TANK”.

3-31

CHECKING THE BRAKE HOSES/
BLEEDING THE HYDRAULIC BRAKE SYSTEM

CHK
ADJ

2. Check:
• front brake hoses
• front brake pipe
• rear brake hose
Cracks/wear/damage → Replace.
3. Check:
• brake hose clamps
Loosen → Tighten.
4. Hold the machine in an upright position and
apply the front or rear brake.
5. Check:
• brake hoses
Apply the brake lever or brake pedal several
times.
Fluid leakage → Replace the hoses or pipe.
Refer to “FRONT AND REAR BRAKES” in
chapter 6.
6. Install:
• front fender
• seat
Refer to “SEAT, FENDERS AND FUEL
TANK”.

EBS00094

BLEEDING THE HYDRAULIC BRAKE
SYSTEM

WARNING
Bleed the hydraulic brake system whenever:
• the system is disassembled.
• a brake hose is loosened, disconnected or
replaced.
• the brake fluid level is very low.
• brake operation is faulty.

3-32

BLEEDING THE HYDRAULIC BRAKE SYSTEM

CHK
ADJ

NOTE:
• Be careful not to spill any brake fluid or allow
the brake master cylinder reservoir or brake
fluid reservoir to overflow.
• When bleeding the hydraulic brake system,
make sure there is always enough brake fluid
before applying the brake. Ignoring this precaution could allow air to enter the hydraulic
brake system, considerably lengthening the
bleeding procedure.
• If bleeding is difficult, it may be necessary to
let the brake fluid settle for a few hours.
Repeat the bleeding procedure when the tiny
bubbles in the hose have disappeared.

1. Bleed:
• hydraulic brake system
a. Fill the brake fluid reservoir to the proper
level with the recommended brake fluid.
b. Install the diaphragm (brake master cylinder reservoir or brake fluid reservoir).
c. Connect a clear plastic hose
tightly to
the bleed screw .
Front
Rear

d. Place the other end of the hose into a container.
e. Slowly apply the brake lever or brake pedal
several times.
f. Fully squeeze the brake lever or fully
depress the brake pedal and hold it in position.
g. Loosen the bleed screw.
NOTE:
Loosening the bleed screw will release the
pressure and cause the brake lever to contact
the grip or the brake pedal to fully extend.
h. Tighten the bleed screw and then release
the brake lever or brake pedal.
i. Repeat steps (e) to (h) until all of the air
bubbles have disappeared from the brake
fluid in the plastic hose.

3-33

BLEEDING THE HYDRAULIC BRAKE SYSTEM/
ADJUSTING THE SHIFT PEDAL

CHK
ADJ

j. Tighten the bleed screw to specification.
5 Nm (0.5 m•kg, 3.7 ft•lb)

k. Fill the brake fluid reservoir to the proper
level with the recommended brake fluid.
Refer to “CHECKING THE BRAKE FLUID
LEVEL”.

WARNING
After bleeding the hydraulic brake system,
check the brake operation.

EBS00098

ADJUSTING THE SHIFT PEDAL
1. Measure:
• shift pedal height
Out of specification → Adjust.
Shift pedal height
15.2 mm (0.60 in)

2. Adjust:
• shift pedal position
a. Remove the drive sprocket cover .
Refer to “REAR SHOCK ABSORBER,
SWINGARM AND DRIVE CHAIN” in chapter 6.
b. Remove the bolt .
c. Remove the shift pedal .
d. Install the shift pedal at the correct height.
e. Tighten the bolt to specification.
10 Nm (1.0 m•kg, 7.4 ft•lb)

3-34

ADJUSTING THE DRIVE CHAIN SLACK

CHK
ADJ

ADJUSTING THE DRIVE CHAIN SLACK
NOTE:
• Measure the drive chain slack halfway
between the drive axle and the rear axle.
• When checking and adjusting the drive chain
slack, there should be no weight on the vehicle and all tires must be touching the ground.

CAUTION:
A drive chain that is too tight will overload
the engine and other vital parts, and one
that is too loose can skip and damage the
swingarm or cause an accident. Therefore,
keep the drive chain slack within the specified limits.

1. Measure:
• drive chain slack
Out of specification → Adjust.
Drive chain slack
45 ~ 55 mm (1.77 ~ 2.17 in)

2. Adjust:
• drive chain slack
NOTE:
The drive chain slack is adjusted by the rotation of the rear axle hub.
a. Loosen the rear axle pinch bolts .
b. Insert a rod of a diameter of 8 mm (0.31 in)
and length of 10 cm (4 in)
in the hole
of rear axle hub .
c. Shift the transmission into the neutral position.
d. To loosen the drive chain, push the vehicle
forward and to tighten the drive chain, pull
the vehicle backward.

3-35

ADJUSTING THE DRIVE CHAIN SLACK/
CHECKING THE STEERING SYSTEM

CHK
ADJ

CAUTION:
Excessive chain slack will overload the
engine and other vital parts; keep the slack
within the specified limits.

1 2
5 6

e. If the chain slack cannot be adjusted,
replace the sprockets and drive chain as a
set.
f. Tighten the rear axle pinch bolts .

3 4
7 8

21 Nm (2.1 m•kg, 15 ft•lb)

NOTE:
• Tighten the rear axle pinch bolts
in the
proper sequence as shown.
• The chain should be cleaned and lubricated
after every use of the vehicle.

EBS00106

CHECKING THE STEERING SYSTEM
1. Place the machine on a level surface.
2. Check:
• steering assembly bushings
Move the handlebar up and down, and/or
back and forth.
Excessive play → Replace the steering
stem bushings.

3. Check:
• tie-rod ends
Turn the handlebar to the left and right until
it stops completely, and then move the handlebar slightly in the opposite direction.
Tie-rod end(s)
have vertical play →
Replace the tie-rod end(s).

4. Raise the front end of the machine so that
there is no weight on the front wheels.
5. Check:
• ball joints and/or wheel bearings
Move the wheels laterally back and forth.
Excessive free play → Replace the front
arms (upper and lower) and/or wheel bearings.

3-36

ADJUSTING THE TOE-IN

CHK
ADJ

EBS00108

ADJUSTING THE TOE-IN
1. Place the machine on a level surface.
2. Measure:
• toe-in
Out of specification → Adjust.
Toe-in
9 ~ 19 mm (0.35 ~ 0.75 in)

NOTE:
Before measuring the toe-in, make sure that
the tire pressure is correct.
a.
b.
c.
d.

Mark both front tire tread centers.
Face the handlebar straight ahead.
Measure the width
between the marks.
Rotate the front tires 180° until the marks
are exactly opposite one another.
e. Measure the width
between the marks.
f. Calculate the toe-in using the formula given
below.
Toe-in =

–

g. If the toe-in is incorrect, adjust it.
Forward

3. Adjust:
• toe-in

WARNING
• Be sure that both tie-rods are turned the
same amount. If not, the machine will drift
right or left even though the handlebar is
positioned straight. This may lead to mishandling and an accident.
• After setting the toe-in to specification,
run the machine slowly for some distance
with both hands lightly holding the handlebar and check that the handlebar
responds correctly. If not, turn either the
right or left tie-rod within the toe-in specification.

3-37

ADJUSTING THE TOE-IN/CHECKING THE FRONT AND
REAR SHOCK ABSORBERS

CHK
ADJ

a. Mark both tie-rods ends.
This reference point will be needed during
adjustment.
b. Loosen the locknuts (tie-rod end)
of both
tie-rods.
c. The same number of turns should be given
to both the right and left tie-rods
until the
specified toe-in is obtained. This is to keep
the length of the rods the same.
d. Tighten the rod end locknuts of both tie15 Nm (1.5 m•kg, 11 ft•lb)
rods.
NOTE:
Adjust the rod ends so that A and B are equal.

EBS00109

CHECKING THE FRONT AND REAR SHOCK
ABSORBERS
1. Place the machine on a level surface.
2. Check:
• damper rod
Bends/damage → Replace the front/rear
shock absorber assembly.
• oil leakage
Excessive oil leakage → Replace the front/
rear shock absorber assembly.
• cylinder
Damage → the front/rear shock absorber
assembly.
• spring
Fatigue → the front/rear shock absorber
assembly.
Refer to “FRONT ARMS AND FRONT
SHOCK ABSORBER ASSEMBLIES” and
“REAR SHOCK ABSORBER, SWINGARM
AND DRIVE CHAIN” in chapter 6.
3. Check:
• operation
Pump the shock absorbers up and down for
several times.
Unsmooth operation → Replace the front/
rear shock absorber assembly.
Refer to “ADJUSTING THE FRONT
SHOCK ABSORBERS” and “ADJUSTING
THE REAR SHOCK ABSORBER”.
Front shock absorber
Rear shock absorber

3-38

ADJUSTING THE FRONT SHOCK ABSORBERS

CHK
ADJ

EBS00111

ADJUSTING THE FRONT SHOCK
ABSORBERS

WARNING
Always adjust the spring preload of both
front shock absorbers to the same setting.
Uneven adjustment can result in poor handling and loss of stability.

1. Adjust:
• spring preload
a. Turn the adjusting ring
in direction
with the spanner wrench .
1

2 3
4 5

Direction

Direction

Spring preload is
increased (suspension is
harder).
Spring preload is
decreased (suspension is
softer).

Standard position: 2
Minimum position: 1
Maximum position: 5
Ring nut wrench
90890-01268
Spanner wrench
YU-01268

3-39

or

ADJUSTING THE REAR SHOCK ABSORBER

CHK
ADJ

EBS00111

ADJUSTING THE REAR SHOCK
ABSORBER
1. Adjust:
• spring preload
a. Elevate the rear wheels by placing a suitable stand under the frame.
b. Loosen the locknut .
c. Turn the adjusting nut
in direction
or
.
Direction

Direction

Spring preload is
increased (suspension is
harder).
Spring preload is
decreased (suspension is
softer).

Adjusting length
Standard: 230 mm (9.06 in)
Minimum: 222 mm (8.74 in)
Maximum: 234 mm (9.21 in)
NOTE:
• Be sure to remove all dirt and mud from
around the locknut and adjusting nut before
adjustment.
• The length of the spring (installed) changes
1.0 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.
42 Nm (4.2 m•kg, 31 ft•lb)

NOTE:
Always tighten the locknut against the adjusting nut, then torque it to specification.

3-40

CHECKING THE TIRES

CHK
ADJ

EBS00114

CHECKING THE TIRES

WARNING
This model is equipped with low pressure
tires. It is important that they be inflated
correctly and maintained at the proper
pressures.
• TIRE CHARACTERISTICS
1) Tire characteristics influence the handling of ATVs. The tires listed below
have been approved by Yamaha Motor
Co., Ltd. for this model. If other tire combinations are used, they can adversely
affect your machine’s handling characteristics and are therefore not recommended.
Manufacturer

Size

Type

Front

DUNLOP

AT20 ×
7-10

KT201

Rear

DUNLOP

AT19 ×
KT205A
10-9

• TIRE PRESSURE
1) Recommended tire pressure
Front 27.5 kPa (0.28 kg/cm2, 4.0 psi)
Rear 27.5 kPa (0.28 kg/cm2, 4.0 psi)
2) Tire pressure below the minimum specification could cause the tire to dislodge
from the rim under severe riding conditions.
The following are minimums:
Front 24.5 kPa (0.25 kg / cm2, 3.6 psi)
Rear 24.5 kPa (0.25 kg / cm2, 3.6 psi)
3) Use no more than
Front 250 kPa (2.6 kg / cm2, 36 psi)
Rear 250 kPa (2.6 kg / cm2, 36 psi)
when seating the tire beads. Higher
pressures may cause the tire to burst.
Inflate the tires slowly and carefully.
Fast inflation could cause the tire to
burst.
• MAXIMUM LOADING LIMIT
1) Vehicle load limits: 100 kg (220 lb)
*Total weight of the cargo, rider, and
accessories.
Be extra careful of the machine balance
and stability when towing a trailer.

3-41

CHECKING THE TIRES

CHK
ADJ

1. Measure:
• tire pressure
Out of specification → Adjust.
NOTE:
• The low-pressure tire gauge
is included as
standard equipment.
• If dust or the like is stuck to this gauge, it will
not provide the correct readings. Therefore,
take two measurements of the tire’s pressure
and use the second reading.
Cold tire
pressure
Standard
Minimum
Maximum

Front/Rear
27.5 kPa
(0.28 kg/cm2, 4.0 psi)
24.5 kPa
(0.25 kg/cm2, 3.6 psi)
30.5 kPa
(0.31 kg/cm2, 4.4 psi)

WARNING
Uneven or improper tire pressure may
adversely affect the handling of this
machine and may cause loss of control.
• Maintain proper tire pressures.
• Set tire pressures when the tires are cold.
• Tire pressures must be equal in both front
tires and equal in both rear tires.

2. Check:
• tire surfaces
Wear/damage → Replace.
Tire wear limit
Front and rear: 3.0 mm (0.12 in)

WARNING
It is dangerous to ride with a worn-out tire.
When tire wear is out of specification,
replace the tire immediately.

3-42

CHECKING THE WHEELS/CHECKING AND
LUBRICATING THE CABLES

CHK
ADJ

EBS00116

CHECKING THE WHEELS
1. Check:
• wheel
Damage/bends → Replace.
NOTE:
Always balance the wheel when a tire or wheel
has been changed or replaced.

WARNING
• Never attempt even small repairs to the
wheel.
• Ride conservatively after installing a tire
to allow it to seat itself properly on the rim.

EBS00117

CHECKING AND LUBRICATING THE
CABLES

WARNING
A damaged cable sheath may cause corrosion and interfere with the cable movement.
An unsafe condition may result so replace
a damaged cable as soon as possible.
1. Check:
• cable sheath
Damage → Replace.
2. Check:
• cable operation
Unsmooth operation
replace.

→

Lubricate

or

Recommended lubricant
Yamaha chain and cable lube or
engine oil
NOTE:
Hold the cable end up and apply several drops
of lubricant to the cable.
3. Apply:
• Lithium-soap-based grease
(onto end of the cable)

3-43

LUBRICATING THE LEVERS AND PEDALS

CHK
ADJ

EBS00118

LUBRICATING THE LEVERS AND PEDALS
Lubricate the pivoting point and metal-to-metal
moving parts of the levers and pedal.
Recommended lubricants
Brake lever
Silicone grease
Clutch lever and brake pedal
Lithium-soap-based grease

3-44

CHECKING AND CHARGING THE BATTERY

CHK
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 handling 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 followed 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 different from those of conventional batteries. The MF battery should be charged as
explained in the charging method illustrations. If the battery is overcharged, the
electrolyte level will drop considerably.
Therefore, take special care when charging the battery.

3-45

CHECKING AND CHARGING THE BATTERY

CHK
ADJ

NOTE:
Since MF batteries are sealed, it is not possible to check the charge state of the battery by
measuring the specific gravity of the electrolyte. Therefore, the charge of the battery has to
be checked by measuring the voltage at the
battery terminals.
1. Remove:
• seat
• battery cover
Refer to “SEAT, FENDERS AND FUEL
TANK”.

2. Disconnect:
• battery leads
(from the battery terminals)

CAUTION:
First, disconnect the negative battery lead
, and then the positive battery lead .
3. Remove:
• battery
4. Check:
• battery charge
a. Connect a pocket tester to the battery terminals.

Open-circuit voltage (V)

Positive tester probe →
positive battery terminal
Negative tester probe →
negative battery terminal
NOTE:
• The charge state of an MF battery can be
checked by measuring its open-circuit voltage
(i.e., the voltage when the positive terminal is
disconnected).
• No charging is necessary when the open-circuit voltage equals or exceeds 12.8 V.

Relationship between the open-circuit voltage
and the charging time at 20 °C (68 °F)

Charging time (hours)
These values vary with the temperature, the condition of
the battery plates, and the electrolyte level.

b. Check the charge of the battery, as shown
in the charts and the following example.

3-46

CHECKING AND CHARGING THE BATTERY

CHK
ADJ

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

14
13
12
11
10

5. Charge:
• battery
(refer to the appropriate charging method
illustration)

Ambient temperature
20°C (68°F)

WARNING
Do not quick charge a battery.
0

10

20

30

40

50

60 Time (minutes)

Check the open-circuit
voltage.

Open-circuit voltage (V)

Open-circuit voltage (V)

Charging
18
17
16
15

14
13

CAUTION:
• Never remove the MF battery sealing caps.
• 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
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 battery 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 terminal
and that they are not shorted. A corroded
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!

Ambient
temperature
20°C (68°F)

12
11
10

100
75
50 30 25 20
0
Charging condition of the battery (%)

3-47

CHECKING AND CHARGING THE BATTERY

CHK
ADJ

• As shown in the following illustration, the
open-circuit voltage of an MF battery stabilizes about 30 minutes after charging
has been completed. Therefore, wait 30
minutes after charging is completed
before measuring the open-circuit voltage.

3-48

CHK
ADJ

CHECKING AND CHARGING THE BATTERY
Charging method using a variable-current (voltage) charger
Charger
Ammeter

Measure the open-circuit
voltage prior to charging.

Connect a charger and
ammeter to the battery
and start charging.

YES

Is the amperage higher
than the standard charging amperage written on
the battery?

Leave the battery unused for
more than 30 minutes before
measuring its open-circuit voltage.

Set the charging voltage to 16 ~
17 V. (If the charging voltage is
lower, charging will be insufficient,
if it is higher, the battery will be
over-charged.)

NO

Adjust the charging voltage
to 20 ~ 25 V.

Adjust the voltage to obtain
the standard charging amperage.

YES

Monitor the amperage for 3 ~ 5
minutes. Is the standard charging amperage exceeded?
NO

If the amperage does not
exceed the standard charging amperage after 5 minutes, replace the battery.

Set the timer to the charging
time determined by the opencircuit voltage.
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.

3-49

CHECKING AND CHARGING THE BATTERY

CHK
ADJ

Charging method using a constant voltage charger

Measure the open-circuit
voltage prior to charging.

Leave the battery unused for 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
than the standard charging amperage written on
the battery?

Charge the battery until the charging
voltage reaches 15 V.

This type of battery charger cannot
charge an MF battery. A variablevoltage charger is recommended.

Set the charging time to a maximum of 20 hours.

Charger

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.

Ammeter
Voltmeter

Constant amperage chargers are not
suitable for charging MF batteries.

3-50

CHECKING AND CHARGING THE BATTERY

CHK
ADJ

6. Install:
• battery

7. Connect:
• battery leads
(to the battery terminals)

CAUTION:
First, connect the positive battery lead
and then the negative battery lead .

,

8. Check:
• battery terminals
Dirt → Clean with a wire brush.
Loose connection → Connect properly.
9. Lubricate:
• battery terminals
Recommended lubricant
Dielectric grease
10.Install:
• battery cover
• seat
Refer to “SEAT, FENDERS AND FUEL
TANK”.

3-51

CHECKING THE FUSES

CHK
ADJ

EBS00121

CHECKING THE FUSES
The following procedure applies to all of the
fuses.

CAUTION:
To avoid a short circuit, always set the main
switch to “OFF” when checking or replacing a fuse.
1. Remove:
• seat
• battery cover
Refer to “SEAT, FENDERS AND FUEL
TANK”.

2. Check:
• fuse
a. Connect the pocket tester to the fuse and
check the continuity.
NOTE:
Set the pocket tester selector to “Ω × 1”.
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
b. If the pocket tester indicates “•”, replace the
fuse.
3. Replace:
• blown fuse
a. Set the main switch to “OFF”.
b. Install a new fuse of the correct amperage.
c. Set on the switches to verify if the electrical
circuit is operational.
d. If the fuse immediately blows again, check
the electrical circuit.

3-52

CHK
ADJ

CHECKING THE FUSES/
ADJUSTING THE HEADLIGHT BEAM

Items

Amperage
rating

Q’ty

Main

15 A

1

Reserve

15 A

1

WARNING
Never use a fuse with an amperage rating
other than that specified. Improvising or
using a fuse with the wrong amperage rating may cause extensive damage to the
electrical system, cause the lighting and
ignition systems to malfunction and could
possibly cause a fire.
4. Install:
• battery cover
• seat
Refer to “SEAT, FENDERS AND FUEL
TANK”.

EBS00122

ADJUSTING THE HEADLIGHT BEAM
1. Adjust:
• headlight beam (vertically)
a. Turn the adjusting bolt
.
Direction
Direction

3-53

in direction

Headlight beam is
raised.
Headlight beam is
lowered.

or

REPLACING A HEADLIGHT BULB

CHK
ADJ

EBS00124

REPLACING A HEADLIGHT BULB
1. Remove:
• headlight
Refer to “SEAT, FENDERS AND FUEL
TANK”.

2. Disconnect:
• headlight lead coupler
3. Remove:
• headlight bulb holder cover

4. Remove:
• bulb holder
• 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.
5. Install:
• bulb
Secure the new bulb with the headlight unit.

CAUTION:
Avoid touching the glass part of the bulb.
Keep it free from oil; otherwise, the transparency 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 lacquer thinner.

3-54

REPLACING A HEADLIGHT BULB

CHK
ADJ

6. Install:
• bulb holder
• headlight bulb holder cover
NOTE:
After installing the bulb holder cover, make
sure that the “TOP” mark
is in the position
shown.
7. Connect:
• headlight lead coupler
8. Install:
• headlight
Refer to “SEAT, FENDERS AND FUEL
TANK”.

3-55

ENGINE REMOVAL

ENG

ENGINE
ENGINE REMOVAL
MUFFLER AND EXHAUST PIPE

1

34 Nm (3.4 m•kg, 25 ft•lb)

2
3
4
20 Nm (2.0 m•kg, 15 ft•lb)

5

8 Nm (0.8 m•kg, 5.9 ft•lb)

18 Nm (1.8 m•kg, 13 ft•lb)

Order

1
2
3
4
5
6

Job/Parts to remove
Removing the muffler and exhaust
pipe
Seat/front panel/fender

Q’ty

Clamp
Muffler
Gasket
Exhaust pipe
EXhaust pipe protector
Gasket

1
1
1
1
1
1

Remarks
Remove the parts in the order listed.
Refer to “SEAT, FENDERS AND FUEL
TANK” in chapter 3.
Loosen

7
8

For installation, reverse the removal
procedure.

4-1

6

ENGINE REMOVAL

ENG

INSTALLING THE EXHAUST PIPE AND
MUFFLER
1. Install:
• gasket
(to muffler)
Installed depth of gasket
3.5 mm (0.14 in)

2. Install:
• exhaust pipe protector
3. Tighten:
• exhaust pipe protector screws
Screw
8 Nm (0.8 m•kg, 5.9 ft•lb)
LOCTITE®

4. Install:
• gasket
• exhaust pipe
5. Tighten:
• nuts (exhaust pipe)
Exhaust pipe nut
18 Nm (1.8 m•kg, 13 ft•lb)

6. Install:
• clamp
NOTE:
Slide the clamp onto the end of the muffler and
insert the projection
of the clamp into a slot
in the muffler. Tighten the clamp after
installing the muffler.

4-2

ENGINE REMOVAL

ENG

LEADS, CABLES AND HOSES

7
6

9
8

1

2

3

10 Nm (1.0 m•kg, 7.4 ft•lb)

5

Order

1
2
3
4
5
6
7
8

Job/Parts to remove
Removing the leads, cables and
hoses
Engine oil
Oil cooler hose 1, 2
Carburetor
Drive sprocket/drive chain

Q’ty

4

Remarks
Remove the parts in the order listed.
Drain.
Refer to “CLUTCH”.
Refer to “CARBURETOR” in chapter 5.
Refer to “REAR SHOCK ABSORBER,
SWINGARM AND DRIVE CHAIN” in
chapter 6.

Ignition coil spark plug lead
Air filter case breather hose
Starter motor lead
Battery negative lead
Clutch cable
Plastic band
Parking brake cable
AC magneto coupler

1
1
1
1
1
1
1
2

4-3

Disconnect.
Disconnect.
Disconnect.
Disconnect.

ENGINE REMOVAL

ENG

7
6

9
8

1

2

3

10 Nm (1.0 m•kg, 7.4 ft•lb)

5

Order
9

Job/Parts to remove
Neutral switch connector

4

Q’ty
Remarks
1 Disconnect.
For installation, reverse the removal
procedure.

4-4

ENGINE REMOVAL

ENG

ENGINE MOUNTING BOLTS
33 Nm (3.3 m•kg, 24 ft•lb)
40 Nm (4.0 m•kg, 30 ft•lb)
66 Nm (6.6 m•kg, 49 ft•lb)

33 Nm (3.3 m•kg, 24 ft•lb)
66 Nm (6.6 m•kg, 49 ft•lb)
40 Nm (4.0 m•kg, 30 ft•lb)
33 Nm (3.3 m•kg, 24 ft•lb)

Order

1
2
3
4
5
6
7
8

Job/Parts to remove
Removing the engine mounting
bolts
Crankcase bolt
Engine mounting bolt (front)
Engine bracket (left and right)
Engine mounting bolt (upper)
Engine bracket (upper)
Engine mounting bolt (rear upper)
Engine mounting bolt (rear lower)
Engine assembly

Q’ty

Remarks
Remove the parts in the order listed.

1
1
2
1
1
1
1
1
For installation, reverse the removal
procedure.

4-5

ENGINE REMOVAL

ENG

INSTALLING THE ENGINE
1. Install:
• Engine mounting bolt (rear lower side)
• Engine mounting bolt (rear upper side)
• Engine bracket bolts (upper side)
• Engine mounting bolt (upper side)
• Engine brackets (front side)
• Engine mounting bolt (front side)
NOTE:
• The direction of the bolt insertion is made
from the right side of the body.
• Do not fully tighten the bolts and nuts.
2. Install:
• Crankcase bolt
3. Tighten:
• Engine bracket bolts (upper side)
• Engine mounting nut (rear lower side)
• Engine mounting nut (rear upper side)
• Engine mounting nut (upper side)
• Engine mounting nut (front side)
• Engine bracket bolts (front side)
• Crankcase nut

40 Nm (4.0 m

4-6

Engine bracket bolt (upper side)
33 Nm (3.3 m•kg, 24 ft•lb)
Engine mounting nut (rear lower
side)
66 Nm (6.6 m•kg, 49 ft•lb)
Engine mounting nut (rear upper
side)
66 Nm (6.6 m•kg, 49 ft•lb)
Engine mounting nut (upper side)
66 Nm (6.6 m•kg, 49 ft•lb)
Engine mounting nut (front lower
side)
40 Nm (4.0 m•kg, 30 ft•lb)
Engine bracket bolt (M8)
33 Nm (3.3 m•kg, 24 ft•lb)
Crankcase nut
40 Nm (4.0 m•kg, 30 ft•lb)

CYLINDER HEAD

ENG

CYLINDER HEAD

10 Nm (1.0 m•kg, 7.4 ft•lb)

60 Nm (6.0 m•kg, 44 ft•lb)
10 Nm (1.0 m•kg, 7.4 ft•lb)

18 Nm (1.8 m•kg, 13 ft•lb)
24 Nm (2.4 m•kg, 18 ft•lb)
18 Nm (1.8 m•kg, 13 ft•lb)
10 Nm (1.0 m•kg, 7.4 ft•lb)

20 Nm (2.0 m•kg, 15 ft•lb)

Order

1
2
3
4
5
6
7
8

Job/Parts to remove
Removing the cylinder head
Seat/front fender/fuel tank/fuel tank
shield
Muffler and exhaust pipe
Carburetor
Ignition coil spark plug lead
Engine bracket (upper side)
Spark plug
Cylinder head cover 1/O-ring
Cylinder head cover 2/O-ring
Cylinder head cover 3/O-ring
Breather pipe 1/Gasket
Crankshaft end accessing screw/
O-ring
Timing mark accessing screw/O-ring
Camshaft sprocket bolt

Q’ty

Remarks
Refer to “SEAT, FENDERS AND FUEL
TANK” in chapter 3.
Refer to “MUFFLER AND EXHAUST
PIPE”.
Refer to “CARBURETOR” in chapter 5.
Refer to “LEADS, CABLES AND HOSES”.
Refer to “ENGINE MOUNTING BOLTS”.

1
1/1
1/1
1/1
1/1
1/1
1/1
1 Loosen.

4-7

CYLINDER HEAD

ENG

10 Nm (1.0 m•kg, 7.4 ft•lb)

60 Nm (6.0 m•kg, 44 ft•lb)
10 Nm (1.0 m•kg, 7.4 ft•lb)

18 Nm (1.8 m•kg, 13 ft•lb)
24 Nm (2.4 m•kg, 18 ft•lb)
18 Nm (1.8 m•kg, 13 ft•lb)
10 Nm (1.0 m•kg, 7.4 ft•lb)

20 Nm (2.0 m•kg, 15 ft•lb)

Order
9
10
11
12
13
14
15
16

Job/Parts to remove
Cap bolt
Timing chain tensioner/gasket
Breather pipe 2
Camshaft sprocket/dowel pin
Cylinder head
Timing chain guide
Dowel pin
Cylinder head gasket

Q’ty
Remarks
1 Loosen.
1/1
1
1/1
1
1
2
1
For installation, reverse the removal
procedure.

4-8

CYLINDER HEAD

ENG

REMOVING THE CYLINDER HEAD
1. Align:
• “I” mark
on the Pickup coil rotor
(with the stationary pointer
on the crankcase cover)

a. Turn the Pickup coil rotor counterclockwise.
b. When the piston is at TDC on the compression stroke, align the “I” mark
on the
camshaft sprocket with the mark
on the
cylinder head.

2. Loosen:
• Camshaft sprocket bolt

3. Remove:
• Timing chain tensioner cap
• Timing chain tensioner
(along with the gasket)
• Camshaft sprocket bolt
• Breather plate 2
• Camshaft sprocket
• Timing chain
NOTE:
To prevent the timing chain from falling into the
crankcase, fasten it with a wire.
4. Remove:
• Cylinder head

4-9

CYLINDER HEAD

ENG

CHECKING THE CYLINDER HEAD
1. Eliminate:
• Combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid damaging or scratching:
• Spark plug bore threads
• Valve seats
2. Check:
• Cylinder head
Damage/scratches → Replace.

3. Measure:
• Cylinder head warpage
Out of specification → Resurface the cylinder head.
Warpage limit
0.05 mm (0.0020 in)
a. Place a straightedge
and a thickness
gauge
across the cylinder head.
b. Measure the warpage.
c. If the limit is exceeded, resurface the cylinder head as follows.
d. Place a 400–600 grit wet sandpaper on the
surface plate and resurface the cylinder
head using a figure-eight sanding pattern.
NOTE:
To ensure an even surface, rotate the cylinder
head several times.

4-10

CYLINDER HEAD

ENG

CHECKING THE TIMING CHAIN GUIDES
The following procedure applies to the camshaft sprockets and timing chain guides.
1. Check:
• Timing chain
Damage/stiffness → Replace the timing
chain and camshaft sprocket and crankshaft sprocket as a set.

2. Check:
• Camshaft sprocket
More than 1/4 tooth wear
→ Replace
the timing chain and camshaft sprocket and
crankshaft sprocket as a set.
1/4 tooth
Correct
Timing chain
Camshaft sprocket

3. Check:
• Timing chain guide (exhaust side)

CHECKING THE TIMING CHAIN
TENSIONERS
1. Check:
• Timing chain tensioner
Cracks/damage → Replace.
2. Check:
• One-way cam operation
Rough movement → Replace the timing
chain tensioner housing.
a. Lightly press the timing chain tensioner rod
into the timing chain tensioner housing by
hand.
NOTE:
While pressing the timing chain tensioner rod,
wind it clockwise with a thin screwdriver
until it stops.

4-11

CYLINDER HEAD

ENG

b. Remove the screwdriver and slowly release
the timing chain tensioner rod.
c. Make sure that the timing chain tensioner
rod comes out of the timing chain tensioner
housing smoothly. If there is rough movement, replace the timing chain tensioner.
3. Check:
• Cap bolt
• Copper washer
• Spring
• One-way cam
• Timing chain tensioner rod
Damage/wear → Replace the defective
part(s).

INSTALLING THE CYLINDER HEAD
1. Install:
• Cylinder head gasket
• Dowel pins
2. Install:
• Cylinder head
• Copper washers
• Cylinder head bolts

3. Tighten:
• Cylinder head bolts
Cylinder head bolt 226 mm (8.90 in)
24 Nm (2.4 m•kg, 18 ft•lb)
Cylinder head bolt 45 mm (1.77 in)
20 Nm (2.0 m•kg, 15 ft•lb)
NOTE:
• Apply oil to the bearing surface of (upper) cylinder head bolt.
Further, apply molybdenum disulfide grease
to thread part.
• Tighten the cylinder head bolts in the proper
tightening sequence as shown.
4. Install:
• Camshaft sprocket
• Dowel pin
• Timing chain

4-12

ENG

CYLINDER HEAD

a. Turn the Pickup coil rotor counterclockwise.
b. Align the “I” mark
on the Pickup coil rotor
with the stationary pointer
on the crankcase cover.
c. Remove the wire from the timing chain.
d. Install the timing chain onto the camshaft
sprocket, and then install the camshaft
sprocket onto the camshaft.
NOTE:
• When installing the camshaft sprocket, be
sure to keep the timing chain as tight as possible on the exhaust side.
• Align the pin
on the camshaft with the slot
in the camshaft sprocket.

CAUTION:
Do not turn the crankshaft when installing
the camshaft(s) to avoid damage or
improper valve timing.
e. Align the “I” mark
on the camshaft
sprocket with the stationary pointer
on
the cylinder head.
f. While holding the camshaft, temporarily
tighten the camshaft sprocket bolts.
5. Install:
• Timing chain tensioner
a. While lightly pressing the timing chain tensioner rod by hand, turn the tensioner rod
fully clockwise with a thin screwdriver .
b. With the timing chain tensioner rod turned
all the way into the timing chain tensioner
housing (with the thin screwdriver still
installed), install the new gasket and the
timing chain tensioner
onto the body cylinder.
c. Tighten the timing chain tensioner bolts
to the specified torque.
10 Nm (1.0 m•kg, 7.4 ft•lb)

d. Remove the screwdriver, make sure that
the timing chain tensioner rod releases, and
then tighten the cap bolt
to the specified
torque.

4-13

CYLINDER HEAD

ENG

6. Turn:
• Crankshaft
(several turns counterclockwise)
7. Check:
• “I” mark
Align the “I” mark on the pickup coil rotor
with the stationary pointer
on the crankcase cover.
• “I” mark
Align the “I” mark on the camshaft sprocket
with the stationary pointer
on the cylinder head.
Out of alignment → Correct.
Refer to the installation steps above.
8. Tighten:
• Camshaft sprocket bolt
Camshaft sprocket bolt
60 Nm (6.0 m•kg, 44 ft•lb)

CAUTION:
Be sure to tighten the camshaft sprocket
bolts to the specified torque to avoid the
possibility of the bolts coming loose and
damaging the engine.
9. Measure:
• Valve clearance
Out of specification → Adjust.
Refer to “ADJUSTING THE VALVE CLEARANCE” in chapter 3.

4-14

ROCKER ARM, CAMSHAFT

ENG

ROCKER ARM, CAMSHAFT

Order

1
2
3
4
5
6
7

Job/Parts to remove
Q’ty
Remarks
Removing the rocker arms and camRemove the parts in the order listed.
shaft
Cylinder head
Refer to “CYLINDER HEAD”.
Lock plate
1
Locknut/valve clearance adjusting
2/2
screw
Camshaft
1
Intake rocker arm shaft
1
Intake rocker arm
1
Exhaust rocker arm shaft
1
Exhaust rocker arm
1
For installation, reverse the removal
procedure.

4-15

ROCKER ARM, CAMSHAFT

ENG

REMOVING THE ROCKER ARMS AND
CAMSHAFT
1. Loosen:
• Locknut
• Valve clearance adjusting screw
2. Remove:
• Stopper plate

3. Remove:
• Camshaft
• Bearing
NOTE:
Screw 10 mm (0.396 in) bolt
into the
threaded end of the camshaft and then pull out
the camshaft.

4. Remove:
• Intake rocker arm shaft
• Exhaust rocker arm shaft
• Intake rocker arm
• Exhaust rocker arm
NOTE:
Remove the rocker arm shafts with the slide
hammer bolt
and weight .
Slide hammer bolt
90890-01083
Slide hammer bolt 6 mm
YU-01083-1
Weight
90890-01084, YU-01083-3

4-16

ROCKER ARM, CAMSHAFT

ENG

CHECKING THE CAMSHAFT
1. Check:
• Bearing
Damage/wear → Replace.
2. Check:
• Camshaft lobes
Blue discoloration/pitting/scratches
Replace the camshaft.

→

3. Measure:
• Camshaft lobe dimensions
and
Out of specification → Replace the camshaft.
Camshaft lobe dimension
Intake A
36.890 ~ 36.990 mm
(1.4524 ~ 1.4563 in)
Limit
36.790 mm (1.4484 in)
Intake B
30.111 ~ 30.211 mm
(1.1855 ~ 1.1894 in)
Limit
30.011 mm (1.1815 in)
Exhaust A
36.891 ~ 36.991 mm
(1.4524 ~ 1.4563 in)
Limit
36.791 mm (1.4485 in)
Exhaust B
30.092 ~ 30.192 mm
(1.1847 ~ 1.1887 in)
Limit
29.992 mm (1.1808 in)

4. Check:
• Camshaft oil passage
Obstruction → Blow out with compressed
air.

4-17

ROCKER ARM, CAMSHAFT

ENG

CHECKING THE ROCKER ARMS AND
ROCKER ARM SHAFTS
The following procedure applies to all of the
rocker arms and rocker arm shafts.
1. Check:
• Rocker arms
• Valve clearance adjusting screws
Damage/wear → Replace.
2. Check:
• Rocker arm shaft
Blue discoloration/excessive wear/pitting/
scratches → Replace or check the lubrication system.
3. Measure:
• Rocker arm inside diameter
Out of specification → Replace.
Rocker arm inside diameter
12.000 ~ 12.018 mm
(0.4724 ~ 0.4731 in)
Limit
12.036 mm (0.4739 in)
4. Measure:
• Rocker arm shaft outside diameter
Out of specification → Replace.
Rocker arm shaft outside diameter
11.981 ~ 11.991 mm
(0.4717 ~ 0.4721 in)
Limit
11.950 mm (0.4705 in)
5. Calculate:
• Rocker-arm-to-rocker-arm-shaft clearance
NOTE:
Calculate the clearance by subtracting the
rocker arm shaft outside diameter from the
rocker arm inside diameter.
Out of specification → Replace the defective part(s).
Rocker-arm-to-rocker-arm-shaft
clearance
0.009 ~ 0.037 mm
(0.0004 ~ 0.0015 in)

4-18

ROCKER ARM, CAMSHAFT

ENG

INSTALLING THE CAMSHAFT AND
ROCKER ARMS
1. Lubricate:
• Camshaft
Recommended lubricant
Camshaft
Molybdenum disulfide oil
Camshaft bearing
Engine oil
2. Lubricate:
• Rocker arm
• Rocker arm shaft
Recommended lubricant
Rocker arm
Molybdenum disulfide oil
Rocker arm shaft
Engine oil
3. Install:
• Exhaust rocker arm
• Exhaust rocker arm shaft
NOTE:
Make sure the exhaust rocker arm shaft is
completely pushed into the cylinder head.

4. Install:
• Intake rocker arm
• Intake rocker arm shaft
NOTE:
• Insert a cylinder head bolt (226 mm)
into
the hole in the cylinder head and the intake
rocker arm shaft as shown.
• Install the intake rocker arm shaft so that
groove
is horizontal and aligning the notch
of the pointed end
with the hole in the cylinder head.

4-19

ROCKER ARM, CAMSHAFT

ENG

5. Install:
• Camshaft
NOTE:
Screw a 10 mm bolt into the threaded end of
the camshaft and then install the camshaft.
6. Install:
• Lock plate
7. Tighten:
• Lock plate bolts
Lock plate bolt
8 Nm (0.8 m•kg, 5.9 ft•lb)
LOCTITE®

4-20

VALVES AND VALVE SPRINGS

ENG

VALVES AND VALVE SPRINGS

Order

1
2
3
4
5
6
7
8
9

Job/Parts to remove
Removing the valves and valve
springs
Cylinder head
Rocker arm
Camshaft
Valve cotter
Valve spring retainer
Outer valve spring
Inner valve spring
Intake valve
Exhaust valve
Valve stem seal
Valve spring seat
Valve guide

Q’ty

Remarks
Remove the parts in the order listed.
Refer to “CYLINDER HEAD”.
Refer to “ROCKER ARM, CAMSHAFT”.

4
2
2
2
1
1
2
2
2
For installation, reverse the removal
procedure.

4-21

VALVES AND VALVE SPRINGS

ENG

REMOVING THE VALVES
The following procedure applies to all of the
valves and related components.
NOTE:
Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve
seats), make sure the valves properly seal.

1. Check:
• Valve sealing
Leakage at the valve seat → Check the
valve face, valve seat, and valve seat width.
Refer to “CHECKING THE VALVE SEATS”.
a. Pour a clean solvent
into the intake and
exhaust ports.
b. Check that the valves properly seal.
NOTE:
There should be no leakage at the valve seat
.
.

2. Remove:
• Valve cotters
NOTE:
Remove the valve cotters by compressing the
valve spring with the valve spring compressor
and the valve spring compressor attachment
.
Valve spring compressor
90890-04019
YM-04019
Valve spring compressor
attachment
90890-01243
Valve spring compressor adapter
(26 mm)
YM-01253-1

4-22

VALVES AND VALVE SPRINGS

ENG

3. Remove:
• Upper spring seat
• Inner valve spring
• Outer valve spring
• Valve
• Lower spring seat
• Valve stem seal
NOTE:
Identify the position of each part very carefully
so that it can be reinstalled in its original place.

CHECKING THE VALVES AND VALVE
GUIDES
The following procedure applies to all of the
valves and valve guides.
1. Measure:
• Valve-stem-to-valve-guide clearance
Out of specification → Replace the valve
guide.
Valve-stem-to-valve-guide clearance =
Valve guide inside diameter
Valve stem diameter
Valve-stem-to-valve-guide
clearance
Valve-stem-to-valve-guide
clearance (intake)
0.010 ~ 0.037 mm
(0.0004 ~ 0.0015 in)
Limit
0.080 mm (0.003 in)
Valve-stem-to-valve-guide
clearance (exhaust)
0.025 ~ 0.052 mm
(0.0010 ~ 0.0020 in)
Limit
0.100 mm (0.004 in)

4-23

VALVES AND VALVE SPRINGS

ENG

2. Replace:
• Valve guide
NOTE:
To ease valve guide removal and installation,
and to maintain the correct fit, heat the cylinder
head to 100°C (212°F) in an oven.
a. Remove the valve guide with the valve
guide remover .
b. Install the new valve guide with the valve
guide installer
and valve guide remover
.
c. After installing the valve guide, bore the
valve guide with the valve guide reamer
to obtain the proper valve-stem-to-valveguide clearance.
NOTE:
After replacing the valve guide, reface the
valve seat.
Valve guide remover (ø6)
90890-04064
Valve guide remover (6.0 mm)
YM-04064-A
Valve guide installer (ø6)
90890-04065
Valve guide installer (6.0 mm)
YM-04065-A
Valve guide reamer (ø6)
90890-04066
Valve guide reamer (6.0 mm)
YM-04066
3. Eliminate:
• Carbon deposits
(from the valve face and valve seat)
4. Check:
• Valve face
Pitting/wear → Grind the valve face.
• Valve stem end
Mushroom shape or diameter larger than
the body of the valve stem → Replace the
valve.

4-24

VALVES AND VALVE SPRINGS

ENG

5. Measure:
• Valve margin thickness D
Out of specification → Replace the valve.
Valve margin thickness
Valve margin thickness D (intake)
0.80 ~ 1.20 mm
(0.0315 ~ 0.0472 in)
Valve margin thickness D
(exhaust)
0.80 ~ 1.20 mm
(0.0315 ~ 0.0472 in)
6. Measure:
• Valve stem runout
Out of specification → Replace the valve.
NOTE:
• When installing a new valve, always replace
the valve guide.
• If the valve is removed or replaced, always
replace the oil seal.
Valve stem runout
0.01 mm (0.0004 in)

CHECKING THE VALVE SEATS
The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
• Carbon deposits
(from the valve face and valve seat)
2. Check:
• Valve seat
Pitting/wear → Replace the cylinder head.

4-25

VALVES AND VALVE SPRINGS

ENG

3. Measure:
• Valve seat width
Out of specification → Replace the cylinder
head.
Valve seat width
Valve seat width C (intake)
0.90 ~ 1.10 mm
(0.0354 ~ 0.0433 in)
Valve seat width C (exhaust)
0.90 ~ 1.10 mm
(0.0354 ~ 0.0433 in)
a. Apply Mechanic’s blueing dye (Dykem)
onto the valve face.
b. Install the valve into the cylinder head.
c. Press the valve through the valve guide and
onto the valve seat to make a clear impression.
d. Measure the valve seat width.
NOTE:
Where the valve seat and valve face contacted
one another, the blueing will have been
removed.

4. Lap:
• Valve face
• Valve seat
NOTE:
After replacing the cylinder head or replacing
the valve and valve guide, the valve seat and
valve face should be lapped.
Valve lapper
90890-04101
Valve lapping tool
YM-A8998

4-26

VALVES AND VALVE SPRINGS

ENG

a. Apply a coarse lapping compound
valve face.

to the

CAUTION:
Do not let the lapping compound enter the
gap between the valve stem and the valve
guide.
b. Apply molybdenum disulfide oil onto the
valve stem.
c. Install the valve into the cylinder head.
d. Turn the valve until the valve face and valve
seat are evenly polished, then clean off all
of the lapping compound.
NOTE:
For the best lapping results, lightly tap the
valve seat while rotating the valve back and
forth between your hands.
e. Apply a fine lapping compound to the valve
face and repeat the above steps.
f. After every lapping procedure, be sure to
clean off all of the lapping compound from
the valve face and valve seat.
g. Apply Mechanic’s blueing dye (Dykem)
onto the valve face.
h. Install the valve into the cylinder head.
i. Press the valve through the valve guide and
onto the valve seat to make a clear impression.
j. Measure the valve seat width
again. If
the valve seat width is out of specification,
reface and lap the valve seat.

4-27

VALVES AND VALVE SPRINGS

ENG

CHECKING THE VALVE SPRINGS
The following procedure applies to all of the
valve springs.
1. Measure:
• Valve spring free length
Out of specification → Replace the valve
spring.
Inner spring
Free length (intake)
36.17 mm (1.42 in)
Free length (exhaust)
36.17 mm (1.42 in)
Outer spring
Free length (intake)
36.63 mm (1.44 in)
Free length (exhaust)
36.63 mm (1.44 in)

2. Measure:
• Compressed valve spring force
Out of specification → Replace the valve
spring.
Compressed valve spring force
Installed length

Inner spring
Installed compression spring
force (intake)
75.00 ~ 91.70 N (7.65 ~
9.35 kg) (16.86 ~ 20.62 lb)
Installed compression spring
force (exhaust)
75.00 ~ 91.70 N (7.65 ~
9.35 kg) (16.86 ~ 20.62 lb)
Installed length (intake)
30.50 mm (1.20 in)
Installed length (exhaust)
30.50 mm (1.20 in)
Outer spring
Installed compression spring
force (intake)
128.50 ~ 157.90 N (13.10 ~
16.10 kg) (28.89 ~ 35.50 lb)
Installed compression spring
force (exhaust)
128.50 ~ 157.90 N (13.10 ~
16.10 kg) (28.89 ~ 35.50 lb)
Installed length (intake)
32.00 mm (1.26 in)
Installed length (exhaust)
32.00 mm (1.26 in)

4-28

VALVES AND VALVE SPRINGS

ENG

3. Measure:
• Valve spring tilt
Out of specification → Replace the valve
spring.
Inner spring
Spring tilt (intake)
2.5°/1.60 mm (2.5°/0.063 in)
Spring tilt (exhaust)
2.5°/1.60 mm (2.5°/0.063 in)
Outer spring
Spring tilt (intake)
2.5°/1.60 mm (2.5°/0.063 in)
Spring tilt (exhaust)
2.5°/1.60 mm (2.5°/0.063 in)

INSTALLING THE VALVES
The following procedure applies to all of the
valves and related components.
1. Deburr:
• Valve stem end
(with an oil stone)
2. Lubricate:
• Valve stem
• Valve stem seal
(with the recommended lubricant)
Recommended lubricant
Molybdenum disulfide oil
3. Install:
• Valve spring seat
• Valve stem seal
• Valve
• Inner valve spring
• Outer valve spring
• Upper spring seat
(into the cylinder head)
NOTE:
Install the valve springs with the larger pitch
facing up.
Larger pitch
Smaller pitch

4-29

VALVES AND VALVE SPRINGS

ENG

4. Install:
• Valve cotters
NOTE:
Install the valve cotters by compressing the
valve spring with the valve spring compressor
and the valve spring compressor attachment
.
Valve spring compressor
90890-04019, YM-04019
Valve spring compressor
attachment
90890-01243
Valve spring compressor adapter
(26 mm)
YM-01253-1

5. To secure the valve cotters onto the valve
stem, lightly tap the valve tip with a softface hammer.

CAUTION:
Hitting the valve tip with excessive force
could damage the valve.

4-30

CYLINDER AND PISTON

ENG

CYLINDER AND PISTON

10 Nm (1.0 m•kg, 7.4 ft•lb)

17 Nm (1.7 m•kg, 13 ft•lb)

Order

1
2
3
4
5
6
7
8

Job/Parts to remove
Removing the cylinder and piston
Cylinder head
Oil delivery pipe
Cylinder
Dowel pin
Cylinder gasket
Piston pin clip
Piston pin
Piston
Piston ring set

Q’ty

Remarks
Remove the parts in the order listed.
Refer to “CYLINDER HEAD”.

1
1
2
1
2
1
1
1
For installation, reverse the removal
procedure.

4-31

CYLINDER AND PISTON

ENG

+

REMOVING THE PISTON
1. Remove:
• Piston pin clips
• Piston pin
• Piston
NOTE:
• Before removing the piston pin clip, cover the
crankcase opening with a clean rag to prevent the piston pin clip from falling into the
crankcase.
• Before removing each piston pin, deburr the
clip groove and pin hole area. If the piston pin
groove is deburred and the piston pin is still
difficult to remove, use the piston pin puller
.
Piston pin puller set
90890-01304
Piston pin puller
YU-01304

CAUTION:
Do not use a hammer to drive the piston
pin out.

2. Remove:
• Top ring
• 2nd ring
• Oil ring
NOTE:
When removing a piston ring, open the end
gap with your fingers and lift the other side of
the ring over the piston crown.

CHECKING THE CYLINDER AND PISTON
1. Check:
• Piston wall
• Cylinder wall
Vertical scratches → Rebore or replace the
cylinder, and replace the piston and piston
rings as a set.
2. Measure:
• Piston-to-cylinder clearance

4-32

CYLINDER AND PISTON

ENG

a. Measure cylinder bore “C” with the cylinder
bore gauge.
NOTE:
Measure cylinder bore “C” by taking side-toside and front-to-back measurements of the
cylinder. Then, find the average of the measurements.

Bore “C”
74.000 ~ 74.016 mm
(2.9134 ~ 2.9140 in)
Wear limit
74.100 mm (2.9173 in)
“C” = maximum of D1 ~ D6
b. If out of specification, rebore or replace the
cylinder, and replace the piston and piston
rings as a set.
c. Measure piston skirt diameter D
with the
micrometer.
5 mm (0.20 in) from the bottom edge of the piston

Piston size diameter “D”
Standard
73.983 ~ 73.998 mm
(2.9127 ~ 2.9133 in)
d. If out of specification, replace the piston
and piston rings as a set.
e. Calculate the piston-to-cylinder clearance
with the following formula.
Piston-to-cylinder clearance =
Cylinder bore “C” Piston skirt diameter “D”

4-33

CYLINDER AND PISTON

ENG

Piston-to-cylinder clearance
0.010 ~ 0.025 mm
(0.0004 ~ 0.0010 in)
Limit
0.15 mm (0.006 in)
f. If out of specification, rebore or replace the
cylinder, and replace the piston and piston
rings as a set.

CHECKING THE PISTON RINGS
1. Measure:
• Piston ring side clearance
Out of specification → Replace the piston
and piston rings as a set.
NOTE:
Before measuring the piston ring side clearance, eliminate any carbon deposits from the
piston ring grooves and piston rings.
Piston ring
Top ring
Ring side clearance
0.030 ~ 0.065 mm
(0.0012 ~ 0.0026 in)
Limit
0.115 mm (0.0045 in)
2nd ring
Ring side clearance
0.020 ~ 0.055 mm
(0.0008 ~ 0.0022 in)
Limit
0.115 mm (0.0045 in)

4-34

CYLINDER AND PISTON

ENG

2. Install:
• Piston ring
(into the cylinder)
NOTE:
Level the piston ring into the cylinder with the
piston crown.
40 mm (1.476 in)

3. Measure:
• Piston ring end gap
Out of specification → Replace the piston
ring.
NOTE:
The oil ring expander spacer’s end gap cannot
be measured. If the oil ring rail’s gap is excessive, replace all three piston rings.
Piston ring
Top ring
End gap (installed)
0.19 ~ 0.31 mm
(0.007 ~ 0.012 in)
Limit
0.56 mm (0.022 in)
2nd ring
End gap (installed)
0.30 ~ 0.45 mm
(0.012 ~ 0.018 in)
Limit
0.80 mm (0.032 in)
Oil ring
End gap (installed)
0.10 ~ 0.35 mm
(0.004 ~ 0.014 in)

4-35

CYLINDER AND PISTON

ENG

CHECKING THE PISTON PIN
1. Check:
• Piston pin
Blue discoloration/grooves → Replace the
piston pin and then check the lubrication
system.
2. Measure:
• Piston pin outside diameter
Out of specification → Replace the piston
pin.
Piston pin outside diameter
16.991 ~ 17.000 mm
(0.6689 ~ 0.6693 in)
Limit
16.971 mm (0.6681 in)

3. Measure:
• Piston pin bore diameter
Out of specification → Replace the piston.
Piston pin bore inside diameter
17.002 ~ 17.013 mm
(0.6694 ~ 0.6698 in)
Limit
17.043 mm (0.6710 in)
4. Calculate:
• Piston-pin-to-piston-pin-bore clearance
Out of specification → Replace the piston
pin and piston as a set.
Piston-pin-to-piston-pin-bore clearance =
Piston pin bore diameter
Piston pin outside diameter
Piston-pin-to-piston-pin-bore
clearance
0.002 ~ 0.022 mm
(0.0001 ~ 0.0009 in)
Limit
0.072 mm (0.0028 in)

4-36

CYLINDER AND PISTON

ENG

INSTALLING THE PISTON AND CYLINDER
1. Install:
• Lower oil ring rail
• Oil ring expander
• Upper oil ring rail
• 2nd ring
• Top ring
NOTE:
Be sure to install the piston rings so that the
“T” marks or numbers face up.

2. Install:
• Piston
• Piston pin
• Piston pin clips
NOTE:
• Apply engine oil the piston pin.
• Make sure the dot
on the piston points
towards the exhaust side of the cylinder.
• Before installing the piston pin clip, cover the
crankcase opening with a clean rag to prevent the clip from falling into the crankcase.
3. Install:
• O-ring
• Cylinder gasket
• Dowel pins
4. Lubricate:
• Piston
• Piston rings
• Cylinder
(with the recommended lubricant)
Recommended lubricant
Engine oil
New

4-37

CYLINDER AND PISTON

ENG

5. Offset:
• Piston ring end gaps
Top ring
Upper oil ring rail
Oil ring expander
Lower oil ring rail
2nd ring
20 mm

6. Install:
• Cylinder
NOTE:
• While compressing the piston rings with one
hand, install the cylinder with the other hand.
• Pass the timing chain and timing chain guide
(exhaust side) through the timing chain cavity.
7. Tighten:
• Cylinder bolts
Cylinder bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)

4-38

CLUTCH

ENG

CLUTCH

73 Nm (7.3 m•kg, 54 ft•lb)

20 Nm (2.0 m•kg, 15 ft•lb)

10 Nm (1.0 m•kg, 7.4 ft•lb)
10 Nm (1.0 m•kg, 7.4 ft•lb)

Order

1
2
3
4
5
6
7
8
9

Job/Parts to remove
Removing the clutch cover
Engine oil
Cotter pin/Washer
Clevis pin
Brake pedal/Footrest
Oil delivery pipe
Oil cooler hose
O-ring
Right crankcase cover
Dowel pin
Crankcase cover gasket

Q’ty

Remarks
Remove the parts in the order listed.
Drain.

1/1
1
1/1
1
2
2
1
2
1
For installation, reverse the removal
procedure.

4-39

CLUTCH

ENG

8 Nm (0.8 m•kg, 5.9 ft•lb)

75 Nm (7.5 m•kg, 55 ft•lb)

80 Nm (8.0 m•kg, 59 ft•lb)

Order
1
2
3
4
5
6
7
8
9
10
11
12
13
14

Job/Parts to remove
Removing the clutch
Clutch spring
Pressure plate
Primary drive gear nut
Friction plate
Clutch plate
Clutch boss nut
Clutch boss
Thrust washer
Clutch housing
Claw washer
Primary drive gear
Locknut/Washer
Push rod1
Push plate

Q’ty
5
1
1
6
5
1
1
1
1
1
1
1/1
1
1

4-40

Remarks
Remove the parts in the order listed.

CLUTCH

ENG

8 Nm (0.8 m•kg, 5.9 ft•lb)

75 Nm (7.5 m•kg, 55 ft•lb)

80 Nm (8.0 m•kg, 59 ft•lb)

Order
15

Job/Parts to remove
Push rod 2/Ball

Q’ty
1/1

Remarks
For installation, reverse the removal
procedure.

4-41

CLUTCH

Order

1
2
3
4
5
6
7

Job/Parts to remove
Removing the push lever shaft
Shift pedal
Left crankcase cover
Clutch assembly
Clutch cable
Bolt
Push lever shaft
Torsion spring
Circlip
Oil seal
Bearing

Q’ty

ENG

Remarks
Remove the parts in the order listed.
Refer to “SHIFT SHAFT”.
Refer to “PICK UP COIL ROTOR AND
STARTER CLUTCH”.

1
1
1
1
1
1
1
For installation, reverse the removal
procedure.

4-42

CLUTCH

ENG

REMOVING THE CLUTCH
1. Remove:
• Bolt
• Clutch spring
NOTE:
Loosen the bolts in stages and in a crisscross
pattern.
2. Straighten the lock washer tab.
3. Loosen:
• Primary drive gear nut
• Clutch boss nut
NOTE:
• Place the aluminum plate
between clutch
housing
and primary drive gear
, and
then loosen the primary drive gear nut .
• While holding the clutch boss with the universal clutch holder
, loosen the clutch boss
nut .
Universal clutch holder
90890-04086, YM-91042

4. Remove:
• Clutch boss nut
• Lock washer
• Clutch boss
• Thrust washer
• Clutch housing

5. Remove:
• Primary drive gear nut
• Lock washer
• Claw washer
• Primary drive gear

4-43

CLUTCH

ENG

CHECKING THE FRICTION PLATES
The following procedure applies to all of the
friction plates.
1. Check:
• Friction plate
Damage/wear → Replace the friction plate.
2. Measure:
• Friction plate thickness
Out of specification → Replace the friction
plate.
NOTE:
Measure the friction plate at four places.
Friction plate thickness
2.9 ~ 3.1 mm (0.114 ~ 0.122 in)
Wear limit
2.8 mm (0.110 in)

CHECKING THE CLUTCH PLATES
The following procedure applies to all of the
clutch plates.
1. Check:
• Clutch plate
Damage → Replace the clutch plate.
2. Measure:
• Clutch plate warpage
(with a surface plate and thickness gauge
)
Out of specification → Replace the clutch
plate.
Warpage limit
0.2 mm (0.0079 in)

4-44

CLUTCH

ENG

CHECKING THE CLUTCH SPRINGS
The following procedure applies to all of the
clutch springs.
1. Check:
• Clutch spring
Damage → Replace the clutch spring.
2. Measure:
• Clutch spring free length
Out of specification → Replace the clutch
spring.
Clutch spring free length
47.80 mm (1.88 in)
Minimum length
46.50 mm (1.83 in)

CHECKING THE CLUTCH HOUSING
1. Check:
• Clutch housing dogs
Damage/pitting/wear → Deburr the clutch
housing dogs or replace the clutch housing.
NOTE:
Pitting on the clutch housing dogs will cause
erratic clutch operation.

CHECKING THE CLUTCH BOSS
1. Check:
• Clutch boss splines
Damage/pitting/wear → Replace the clutch
boss.
NOTE:
Pitting on the clutch boss splines will cause
erratic clutch operation.

CHECKING THE PRESSURE PLATE
1. Check:
• Pressure plate
Cracks/damage → Replace.

4-45

CLUTCH

ENG

CHECKING THE CLUTCH PUSH RODS
1. Check:
• Push lever shaft
• Push rod 2
• Ball
Cracks/damage/wear → Replace
defective part(s).

the

CHECKING THE PRIMARY DRIVE GEAR
1. Check:
• Primary drive gear
Damage/wear → Replace the primary drive
and primary driven gears as a set.
Excessive noise during operation →
Replace the primary drive and primary
driven gears as a set.
2. Check:
• Primary-drive-gear-to-primary-driven-gear
free play
Free play exists → Replace the primary
drive and primary driven gears as a set.

INSTALLING THE CLUTCH
1. Install:
• Primary drive gear
• Claw washer
• Lock washer
• Primary drive gear nut
2. Install:
• Clutch housing
• Thrust washer
• Clutch boss
• Lock washer
• Clutch boss nut
NOTE:
Make sure the teeth on the lock washer are
correctly aligned with the grooves on the clutch
boss.

4-46

CLUTCH

ENG

3. Tighten:
• Clutch boss nut
• Primary drive gear nut
Clutch boss nut
75 Nm (7.5 m•kg, 55 ft•lb)
Primary drive gear nut
80 Nm (8.0 m•kg, 59 ft•lb)
NOTE:
• While holding the clutch boss with the universal clutch holder
, tighten the clutch boss
nut.
• Place the aluminum plate
between primary drive gear
and clutch housing
,
and then tighten the primary drive gear nut.
Universal clutch holder
90890-04086, YM-91042
4. Bend the lock washer tab along a flat side
of the nut.
5. Lubricate:
• Friction plates
• Clutch plates
(with the recommended lubricant)
)

Recommended lubricant
Engine oil

6. Install:
• Friction plates (6 piece)
• Clutch plates (5 piece)
NOTE:
First, install a friction plate and then alternate
between a clutch plate and a friction plate.

4-47

CLUTCH

ENG

7. Install:
• Bearing
• Oil seal
• Circlip
• Torsion spring
• Push lever shaft
• Bolt
• Clutch cable
NOTE:
After installing the clutch cable, bend the push
lever shaft tab along a flat side of the nut.
8. Install:
• Push rod 2
• Ball
• Push rod 1
• Push plate
• Washer
• Locknut
• Pressure plate
• Clutch spring
• Bolt
9. Tighten:
• Clutch spring bolt
• Locknut
Clutch spring bolt
8 Nm (0.8 m•kg, 5.9 ft•lb)
Locknut
8 Nm (0.8 m•kg, 5.9 ft•lb)
NOTE:
Tighten the clutch spring bolts in stages and in
a crisscross pattern.

10.Check:
• Push lever position
Push lever mark
and crankcase mark
not aligned → Correct.
NOTE:
Push the push lever in direction
and make
sure the marks are aligned.

4-48

ENG

CLUTCH
11.Adjust:
• Push lever position

a. Loosen the locknut .
b. Turn the adjusting screw
in or out until
the marks are aligned.
c. Hold the adjusting screw to prevent it from
moving and then tighten the locknut to
specification.
8 Nm (0.8 m•kg, 5.9 ft•lb)

CAUTION:
Do not overtighten the locknut since this
will remove the free play between both
push rods.
12.Check:
• Clutch cable free play
Refer to “ADJUSTING THE CLUTCH
CABLE FREE PLAY” in chapter 3.
Clutch lever free play
5 ~ 10 mm (0.20 ~ 0.39 in)
13.Install:
• Spacer
• Dowel pin
• Crankcase cover gasket
14.Install:
• Right crankcase cover
15.Install:
• Crankcase cover bolts M6 × 50 mm ,
• Copper washers to ,
• Crankcase cover bolts M6 × 40 mm
~
• Crankcase cover bolts M6 × 25 mm
~
• Oil filter element cover bolt M6 × 70 mm
16.Tighten:
• Crankcase cover bolts
~
• Oil filter element cover bolt
NOTE:
Tighten the bolts in stages, using a crisscross
pattern.
Crankcase cover bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)
Oil filter element cover bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)

4-49

OIL PUMP AND BLANCER WEIGHT GEAR

ENG

OIL PUMP AND BLANCER WEIGHT GEAR

6 Nm (0.6 m•kg, 4.4 ft•lb)

55 Nm (5.5 m•kg, 41 ft•lb)

Order

1
2
3
4
5
6
7
8
9
10
11
12
13

Job/Parts to remove
Removing the oil pump and balancer weight gear
Right crankcase cover
Clutch
Primary drive gear
Balancer weight gear nut
Lock washer
Buffer boss
Balancer weight gear
Absorber plate
Compression spring
Dowel pin
Straight key
Spacer
Circlip
Oil pump driven gear
Oil pump assembly
Gasket

Q’ty

Remarks
Remove the parts in the order listed.
Refer to “CLUTCH”.

1
1
1
1
1
6
3
1
1
1
1
1
1

4-50

OIL PUMP AND BLANCER WEIGHT GEAR

ENG

6 Nm (0.6 m•kg, 4.4 ft•lb)

55 Nm (5.5 m•kg, 41 ft•lb)

Order
14
15
16

Job/Parts to remove
Balancer drive gear
Oil strainer
Spacer

Q’ty
1
1
1

Remarks

For installation, reverse the removal
procedure.

4-51

OIL PUMP AND BLANCER WEIGHT GEAR

ENG

7 Nm (0.7 m•kg, 5.0 ft•lb)

Order

Job/Parts to remove
Disassembling the oil pump
Oil pump housing
Dowel pin
Outer rotor
Inner rotor
Dowel pin
Shaft
Oil pump cover

Q’ty

Remarks
Remove the parts in the order listed.

1
2
1
1
1
1
1
For assembly, reverse the disassembly
procedure.

4-52

OIL PUMP AND BLANCER WEIGHT GEAR

ENG

REMOVING THE BALANCER WEIGHT
GEAR AND OIL PUMP
1. Straighten the lock washer tab.
2. Remove:
• Balancer weight gear nut
• Lock washer
• Balancer weight gear
NOTE:
Place the aluminum plate
between balancer
drive gear
and balancer weight gear
,
and then loosen the balancer weight gear nut
.
3. Remove:
• Oil pump assembly

CHECKING THE OIL PUMP
1. Check:
• Oil pump driven gear
• Oil pump housing
• Oil pump cover
Cracks/damage/wear → Replace the
defective part(s).
2. Measure:
• Inner-rotor-to-outer-rotor-tip clearance
• Outer-rotor-to-oil-pump-housing clearance
• Oil-pump-housing-to-inner-rotor-and-outerrotor clearance
Out of specification → Replace the oil
pump.
Inner rotor
Outer rotor
Oil pump housing

4-53

OIL PUMP AND BLANCER WEIGHT GEAR

ENG

Inner-rotor-to-outer-rotor-tip
clearance
0.150 mm (0.0059 in)
Limit
0.23 mm (0.0091 in)
Outer-rotor-to-oil-pump-housing
clearance
0.100 ~ 0.151 mm
(0.0039 ~ 0.0059 in)
Limit
0.22 mm (0.0087 in)
Oil-pump-housing-to-inner-andouter-rotor clearance
0.04 ~ 0.09 mm
(0.0016 ~ 0.0035 in)
Limit
0.16 mm (0.0063 in)

3. Check:
• Oil pump operation
Rough movement → Repeat steps (1) and
(2) or replace the defective part(s).

CHECKING THE BALANCER WEIGHT
GEAR
1. Check:
• Balancer weight gear
• Buffer boss
• Compression spring
• Dowel pin
• Cracks/damage/wear → Replace.

4-54

OIL PUMP AND BLANCER WEIGHT GEAR

ENG

ASSENBLING THE BALANCER DRIVE
GEAR
1. Assemble:
• Dowel pin
• Compression spring
NOTE:
Install the dowel pins and compression springs
alternately as shown as.
2. Assemble:
• Buffer boss

INSTALLING THE OIL PUMP
1. Install:
• Gasket
• Oil pump
2. Tighten:
• Oil pump bolts
Oil pump bolt
6 Nm (0.6 m•kg, 4.4 ft•lb)
LOCTITE®

CAUTION:
After tightening the bolts, make sure the oil
pump turns smoothly.

4-55

OIL PUMP AND BLANCER WEIGHT GEAR

ENG

INSTALLING THE BALANCER WEIGHT
GEAR
1. Install:
• Balancer weight gear
• Lock washer
• Balancer weight gear nut
2. Tighten:
• Balancer weight gear nut
Balancer weight gear nut
55 Nm (5.5 m•kg, 41 ft•lb)
NOTE:
• Align the punch mark
in the balancer drive
gear with the punch mark
in the balancer
weight gear.
• Place the aluminum plate
between balancer drive gear
and balancer weight gear
, and then tighten the balancer weight gear
nut .
3. Bend the lock washer tab along a flat side
of the nut.

4-56

SHIFT SHAFT

ENG

SHIFT SHAFT

10 Nm (1.0 m•kg, 7.4 ft•lb)

10 Nm (1.0 m•kg, 7.4 ft•lb)

Order

1
2
3
4

Job/Parts to remove
Removing the shift shaft and
stopper lever
Right crankcase cover
Clutch
Shift pedal
Shift shaft assembly
Stopper lever
Torsion spring

Q’ty

Remarks
Remove the parts in the order listed.
Refer to “CLUTCH”.

1
1
1
1
For installation, reverse the removal
procedure.

4-57

SHIFT SHAFT

ENG

CHECKING THE SHIFT SHAFT
1. Check:
• Shift shaft
• Shift lever
Bends/damage/wear → Replace.
• Shift lever spring
Damage/wear → Replace.

CHECKING THE STOPPER LEVER
1. Check:
• Stopper lever
Bends/damage → Replace.
Roller turns roughly → Replace the stopper
lever.
• Torsion spring
Damage/wear → Replace.

INSTALLING THE SHIFT SHAFT
1. Install:
• Stopper lever
NOTE:
• Hook the ends of the stopper lever spring
onto the stopper lever and the crankcase
boss.
• Mesh the stopper lever with the shift drum
segment assembly.
2. Tighten:
• Stopper lever bolt
Stopper lever bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)
LOCTITE®

3. Install:
• Shift shaft
NOTE:
Install the shift shaft
by aligning the shift
shaft spring
with the stopper .

4-58

SHIFT SHAFT

ENG

4. Check:
• When the gear position is in Neutral, check
the length ( ,
) between the tip of the
and dowel pin
are equal.
shift lever
If not → Replace the shift shaft.

5. Install:
• Shift pedal
6. Tighten:
• Shift pedal bolt
Shift pedal bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)
7. Adjust:
• Shift pedal height
Refer to “ADJUSTING THE SHIFT PEDAL”
in chapter 3.

4-59

PICKUP COIL ROTOR AND STARTER CLUTCH

ENG

PICKUP COIL ROTOR AND STARTER CLUTCH

7 Nm (0.7 m•kg, 5.2 ft•lb)
10 Nm (1.0 m•kg, 7.4 ft•lb)

10 Nm (1.0 m•kg, 7.4 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
10 Nm (1.0 m•kg, 7.4 ft•lb)

60 Nm (6.0 m•kg, 44 ft•lb)

Order

1
2
3
4
5
6
7
8
9
10
11

Job/Parts to remove
Removing the pickup coil rotor and
starter clutch
Engine oil
Shift pedal
Drive sprocket cover

Q’ty

Remarks
Remove the parts in the order listed.

Starter idle gear cover/O-ring
Starter idler gear 1/shaft
Pickup coil rotor lead coupler
Left crankcase cover
Dowel pin
Crank case cover gasket
Stator coil assembly/pickup coil
Starter idler gear 2/shaft
Pickup coil rotor
Woodruff key
Starter wheel gear

1/1
1/1
2 Disconnect.
1
2
1
1/1
1/1
1
1
1

Drain.
Refer to “SHIFT SHAFT”.
Refer to “REAR SHOCK ABSORBER,
SWINGARM AND DRIVE CHAIN” in
chapter 6.

4-60

PICKUP COIL ROTOR AND STARTER CLUTCH

ENG

7 Nm (0.7 m•kg, 5.2 ft•lb)
10 Nm (1.0 m•kg, 7.4 ft•lb)

10 Nm (1.0 m•kg, 7.4 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
60 Nm (6.0 m•kg, 44 ft•lb)

Order
12
13
14

Job/Parts to remove
Bearing
Washer
Starter clutch assembly

Q’ty
1
1
1

10 Nm (1.0 m•kg, 7.4 ft•lb)

Remarks

For installation, reverse the removal
procedure.

4-61

PICKUP COIL ROTOR AND STARTER CLUTCH

ENG

REMOVING THE PICKUPCOIL ROTOR
1. Remove:
• Pickup coil rotor bolt
• Washer
NOTE:
• Loosen the pickup coil rotor bolt
while
holding the rotor with a sheave holder .
• Do not allow the sheave holder to touch the
projection on the rotor .
Sheave holder
90890-01701
Primary clutch holder
YS-01880-A

2. Remove:
• Pickup coil rotor
NOTE:
Remove the rotor using flywheel puller
Flywheel puller
90890-01362
Heavy duty puller
YU-33270-B
Bolt (M8 × 80 mm)
90890-01359
3. Remove:
• Woodruff key

4. Remove:
• Starter idle gear 2
• Starter wheel gear
• Bearing
• Washer

4-62

.

PICKUP COIL ROTOR AND STARTER CLUTCH

ENG

CHECKING THE STARTER CLUTCH
1. Check:
• Starter clutch rollers
Damage/wear → Replace the starter
clutch.

2. Check:
• Starter idle gear
• Starter wheel gear
• Starter clutch gear
Burrs/chips/roughness/wear → Replace
the defective part(s).
3. Check:
• Starter clutch gear’s contacting surfaces
Damage/pitting/wear → Replace the
starter clutch gear.
4. Check:
• Starter clutch operation
a. Install the starter wheel gear
onto the
starter clutch
and hold the starter clutch.
b. When turning the starter wheel gear clockwise
, the starter clutch and the starter
wheel gear should engage, otherwise the
starter clutch is faulty and must be
replaced.
c. When turning the starter wheel gear counterclockwise , it should turn freely, otherwise the starter clutch is faulty and must be
replaced.
5. Check:
• Shaft
Damage/fatigue/wear
defective part(s).

4-63

→

Replace

the

PICKUP COIL ROTOR AND STARTER CLUTCH

ENG

INSTALLING THE PICKUP COIL ROTOR
1. Install:
• Washer
• Bearing
• Starter wheel gear
• Starter idle gear 2

2. Install:
• Woodruff key
• Pickup coil rotor
• Washer
• Pickup coil rotor bolt
NOTE:
• Clean the tapered portion of the crankshaft
and the rotor hub.
• When installing the rotor, make sure the woodruff key is properly seated in the key way of
the crankshaft.

3. Tighten:
• Pickup coil rotor bolt
Pickup coil rotor bolt
60 Nm (6.0 m•kg, 44 ft•lb)
NOTE:
• Tighten the pickup coil rotor bolt
while
holding the rotor with a sheave holder .
• Do not allow the sheave holder to touch the
projection on the rotor .
Sheave holder
90890-01701
Primary clutch holder
YS-01880-A

4-64

PICKUP COIL ROTOR AND STARTER CLUTCH

ENG

4. Install:
• Stater coil
• Pickup coil
5. Tighten:
• Stater coil bolts
• Pickup coil bolts
• Left crankcase cover bolt
Stater coil bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)
LOCTITE®
Pickup coil bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)
LOCTITE®
Left crankcase cover bolt
7 Nm (0.7 m•kg, 5.2 ft•lb)
LOCTITE®
6. Install:
• Dowel pin
• Crankcase cover gasket
7. Install:
• Left crankcase cover
8. Install:
~
• Crankcase cover bolts M6 × 30 mm
• Crankcase cover bolt M6 × 45 mm
• Crankcase cover bolts M6 × 40 mm
~
9. Tighten:
~
• Crankcase cover bolts
NOTE:
Tighten the bolts in stages and in a crisscross
pattern as shown.
Crankcase cover bolt
10 Nm (1.0 m•kg, 7.2 ft•lb)
10.Install:
• Starter idle gear 1
• Shaft
11.Install:
• O-ring
• Starter idle gear cover
12.Tighten:
• Starter idle gear cover bolt
Starter idle gear cover bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)

4-65

ENG

CRANKCASE

CRANKCASE

8 Nm (0.8 m•kg, 5.9 ft•lb)

1
2

4
5

3

7
6

5

10 Nm (1.0 m•kg, 7.4 ft•lb)
20 Nm (2.0 m•kg, 15 ft•lb)

Order

Job/Parts to remove
Separating the crankcase
Engine
Cylinder head
Cylinder
Clutch
Oil pump

Q’ty

Balancer weight gear
Shift shaft
Pickup coil rotor
1
2
3
4
5
6

Timing chain guide (intake side)
Timing chain
Crankshaft sprocket
Right crankcase
Dowel pin
Left crankcase

Remarks
Remove the parts in the order listed.
Refer to “ENGINE REMOVAL”.
Refer to “CYLINDER HEAD”.
Refer to “CYLINDER AND PISTON”.
Refer to “CLUTCH”.
Refer to “OIL PUMP AND BLANCER
WEIGHT GEAR”.
Refer to “SHIFT SHAFT”.
Refer to “PICKUP COIL ROTOR AND
STARTER CLUTCH”.

1
1
1
1
2
1

4-66

ENG

CRANKCASE

8 Nm (0.8 m•kg, 5.9 ft•lb)

1
2

4
5

3

7
6

5

10 Nm (1.0 m•kg, 7.4 ft•lb)
20 Nm (2.0 m•kg, 14.8 ft•lb)

Order
7

Job/Parts to remove
Spacer

Q’ty
1

Remarks
For installation, reverse the removal
procedure.

4-67

CRANKCASE

ENG

2
2

2
2
2
2
1
2

2

1

Order

1
2

Job/Parts to remove
Removing the bearing
Crankshaft assembly
Main axle assembly/drive axle assembly
Oil seal
Bearing

Q’ty

Remarks
Remove the parts in the order listed.
Refer to “CRANKSHAFT ASSEMBLY”.
Refer to “TRANSMISSION”.

2
8
For installation, reverse the removal
procedure.

4-68

CRANKCASE

ENG

DISASSEMBLING THE CRANKCASE
1. Remove:
• Timing chain guide (intake side)
• Timing chain
• Crankshaft sprocket

2. Remove:
• Neutral switch
• Crankcase bolts M6 × 70 mm
~
• Copper washers
• Crankcase bolts M6 × 60 mm ,
• Crankcase bolts M6 × 55 mm
~
• Crankcase bolts M6 × 45 mm
~
NOTE:
Loosen each bolt 1/4 of a turn at a time, in
stages and in a crisscross pattern. After all of
the bolts are fully loosened, remove them.

3. Turn:
• Shift drum segment
NOTE:
Turn the shift drum segment
to the position
shown in the illustration. In this position, the
shift drum segment’s teeth will not contact the
crankcase during crankcase separation.
4. Remove:
• Right crankcase

CAUTION:
• First check that the shift drum segment’s
teeth and the drive axle circlip are properly positioned, then remove the right
crankcase.
• Do not damage the crankcase mating surfaces.

4-69

CRANKCASE

ENG

CHECKING THE CRANKCASE
1. Thoroughly wash the crankcase halves in a
mild solvent.
2. Thoroughly clean all the gasket surfaces
and crankcase mating surfaces.
3. Check:
• Crankcase
Cracks/damage → Replace.
• Oil delivery passages
Obstruction → Blow out with compressed
air.

ASSEMBLING THE CRANKCASE
1. Apply:
• Yamaha bond No.1215 (Three Bond
No.1215®)
(onto the crankcase mating surfaces)
Yamaha bond No.1215
(Three Bond No.1215®)
90890-85505
NOTE:
Do not allow any sealant to come into contact
with the oil gallery.
2. Install:
• Dowel pins
3. Install:
• Right crankcase
(onto the left crankcase)
NOTE:
Tap lightly on the right crankcase with a softface hammer.

4-70

CRANKCASE

ENG

4. Install:
• Crankcase bolts M6 × 70 mm
• Copper washers to
~ .
• Crankcase bolts M6 × 60 mm
• Crankcase bolts M6 × 55 mm
• Crankcase bolts M6 × 45 mm
5. Tighten:
• Crankcase bolts
~

~
,
~
~

Crankcase bolt
10 Nm (1.0 m•kg, 7.4 ft•lb)
NOTE:
Tighten each bolt 1/4 of a turn at a time, in
stages and in a crisscross pattern.
6. Install:
• Neutral switch

7. Install:
• Crankshaft sprocket
• Timing chain guide (intake side)
• Timing chain
8. Tighten:
• Timing chain guide (intake side) bolt
Timing chain guide (intake side)
bolt
8 Nm (0.8 m•kg, 5.9 ft•lb)
LOCTITE®
9. Apply:
• Engine oil
(onto the crankshaft pins bearings and oil
delivery holes)
10.Check:
• Crankshaft and transmission operation
Rough movement → Repair.

4-71

CRANKSHAFT ASSEMBLY

ENG

CRANKSHAFT ASSEMBLY

3
2
4

5

1

Order

1
2
3
4
5

Job/Parts to remove
Removing the crankshaft assembly
Crankcase
Balancer weight
Crankshaft assembly
Dowel pin
Plunger seal
Bearing

Q’ty

Remarks
Remove the parts in the order listed.
Refer to “CRANKCASE”.

1
1
1
1
1
For installation, reverse the removal
procedure.

4-72

CRANKSHAFT ASSEMBLY

ENG

REMOVING THE CRANKSHAFT ASSEMBLY
1. Remove:
• Balancer weight
• Crankshaft assembly
NOTE:
• Remove the crankshaft assembly with the
crankcase separating tool .
• Make sure the crankcase separating tool is
centered over the crankshaft assembly.
Crankcase separating tool
90890-01135
Crankcase separator
YU-01135-B

REMOVING THE PLUNGER SEAL
1. Remove:
• Dowel pin
• Plunger seal
• Compression spring
Remove the plunger seal and compression
spring, push the plunger seal lightly and
remove the dowel pin.

CHECKING THE CRANKSHAFT AND
CONNECTING ROD
1. Measure:
• Crankshaft runout
Out of specification → Replace the crankshaft, bearing or both.
NOTE:
Turn the crankshaft slowly.
Runout limit C
0.03 mm (0.0012 in)

4-73

CRANKSHAFT ASSEMBLY

ENG

2. Measure:
• Big end side clearance
Out of specification → Replace the big end
bearing, crankshaft pin, or connecting rod.
Big end side clearance D
0.350 ~ 0.650 mm
(0.0138 ~ 0.0256 in)
3. Measure:
• Crankshaft width
Out of specification → Replace the crankshaft.
Width A
69.25 ~ 69.30 mm
(2.726 ~ 2.728 in)
4. Check:
• Crankshaft sprocket
Damage/wear → Replace the crankshaft.
• Bearing
Cracks/damage/wear → Replace the
crankshaft.
5. Check:
• Crankshaft journal oil passage
Obstruction → Blow out with compressed
air.

CHECKING THE TIMING CHAIN,
CRANKSHAFT SPROCKET AND TIMING
CHAIN GUIDE
The following procedure applies to all of the
camshaft sprockets and timing chain guides.
1. Check:
• Timing chain
Damage/stiffness → Replace the timing
chain and camshaft sprocket and crankshaft sprocket as a set.
2. Check:
• Crankshaft sprocket
More than 1/4 tooth wear
→ Replace
the timing chain and camshaft sprocket and
crankshaft sprocket as a set.
1/4 tooth
Correct
Timing chain roller
Crankshaft sprocket

4-74

CRANKSHAFT ASSEMBLY

ENG

3. Check:
• Timing chain guide (intake side)
Damage/wear → Replace the timing chain
guide (intake side)

INSTALLING THE PLUNGER SEAL
1. Install:
• Compression spring
• Plunger seal
• Dowel pin
Check the plunger seal smooth operation
pushing the plunger seal by your finger.

INSTALLING THE CRANKSHAFT
ASSEMBLY
1. Install:
• Crankshaft assembly
NOTE:
Install the crankshaft assembly with the crankshaft installer pot
, crankshaft installer bolt
, adapter
and spacer .
Crankshaft installer pot
90890-01274
Installing pot
YU-90058
Crankshaft installer bolt
90890-01275
Bolt
YU-90060
Spacer
90890-01288
Adapter (M10)
90890-01383
Adapter #2
YU-90062

4-75

CRANKSHAFT ASSEMBLY

ENG

CAUTION:
To avoid scratching the crankshaft and to
ease the installation procedure, lubricate
the oil seal lips with lithium-soap-based
grease and each bearing with engine oil.
NOTE:
Hold the connecting rod at top dead center
(TDC) with one hand while turning the nut of
the crankshaft installer bolt with the other. Turn
the crankshaft installer bolt until the crankshaft
assembly bottoms against the bearing.
2. Install:
• Balancer weight
To the right crank case.

4-76

TRANSMISSION

ENG

TRANSMISSION

7

3
4

5

6
1
2

Order

1
2
3
4
5
6
7

Job/Parts to remove
Removing the transmission, shift
drum assembly, and shift forks
Crankcase
Shift fork guide bar
Shift drum assembly
Shift fork-3 (R)
Shift fork-2 (C)
Shift fork-1 (L)
Main axle assembly
Drive axle assembly

Q’ty

Remarks
Remove the parts in the order listed.
Separate.
Refer to “CRANKCASE”.

1
1
1
1
1
1
1
For installation, reverse the removal
procedure.

4-77

ENG

TRANSMISSION

6
7
5
8

4
3

9

2

10

1
11
12
13
14
15

Order
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

Job/Parts to remove
Disassembling the transmission
2nd pinion gear
5th pinion gear
3rd pinion gear
Circlip/washer
4th pinion gear
Main axle
Plain washer
1st wheel gear
4th wheel gear
Circlip/washer
3rd wheel gear/collar
Claw washer 1
Claw washer 2
5th wheel gear
Circlip/washer
2nd wheel gear

Q’ty
1
1
1
1/1
1
1
1
1
1
1/1
1/1
1
1
1
1/1
1

4-78

16

Remarks
Remove the parts in the order listed.

ENG

TRANSMISSION

6
7
5
8

4
3

9

2

10

1
11
12
13
14
15

Order
17

Job/Parts to remove
Drive axle

Q’ty
1

16

Remarks
For installation, reverse the removal
procedure.

4-79

TRANSMISSION

ENG

REMOVING THE TRANSMISSION
1. Remove:
• Shift fork guide bar
• Shift drum assembly
• Shift fork 3 (R)
• Shift fork 2 (C)
• Shift fork 1 (L)
2. Remove:
• Transmission
CHECKING THE SHIFT FORKS
The following procedure applies to all of the
shift forks.
1. Check:
• Shift fork movement
(along the shift fork guide bar)
Rough movement → Replace the shift forks
and shift fork guide bar as a set.
Shift fork 3 (R)
Shift fork 2 (C)
Shift fork 1 (L)
Shift fork guide bar
Shift drum assembly
Shift fork cam follower

2. Check:
• Shift fork cam follower
• Shift fork pawl
Bends/damage/scoring/wear → Replace
the shift fork.

3. Check:
• Shift fork guide bar
Roll the shift fork guide bar on a flat surface.
Bends → Replace.

WARNING
Do not attempt to straighten a bent shift
fork guide bar.

4-80

TRANSMISSION

ENG

CHECKING THE SHIFT DRUM ASSEMBLY
1. Check:
• Shift drum groove
Damage/scratches/wear → Replace the
shift drum assembly.
• Shift drum segment
Damage/wear → Replace the shift drum
assembly.
• Shift drum bearing
Damage/pitting → Replace the shift drum
assembly.

CHECKING THE TRANSMISSION
1. Measure:
• Main axle runout
(with a centering device and dial gauge)
Out of specification → Replace the main
axle.
Main axle runout limit
0.06 mm (0.0024 in)
2. Measure:
• Drive axle runout
(with a centering device and dial gauge)
Out of specification → Replace the drive
axle.
Drive axle runout limit
0.06 mm (0.0024 in)

3. Check:
• Transmission gears
Blue discoloration/pitting/wear → Replace
the defective gear(s).
• Transmission gear dogs
Cracks/damage/rounded
edges
→
Replace the defective gear(s).

4-81

TRANSMISSION

ENG

4. Check:
• Transmission gear engagement
(each pinion gear to its respective wheel
gear)
Incorrect → Reassemble the transmission
axle assemblies.
NOTE:
When reassembling the main axle, press the
2nd pinion gear
onto it
as shown.
102.2 ~ 102.4 mm (4.02 ~ 4.03 in)

5. Check:
• Transmission gear movement
Rough movement → Replace the defective
part(s).
6. Check:
• Circlips
Bends/damage/looseness → Replace.

INSTALLING THE SHIFT FORKS AND SHIFT
DRUM ASSEMBLY
1. Install:
• Transmission
• Shift fork 1 (L)
• Shift fork 2 (C)
• Shift fork 3 (R)
• Shift drum assembly
• Shift fork guide bar
• Spacer
• Right crankcase
NOTE:
• The embossed marks on the shift forks
should face towards the left side of the engine
and be in the following sequence: “L”, “C”, “R”.
• The grooved side of the shift fork guide bar
should face towards the right side of the
engine.

2. Check:
• Shift cam operation
Unsmoothy operation → Repair.
NOTE:
Check the transmission and shift forks for
smooth operation by turning the shift cam with
your hand.

4-82

CARBURETOR
EBS00141

CARB

CARBURETOR

CARBURETOR
2 Nm (0.2 m•kg, 1.5 ft•lb)

1
3.5 Nm (0.4 m•kg, 2.6 ft•lb)

2
3
4
5

3.5 Nm (0.4 m•kg, 2.6 ft•lb)

Order

1
2
3
4
5
6
7
8
9

Job/Part
Removing a carburetor
Seat/front fender/rear fender/air filter
case
Carburetor warmer coupler
Air vent hose
Fuel hose (carburetor side)
Throttle cable cover
Throttle cable
Clamp
Clamp
Carburetor
Carburetor joint

Q’ty

1
1
1
1
1
1
2
1
1

Remarks
Remove the parts in the order listed.
Refer to “SEAT, FENDERS AND FUEL
TANK” in chapter 3.
Disconnect.
Disconnect.

Loosen.
Loosen.

Refer to “INSTALLING
THE CARBURETOR
JOINT” and “INSTALLING THE CARBURETOR”.

For installation, reverse the removal
procedure.

5-1

6
7
8

CARBURETOR

CARB

EBS00144

Order

Job/Part
Disassembling the carburetor
Drain hose
Throttle stop screw
Cover
Diaphragm spring
Piston valve
Jet needle
Cover
Spring
Coasting enricher diaphragm
Coasting enricher jet (P. A. J. 2)
Starter plunger
Carburetor warmer positive lead
Carburetor warmer
Carburetor warmer negative lead
Float chamber
Float pin

Q’ty
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

5-2

Remarks
Remove the parts in the order listed.

CARBURETOR

Order

Job/Part
Float
Needle valve seat set
Main jet
Needle jet holder
Needle jet
Pilot jet
Starter jet

Q’ty
1
1
1
1
1
1
1

CARB

Remarks

For assembly, reverse the disassembly
procedure.

5-3

CARBURETOR

CARB

EBS00148

CHECKING THE CARBURETOR
1. Check:
• carburetor body
• float chamber
Cracks/damage → Replace.
• fuel passage
Contamination → Clean as indicated.
• fuel chamber body
Contamination → Clean.
a. Wash the carburetor in a petroleum based
solvent. Do not use any caustic carburetor
cleaning solution.
b. Blow out all of the passages and jets with
compressed air.

2. Check:
• float
• float tang
Damage → Replace.

3. Check:
• valve seat
• needle valve
Contamination → Clean.
Wear/damage → Replace as a set.
NOTE:
Always replace the valve seat, needle valve
and O-ring as a set.

4. Check:
• piston valve
Scratches/wear/damage → Replace.
• piston valve diaphragm
Cracks/tears → Replace.

5-4

CARBURETOR

CARB

5. Check:
• piston valve movement
Sticks → Replace.
Insert the piston valve into the carburetor
body, and check for free movement.
6. Check:
• throttle valve movement
Sticks → Replace.

7. Check:
• cover
• diaphragm spring
Cracks/damage → Replace.

8. Check:
• coasting enricher diaphragm
• spring
Cracks/damage → Replace.

9. Check:
• jet needle
Bends/wear/damage → Replace.
• clip groove
Free play/wear → Replace.

10.Check:
• main jet
• pilot jet
• needle jet
• needle jet holder
• starter jet
• coasting enricher jet (P. A. J. 2)
Bends/wear/damage → Replace.
Blockage → Blow out the jets with compressed air.

5-5

CARBURETOR

CARB

11.Check:
• starter plunger
• starter plunger spring
Bends/cracks/damage → Replace.

EBS00150

ASSEMBLING THE CARBURETOR

CAUTION:
Before reassembling, wash all of the parts
in a clean petroleum based solvent.

1. Measure:
• float height
Out of specification → Adjust.
Float height (F.H)
13.0 mm (0.51 in)
a. Hold the carburetor in an upside down position.
b. Measure the distance from the front mating
surface of the float chamber (gasket
removed) to the top of the float.
NOTE:
The float arm should be resting on the needle
valve, but not compressing it.
c. If the float height is not within the specification, check the valve seat and needle valve.
d. If either is worn, replace the valve seat,
needle valve and O-ring as a set.
e. If both are fine, adjust the float height by
bending the float tang
on the float.
f. Recheck the float height.

5-6

CARBURETOR

CARB

INSTALLING THE CARBURETOR JOINT
1. Install:
• clamp
NOTE:
Align the projection
on the carburetor joint
with the slot
in the clamp.

2. Install:
• carburetor joint
NOTE:
Align the projection
on the cylinder head
with the slot
in the carburetor joint.

INSTALLING THE CARBURETOR
1. Install:
• carburetor
NOTE:
Align the projection
on the carburetor with
the slot
in the carburetor joint.
2. Install:
• throttle cable
• throttle cable cover
3. Adjust:
• throttle lever free play
Refer to “ADJUSTING THE THROTTLE
LEVER FREE PLAY” in chapter 3.
4. Adjust:
• engine idling speed
Refer to “ADJUSTING THE ENGINE
IDLING SPEED” in chapter 3.

5-7

FRONT AND REAR WHEELS
EBS00378

CHAS

CHASSIS

FRONT AND REAR WHEELS
FRONT WHEELS

28 Nm (2.8 m•kg, 21 ft•lb)
70 Nm (7.0 m•kg, 52 ft•lb)

28 Nm (2.8 m•kg, 21 ft•lb)

45 Nm (4.5 m•kg, 33 ft•lb)

Order

Job/Part
Removing the front wheels

Q’ty

Remarks
Remove the parts in the order listed.
The following procedure applies to both of
the front wheels.
Place the machine on a level surface.

WARNING
Securely support the machine so there
is no danger of it falling over.
1
2
3
4

Cotter pin
Axle nut
Front wheel
Brake disc guard (outer)

1
1
1
1

6-1

Refer to “INSTALLING THE WHEEL
HUBS”.
Refer to “INSTALLING THE FRONT
WHEELS”.

FRONT AND REAR WHEELS

CHAS

1

28 Nm (2.8 m•kg, 21 ft•lb)
70 Nm (7.0 m•kg, 52 ft•lb)

2
3

28 Nm (2.8 m•kg, 21 ft•lb)

4
45 Nm (4.5 m•kg, 33 ft•lb)

Order
5

Job/Part
Brake caliper assembly

Q’ty
Remarks
1 NOTE:
Do not squeeze the brake lever when the
brake caliper is off of the brake discs as
the brake pads will be forced shut.

6

Wheel hub

1

7

Brake disc

1

6-2

Refer to “INSTALLING THE WHEEL HUB
BEARINGS”.
Rear to “INSTALLING FRONT BRAKE
DISCS”.
For installation, reverse the removal
procedure.

5
6
7
8

FRONT AND REAR WHEELS

CHAS

REAR WHEELS

120 Nm (12.0 m•kg, 89 ft•lb)

45 Nm (4.5 m•kg, 33 ft•lb)

Order

Job/Part
Removing the rear wheels

Q’ty

Remarks
Remove the parts in the order listed.
Place the machine on a level surface.

WARNING
Securely support the machine so there
is no danger of it falling over.
1
2
3
4

Rear wheel
Cotter pin
Axle nut
Wheel hub

2
2
2
2

Refer to “INSTALLING THE WHEEL
HUBS”.
For installation, reverse the removal
procedure.

6-3

FRONT AND REAR WHEELS

CHAS

EBS00383

CHECKING THE WHEELS
1. Check:
• wheels
2. Measure:
• wheel runout
Over the specified limit → Replace the
wheel or check the wheel bearing play .
Wheel runout limit
Radial : 2.0 mm (0.08 in)
Lateral : 2.0 mm (0.08 in)
3. Check:
• wheel balance
Out of balance → Adjust.

WARNING
After replacing the tire, ride conservatively
to allow the tire to be properly seated in the
rim. Failure to do so may cause an accident
resulting in machine damage and possible
operator injury.

EBS00385

CHECKING THE WHEEL HUBS
1. Check:
• wheel hubs
Cracks/damage → Replace.
• splines (wheel hub)
Wear/damage → Replace the wheel hub.
Front
Rear

6-4

FRONT AND REAR WHEELS

CHAS

2. Check:
• wheel bearings
Wheel hub play/wheel turns roughly →
Replace.
a. Clean wheel hub exterior.
b. Drive bearing out by pushing spacer aside
and tapping around perimeter of bearing
inner race. Use soft metal drift punch and
“floats” between
hammer. The spacer
bearings. Remove both bearings as
described.

WARNING
Eye protection is recommended when
using striking tools.
c. To install the wheel bearings, reverse the
above sequence. Use a socket that
matches outside diameter of bearing outer
race to drive in bearing.

CAUTION:
Do not strike the center race or balls of the
bearing. Contact should be made only with
the outer race.

EBS00389

CHECKING THE BRAKE DISCS
1. Check:
• brake discs
Galling/damage → Replace.
2. Measure:
• brake disc deflection
Out of specification → Replace.
Brake disc maximum deflection
Front: 0.15 mm (0.006 in)
Rear: 0.15 mm (0.006 in)
• brake disc thickness
Out of specification → Replace.
Brake disc minimum thickness
Front: 3 mm (0.12 in)
Rear: 3.5 mm (0.14 in)

6-5

FRONT AND REAR WHEELS

CHAS

INSTALLING THE FRONT WHEEL HUB
BEARINGS
1. Install:
• bearings
NOTE:
Face the oil seal side of the bearing inward.

INSTALLING THE FRONT BRAKE DISCS
1. Install:
• brake discs
NOTE:
Install the brake disc with its spot-faced side
facing the bolt heads.

EBS00392

INSTALLING THE FRONT WHEELS
1. Install:
• brake disc guards (outer)
NOTE:
Install the brake disc guard (outer) with
punched burrs
on the wheel hub side.

2. Install:
• wheels
NOTE:
The arrow mark
on the must point in the
direction of rotation
of the wheel.

6-6

FRONT AND REAR WHEELS

CHAS

EBS00390

INSTALLING THE WHEEL HUBS
1. Install:
• front axle nuts
Front axle nut
70 Nm (7.0 m•kg, 52 ft•lb)
• rear axle nuts
Rear axle nut
120 Nm (12.0 m•kg, 89 ft•lb)
• cotter pins
NOTE:
• Do not loosen the axle nut after torquing it. If
the axle nut groove is not aligned with the cotter pin hole, align the groove with the hole by
tightening the axle nut.
• Bend the longer cotter pin up.

6-7

REAR AXLE AND REAR AXLE HUB

CHAS

EBS00382

REAR AXLE AND REAR AXLE HUB

34 Nm (3.4 m•kg, 25 ft•lb)
7 Nm (0.7 m•kg, 5.2 ft•lb)
28 Nm (2.8 m•kg, 21 ft•lb)

55 Nm (5.5 m•kg, 41 ft•lb)
140 Nm (14.0 m•kg, 103 ft•lb)

Order

1
2
3
4

Job/Part
Q’ty
Remarks
Removing the rear axle and rear axle
Remove the parts in the order listed.
hub
Rear wheels/rear wheel hubs
Refer to “FRONT AND REAR WHEELS”.
Bolt
2
Refer to “REMOVING THE REAR
Nut
1
AXLE” and “INSTALLING THE REAR
AXLE”.
Conical spring washer
1
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.

6-8

REAR AXLE AND REAR AXLE HUB

CHAS

34 Nm (3.4 m•kg, 25 ft•lb)
7 Nm (0.7 m•kg, 5.2 ft•lb)
28 Nm (2.8 m•kg, 21 ft•lb)

55 Nm (5.5 m•kg, 41 ft•lb)
140 Nm (14.0 m•kg, 103 ft•lb)

Order
5
6
7
8
9
10
11
12
13
14

Job/Part
Brake disc/brake disc bracket
Rear axle
Driven sprocket/sprocket bracket
Circlip
Brake caliper bracket
Collar
Rear axle hub
Bearing/oil seal
Spacer
Dust cover

Q’ty
Remarks
1/1
1 Refer to “REMOVING THE REAR AXLE”.
1/1 Refer to “INSTALLING THE DRIVEN
SPROCKET”.
1
1
1
1
2/2
1
1
For installation, reverse the removal
procedure.

6-9

REAR AXLE AND REAR AXLE HUB

CHAS

EBS00393

REMOVING THE REAR AXLE
1. Place the machine on a level surface.
2. Loosen:
• bolts
3. Remove:
• nut
NOTE:
• Apply the brake pedal so that the rear axle
does not turn, when loosening the nut.
• Use the PTT wrench 46 or axle nut wrench
(46 mm) .
PTT wrench 46
90890-06588
Axle nut wrench (46 mm)
YM-37134
4. Elevate the rear wheels by placing the suitable stand under the frame.
5. Remove:
• rear wheels
• wheel hubs
• nuts
• washers

6. Remove:
• rear axle

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
on the axle
end and tap it with a soft hammer, then
pull out the rear axle to the right.

6-10

REAR AXLE AND REAR AXLE HUB

CHAS

EBS00395

CHECKING THE REAR AXLE
1. Check:
• rear axle runout
Out of specification → Replace.

WARNING
Do not attempt to straighten a bent axle.
Rear axle runout limit
1.5 mm (0.06 in)
CHECKING THE DRIVEN SPROCKET
1. Check:
• driven sprocket
Refer to “REAR SHOCK ABSORBER,
SWINGARM AND DRIVE CHAIN”.

CHECKING THE BRAKE DISC
1. Check:
• brake disc
Refer to “FRONT AND REAR WHEELS”.

INSTALLING THE DRIVEN SPROCKET
1. Install:
• driven sprocket
NOTE:
Make sure that the blunt-edged corner
the driven sprocket is facing outward.

of

EBS00397

INSTALLING THE REAR AXLE
1. Install:
• conical spring washer
NOTE:
Install the conical spring washer with the convex side of the washer facing inward as shown.

6-11

REAR AXLE AND REAR AXLE HUB

CHAS

2. Tighten:
• nut
a. Tighten the nut with PTT wrench 46 or rear
axle nut wrench
to specification while
holding the rear axle.
140 Nm (14.0 m•kg, 103 ft•lb)

PTT wrench 46
90890-06588
Axle nut wrench (46 mm)
YM-37134
b. Tighten bolts

.
7 Nm (0.7 m•kg, 5.2 ft•lb)

6-12

FRONT AND REAR BRAKES

CHAS

EBS00400

FRONT AND REAR BRAKES
FRONT BRAKE PADS

2.5 Nm (0.25 m•kg, 1.8 ft•lb)

17 Nm (1.7 m•kg, 13 ft•lb)

28 Nm (2.8 m•kg, 21 ft•lb)

Order

1
2
3
4

Job/Part
Removing the front brake pads

Front wheel
Bolt
Brake pad retaining bolt
Brake pad
Brake pad spring

Q’ty

1
1
2
1

Remarks
Remove the parts in the order listed.
The following procedure applies to both of
the front brake calipers.
Refer to “FRONT AND REAR WHEELS”.
Refer to “REPLACING THE FRONT
BRAKE PADS”.
For installation, reverse the removal
procedure.

6-13

FRONT AND REAR BRAKES

CHAS

EBS00401

REAR BRAKE PADS

17 Nm (1.7 m•kg, 13 ft•lb)

34 Nm (3.4 m•kg, 25 ft•lb)

Order
1
2
3
4

Job/Part
Removing the rear brake pads
Brake pad retaining bolt
Lock washer
Brake pad
Brake pad spring

Q’ty
2
1
2
1

Remarks
Remove the parts in the order listed.
Refer to “REPLACING THE REAR
BRAKE PADS”.
For installation, reverse the removal
procedure.

6-14

FRONT AND REAR BRAKES

CHAS

EBS00402

CAUTION:
Disc brake components rarely require disassembly.
DO NOT:
• disassemble components unless absolutely necessary;
• use solvents on internal brake components;
• use spent brake fluid for cleaning; (use
only clean brake fluid)
• allow brake fluid to come in contact with
the eyes, as this may cause eye injury;
• splash brake fluid onto painted surfaces
or plastic parts, as this may cause damage;
• disconnect any hydraulic connection, as
this would require the entire brake system
to be disassembled, drained, cleaned,
properly filled and bled after reassembly.

EBS00404

REPLACING THE FRONT BRAKE PADS
The following procedure applies to both of the
front brake calipers.
NOTE:
It is not necessary to disassemble the brake
calipers and brake hoses to replace the brake
pads.

1. Remove:
• brake pads
Wear limit

NOTE:
Replace the brake pads as a set if either is
found to be worn to the wear limit.

6-15

CHAS

FRONT AND REAR BRAKES

2. Install:
• brake pads
• brake pad spring
NOTE:
Always install new brake pads and brake pad
spring as a set.

a. Connect a suitable hose
tightly to the
brake caliper bleed screw . Put the other
end of this hose into an open container.
b. Loosen the brake caliper bleed screw and,
using a finger, push the caliper piston into
the brake caliper.
c. Tighten the brake caliper bleed screw.
5 Nm (0.5 m•kg, 3.7 ft•lb)

d. Install new brake pads and a new brake
pad spring.
3. Install:
• brake pad retaining bolt
• bolt
Brake pad retaining bolt
17 Nm (1.7 m•kg, 13 ft•lb)
Bolt
3 Nm (0.3 m•kg, 2 ft•lb)
4. Install:
• brake caliper
• brake caliper mounting bolts
Brake caliper mounting bolt
28 Nm (2.8 m•kg, 21 ft•lb)
5. Check:
• brake fluid level
Refer to “CHECKING THE BRAKE FLUID
LEVEL” in chapter 3.
6. Check:
• brake lever operation
Soft or spongy feeling → Bleed the brake
system.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.

6-16

FRONT AND REAR BRAKES

CHAS

EBS00405

REPLACING THE REAR BRAKE PADS
NOTE:
It is not necessary to disassemble the brake
caliper and brake hose to replace the brake
pads.

1. Remove:
• brake pads
wear limit

NOTE:
Replace the brake pads as a set if either is
found to be worn to the wear limit.
2. Install:
• brake pads
• brake pad spring
NOTE:
Always install new brake pads and brake pad
spring as a set.
a. Connect a suitable hose
tightly to the
brake caliper bleed screw . Put the other
end of this hose into an open container.
b. Loosen the brake caliper bleed screw and,
using a finger, push the caliper piston into
the brake caliper.
c. Tighten the brake caliper bleed screw.
5 Nm (0.5 m•kg, 3.7 ft•lb)

d. Install a new brake pad spring and new
brake pads.
3. Install:
• brake pad retaining bolts
(Bend the lock washer tabs along a flat side
of the bolts)
• brake caliper
• brake caliper mounting bolts
Brake pad retaining bolt
17 Nm (1.7 m•kg, 13 ft•lb)
Brake caliper mounting bolt
34 Nm (3.4 m•kg, 25 ft•lb)
4. Check:
• brake fluid level
Refer to “CHECKING THE BRAKE FLUID
LEVEL” in chapter 3.

6-17

FRONT AND REAR BRAKES

CHAS

5. Check:
• brake lever or brake pedal operation
Soft or spongy feeling → Bleed the brake
system.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.

6-18

FRONT AND REAR BRAKES

CHAS

EBS00407

FRONT BRAKE MASTER CYLINDER

7 Nm (0.7 m•kg, 5.2 ft•lb)

6 Nm (0.6 m•kg, 4.4 ft•lb)

27 Nm (2.7 m•kg, 20 ft•lb)

Order

1
2
3
4
5
6
7
8
9
10

Job/Part
Removing the front brake master
cylinder
Brake fluid

Brake fluid reservoir cap
Brake fluid reservoir diaphragm plate
Brake fluid reservoir diaphragm
Front brake light switch
Brake lever
Union bolt
Copper washer
Brake hose
Brake master cylinder bracket
Brake master cylinder

Q’ty

Remarks
Remove the parts in the order listed.
Drain.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.

1
1
1
1
1
1
2
1
1
1

Disconnect.

Refer to “INSTALLING
THE FRONT BRAKE
MASTER CYLINDER”.

For installation, reverse the removal
procedure.

6-19

FRONT AND REAR BRAKES

CHAS

EBS00409

Order

Job/Part
Disassembling the front brake
master cylinder
Dust boot
Circlip
Brake master cylinder kit

Q’ty

1
1
1

Remarks
Remove the parts in the order listed.
Refer to “ASSEMBLING THE FRONT
BRAKE MASTER CYLINDER”.
For assembly, reverse the disassembly
procedure.

6-20

FRONT AND REAR BRAKES

CHAS

EBS00410

REAR BRAKE MASTER CYLINDER
7 Nm (0.7 m•kg, 5.2 ft•lb)

31 Nm (3.1 m•kg, 23 ft•lb)

20 Nm (2.0 m•kg, 15 ft•lb)

73 Nm (7.3 m•kg, 54 ft•lb)

Order

Job/Part
Removing the rear brake master
cylinder
Right foot protector

Q’ty

Refer to “SEAT, FENDERS AND FUEL
TANK” in chapter 3.
Drain.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.

Brake fluid

1
2
3
4
5
6

Remarks
Remove the parts in the order listed.

Brake fluid reservoir cover
Brake fluid reservoir cap
Brake fluid reservoir diaphragm holder
Brake fluid reservoir diaphragm
Brake fluid reservoir
Brake fluid reservoir hose

1
1
1
1
1
1

6-21

FRONT AND REAR BRAKES

CHAS

7 Nm (0.7 m•kg, 5.2 ft•lb)

31 Nm (3.1 m•kg, 23 ft•lb)

20 Nm (2.0 m•kg, 15 ft•lb)

73 Nm (7.3 m•kg, 54 ft•lb)

Order
7
8
9
10
11
12
13

Job/Part
Union bolt
Copper washer
Brake hose
Brake master cylinder
Rear brake light switch
Right footrest
Brake pedal/spring

Q’ty
Remarks
1
Refer to “INSTALLING
2
THE REAR BRAKE
1 Disconnect.
MASTER CYLINDER”.
1
1
1
1/1
For installation, reverse the removal
procedure.

6-22

FRONT AND REAR BRAKES

CHAS

EBS00411

17 Nm (1.7 m•kg, 13 ft•lb)

Order

Job/Part
Disassembling the rear brake
master cylinder
Hose joint
Brake master cylinder kit
Brake master cylinder

Q’ty

1
1
1

6-23

Remarks
Remove the parts in the order listed.

Refer to “ASSEMBLING THE REAR
BRAKE MASTER CYLINDER”.
For assembly, reverse the disassembly
procedure.

FRONT AND REAR BRAKES

CHAS

EBS00413

CHECKING THE MASTER CYLINDERS
1. Check:
• brake master cylinder
Wear/scratches → Replace the brake master cylinder assembly.
• brake master cylinder body
Cracks/damage → Replace.
• brake fluid delivery passage
(brake master cylinder body)
Blockage → Blow out with compressed air.
Front
Rear

2. Check:
• brake master cylinder kit
Scratches/wear/damage → Replace as a
set.
Front
Rear

3. Check:
• front brake master cylinder reservoir
• front brake master cylinder reservoir diaphragm
Cracks/damage → Replace.

4. Check:
• rear brake fluid reservoir
• rear brake fluid reservoir diaphragm
Cracks/damage → Replace.

6-24

FRONT AND REAR BRAKES

CHAS

EBS00415

ASSEMBLING THE FRONT BRAKE
MASTER CYLINDER

WARNING
• All internal brake components should be
cleaned and lubricated with new brake
fluid only before installation.
Recommended brake fluid
DOT 4
• Whenever a master cylinder is disassembled, replace the piston seals and dust
seals.

EBS00416

ASSEMBLING THE REAR BRAKE MASTER
CYLINDER

WARNING
• All internal brake components should be
cleaned and lubricated with new brake
fluid only before installation.
Recommended brake fluid
DOT 4
• Whenever a master cylinder is disassembled, replace the piston seals and dust
seals.
1. Install:
• brake master cylinder kit
• nut
• joint
NOTE:
Turn the adjusting bolt
until the clearance
is within the specified limits when install the
joint .
Clearance
2.2 ~ 3.2 mm (0.09 ~ 0.13 in)

6-25

FRONT AND REAR BRAKES

CHAS

2. Tighten:
• nut
Nut
17 Nm (1.7 m•kg, 13 ft•lb)

EBS00418

INSTALLING THE FRONT BRAKE MASTER
CYLINDER
1. Install:
• brake master cylinder
Brake master cylinder holder bolt
7 Nm (0.7 m•kg, 5.1 ft•lb)
NOTE:
• The “UP” mark on the brake master cylinder
bracket should face up.
• Install the brake master cylinder so that the
gaps between the brake master cylinder and
the brake master cylinder bracket are equal.

2. Install:
• copper washers
• brake hose
• union bolt
Union bolt
27 Nm (2.7 m•kg, 20 ft•lb)
NOTE:
• Tighten the union bolt while holding the brake
hose as shown.
• Turn the handlebar to the left and to the right
to check that the brake hose does not touch
other parts (throttle cable, wire harness,
leads, etc.). Correct if necessary.

WARNING
Proper brake hose routing is essential to
insure safe machine operation. Refer to
“CABLE ROUTING” in chapter 2.

6-26

FRONT AND REAR BRAKES

CHAS

3. Fill:
• brake fluid reservoir
Recommended brake fluid
DOT 4

CAUTION:
Brake fluid may damage painted surfaces
or plastic parts. Always clean up spilled
brake fluid immediately.

WARNING
• Use only the designated quality brake
fluid: other brake fluids may deteriorate
the rubber seals, causing leakage and
poor brake performance.
• Refill with the same type of brake fluid:
mixing brake fluids may result in a harmful reaction and lead to poor brake performance.
• Be careful that water does not enter the
brake master cylinder when refilling.
Water will significantly lower the boiling
point of the brake fluid and may result in
vapor lock.
4. Air bleed:
• brake system
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.
5. Check:
• brake fluid level
Brake fluid level is under the “LOWER” level
line → Add the recommended brake fluid to
the proper level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” in chapter 3.

6-27

FRONT AND REAR BRAKES

CHAS

EBS00419

INSTALLING THE REAR BRAKE MASTER
CYLINDER
1. Install:
• copper washers
• brake hose
• union bolt
Union bolt
31 Nm (3.1 m•kg, 23 ft•lb)

CAUTION:
When installing the brake hose onto the
brake master cylinder, make sure the brake
pipe
touches the projection
as
shown.

WARNING
Proper brake hose routing is essential to
insure safe machine operation. Refer to
“CABLE ROUTING” in chapter 2.

2. Install:
• brake fluid reservoir hose
NOTE:
Install the brake fluid reservoir hose with the
white paint mark
facing up as shown.
3. Fill:
• brake fluid reservoir
Recommended brake fluid
DOT 4

CAUTION:
Brake fluid may damage painted surfaces
or plastic parts. Always clean up spilled
brake fluid immediately.

6-28

FRONT AND REAR BRAKES

CHAS

WARNING
• Use only the designated quality brake
fluid: other brake fluids may deteriorate
the rubber seals, causing leakage and
poor brake performance.
• Refill with the same type of brake fluid:
mixing brake fluids may result in a harmful chemical reaction and lead to poor
brake performance.
• Be careful that water does not enter the
brake master cylinder when refilling.
Water will significantly lower the boiling
point of the brake fluid and may result in
vapor lock.
4. Air bleed:
• brake system
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.
5. Check:
• brake fluid level
Brake fluid level is under the “LOWER” level
line → Add the recommended brake fluid to
the proper level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” in chapter 3.

6-29

FRONT AND REAR BRAKES

CHAS

EBS00421

FRONT BRAKE CALIPERS

17 Nm (1.7 m•kg, 13 ft•lb)

2.5 Nm (0.25 m•kg, 1.8 ft•lb)

28 Nm (2.8 m•kg, 21 ft•lb)

27 Nm (2.7 m•kg, 20 ft•lb)

Order

Job/Part
Removing the front brake calipers

Q’ty

Brake fluid

1
2
3
4
5
6

Front wheel
Union bolt
Copper washer
Brake hose
Bolt
Brake pad retaining bolt
Brake caliper assembly

1
2
1
1
2
1

Remarks
Remove the parts in the order listed.
The following procedure applies to both of
the front brake calipers.
Drain.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.
Refer to “FRONT AND REAR WHEELS”.

Disconnect.
Loosen.

Refer to “INSTALLING
THE FRONT BRAKE
CALIPERS”.

For installation, reverse the removal
procedure.

6-30

FRONT AND REAR BRAKES

CHAS

EBS00423

5 Nm (0.5 m•kg, 3.7 ft•lb)

17 Nm (1.7 m•kg, 13 ft•lb)

2.5 Nm (0.25 m•kg, 1.8 ft•lb)

Order

Job/Part
Disassembling the front brake
calipers

Q’ty

Remarks
Remove the parts in the order listed.
The following procedure applies to both of
the front brake calipers.

Bolt
Brake pad retaining bolt
Brake pad
Brake pad spring
Caliper bracket
Caliper piston
Dust seal
Caliper piston seal

1
1
2
1
1
1
1
1

Bleed screw

1

Refer to “DISASSEMBLING THE
FRONT AND REAR BRAKE CALIPERS”
and “ASSEMBLING THE FRONT
BRAKE CALIPERS”.
For assembly, reverse the disassembly
procedure.

6-31

FRONT AND REAR BRAKES

CHAS

EBS00424

REAR BRAKE CALIPER
31 Nm (3.1 m•kg, 23 ft•lb)

34 Nm (3.4 m•kg, 25 ft•lb)

Order

Job/Part
Removing the rear brake caliper
Brake fluid

Q’ty

1

Parking brake cable

1

2
3
4
5

Union bolt
Copper washer
Brake hose
Brake caliper assembly

1
2
1
1

Remarks
Remove the parts in the order listed.
Drain.
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.
Disconnect.
Refer to “REMOVING THE PARKING
BRAKE CABLE”.

Disconnect.

Refer to “INSTALLING
THE REAR BRAKE
CALIPER”.

For installation, reverse the removal
procedure.

6-32

FRONT AND REAR BRAKES

CHAS

EBS00425

17 Nm (1.7 m•kg, 13 ft•lb)

5 Nm (0.5 m•kg, 3.7 ft•lb)
17 Nm (1.7 m•kg, 13 ft•lb)
15 Nm (1.5 m•kg, 11 ft•lb)

Order

Job/Part
Q’ty
Remarks
Disassembling the rear brake caliper
Remove the parts in the order listed.
Adjusting bolt
1
Locknut
1
Parking brake arm
1
Brake pad retain bolt
2
Lock washer
1
Brake pad
2
Brake pad spring
1
Retaining bolt
1
Caliper bracket
1
Refer to “DISASSEMBLING THE
Brake caliper piston
1
FRONT AND REAR BRAKE
Dust seal
1
CALIPERS” and “ASSEMBLING THE
Caliper piston seal
1
REAR BRAKE CALIPER”.
Bleed screw
1
For assembly, reverse the disassembly
procedure.

6-33

FRONT AND REAR BRAKES

CHAS

REMOVING THE PARKING BRAKE CABLE
1. Loosen:
• nut
• adjusting bolt
2. Disconnect:
• parking brake cable
(from parking brake lever)
3. Disconnect:
• parking brake cable
(from rear brake)
EBS00427

DISASSEMBLING THE FRONT AND REAR
BRAKE CALIPERS
1. Remove:
• brake caliper piston
• caliper dust seal
• caliper piston seal
Front
Rear

a. Blow compressed air into the hose joint
opening to force out the caliper piston from
the brake caliper body.

WARNING
• Never try to pry out the caliper piston.
• Cover the caliper piston with a rag. Be
careful not to get injured when the piston
is expelled from the caliper cylinder.
b. Remove the caliper piston seal.

6-34

FRONT AND REAR BRAKES

CHAS

EBS00429

CHECKING THE FRONT AND REAR BRAKE
CALIPERS
Recommended brake component
replacement schedule
Brake pads
As required
Piston seals, dust
Every two years
seals
Brake hoses
Every four years
Replace when
Brake fluid
brakes are
disassembled.

WARNING
All internal brake components should be
cleaned in new brake fluid only. Do not use
solvents as they will cause seals to swell
and distort.

1. Check:
• brake caliper piston
Scratches/rust/wear → Replace the brake
caliper assembly.
• brake caliper cylinder
Wear/scratches → Replace the brake caliper assembly.
• brake caliper body
Cracks/damage → Replace.
• brake fluid delivery passage
(brake caliper body)
Blockage → Blow out with compressed air.

WARNING
Replace the caliper piston seal and dust
seal whenever the brake caliper is disassembled.
Front
Rear

6-35

FRONT AND REAR BRAKES

CHAS

EBS00431

ASSEMBLING THE FRONT BRAKE
CALIPERS
The following procedure applies to both of the
front brake calipers.

WARNING
• All internal brake components should be
cleaned and lubricated with new brake
fluid only before installation.
Recommended brake fluid
DOT 4
• Replace the caliper piston seal whenever
a brake caliper is disassembled.
1. Install:
• caliper piston seal
• caliper dust seal
2. Install:
• brake caliper piston

EBS00432

ASSEMBLING THE REAR BRAKE CALIPER

WARNING
• All internal brake components should be
cleaned and lubricated with new brake
fluid only before installation.
Recommended brake fluid
DOT 4
• Replace the caliper piston seal whenever
a brake caliper is disassembled.
1. Install:
• O-ring
• caliper piston seal
• caliper dust seal

6-36

FRONT AND REAR BRAKES

CHAS

2. Install:
• brake caliper piston

3. Install:
• lock washer
• brake pad retaining bolts
Brake pad retaining bolt
17 Nm (1.7 m•kg, 13 ft•lb)
4. Bend the lock washer tabs along a flat side
of the bolts.

5. Install:
• parking brake arm
6. Measure:
• parking brake arm to parking brake bracket
distance
Out of specification → Adjust.
Parking brake arm to parking
brake bracket distance
73.3 mm (2.89 in)

6-37

FRONT AND REAR BRAKES

CHAS

EBS00434

INSTALLING THE FRONT BRAKE
CALIPERS
The following procedure applies to both of the
front brake calipers.
1. Install:
• brake caliper assembly
• brake caliper mounting bolts
Brake caliper mounting bolt
28 Nm (2.8 m•kg, 21 ft•lb)
• brake hose
• copper washers
• union bolt
Union bolt
27 Nm (2.7 m•kg, 20 ft•lb)

CAUTION:
When installing the brake hose on the
brake caliper, make sure that the brake pipe
touches the projection
on the brake
caliper.

WARNING
Proper brake hose routing is essential to
insure safe machine operation. Refer to
“CABLE ROUTING” in chapter 2.
2. Fill:
• brake reservoir
Recommended brake fluid
DOT 4

CAUTION:
Brake fluid may damage painted surfaces
or plastic parts. Always clean up spilled
brake fluid immediately.

6-38

FRONT AND REAR BRAKES

CHAS

WARNING
• Use only the designated quality brake
fluid: other brake fluids may deteriorate
the rubber seals, causing leakage and
poor brake performance.
• Refill with the same type of brake fluid:
mixing brake fluids may result in a harmful chemical reaction and lead to poor
brake performance.
• Be careful that water does not enter the
master cylinder when refilling. Water will
significantly lower the boiling point of the
brake fluid and may result in vapor lock.
3. Air bleed:
• brake system
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.
4. Check:
• brake fluid level
Brake fluid level is below the “LOWER” level
line → Add the recommended brake fluid to
the proper level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” in chapter 3.

6-39

FRONT AND REAR BRAKES

CHAS

EBS00436

INSTALLING THE REAR BRAKE CALIPER
1. Install:
• brake caliper assembly
• brake caliper mounting bolts
Brake caliper mounting bolt
34 Nm (3.4 m•kg, 25 ft•lb)
• brake hose
• copper washers
• union bolt
Union bolt
31 Nm (3.1 m•kg, 23 ft•lb)

CAUTION:
When installing the brake hose on the
brake caliper, make sure that the brake pipe
touches the projection
on the brake caliper.

WARNING
Proper brake hose routing is essential to
insure safe machine operation. Refer to
“CABLE ROUTING” in chapter 2.
2. Fill:
• brake reservoir
Recommended brake fluid
DOT 4

CAUTION:
Brake fluid may damage painted surfaces
or plastic parts. Always clean up spilled
brake fluid immediately.

6-40

FRONT AND REAR BRAKES

CHAS

WARNING
• Use only the designated quality brake
fluid: other brake fluids may deteriorate
the rubber seals, causing leakage and
poor brake performance.
• Refill with the same type of brake fluid:
mixing brake fluids may result in a harmful chemical reaction and lead to poor
brake performance.
• Be careful that water does not enter the
master cylinder when refilling. Water will
significantly lower the boiling point of the
brake fluid and may result in vapor lock.
3. Air bleed:
• brake system
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in chapter 3.
4. Check:
• brake fluid level
Brake fluid level is below the “LOWER” level
line → Add the recommended brake fluid to
the proper level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” in chapter 3.
5. Adjust:
• parking brake cable end length
Refer to “ADJUSTING THE PARKING
BRAKE” in chapter 3.

6-41

STEERING SYSTEM

CHAS

EBS00444

STEERING SYSTEM
HANDLEBAR
7 Nm (0.7 m•kg, 5.2 ft•lb)
20 Nm (2.0 m•kg, 15 ft•lb)

4 Nm (0.4 m•kg, 3.0 ft•lb)

4 Nm (0.4 m•kg, 3.0 ft•lb)
7 Nm (0.7 m•kg, 5.2 ft•lb)

Order
1
2
3
4
5
6
7

Job/Part
Removing the handlebar
Handlebar protecter
Band
Front brake light switch
Brake master cylinder/bracket
Throttle lever assembly/bracket
Spacer
Clutch switch

8
9
10

Parking brake lever
Clutch lever/bracket
Handlebar switch

Q’ty

Remarks
Remove the parts in the order listed.

1
3
1
1/1
Refer to “INSTALLING THE BRAKE
1/1
MASTER CYLINDER”.
1
1 Refer to “REMOVING THE CLUTCH
SWITCH”.
1
1/1 Refer to “INSTALLING THE CLUTCH
LEVER”.
1

6-42

STEERING SYSTEM

CHAS

7 Nm (0.7 m•kg, 5.2 ft•lb)
20 Nm (2.0 m•kg, 15 ft•lb)

4 Nm (0.4 m•kg, 3.0 ft•lb)

4 Nm (0.4 m•kg, 3.0 ft•lb)
7 Nm (0.7 m•kg, 5.2 ft•lb)

Order

Job/Part

11

Handlebar grip

12
13

Handlebar holder
Handlebar

Q’ty
Remarks
2 Refer to “REMOVING THE HANDLEBAR
GRIPS” and “INSTALLING THE
HANDLEBAR GRIPS”.
2
Refer to “INSTALLING THE
1
HANDLEBAR”.
For installation, reverse the removal
procedure.

6-43

STEERING SYSTEM

CHAS

EBS00446

REMOVING THE CLUTCH SWITCH
1. Remove:
• clutch switch
NOTE:
Push the fastener when removing the clutch
switch out of the clutch lever holder.

EBS00447

REMOVING THE HANDLEBAR GRIPS
1. Remove:
• handlebar grips
NOTE:
Blow compressed air between the handlebar
and handlebar grip, and gradually push the
grip off the handlebar.

EBS00448

CHECKING THE HANDLEBAR
1. Check:
• handlebar
Bends/cracks/damage → Replace.

WARNING
Do not attempt to straighten a bent handlebar as this may dangerously weaken the
handlebar.

6-44

STEERING SYSTEM

CHAS

EBS00449

INSTALLING THE HANDLEBAR
1. Install:
• handlebar
• handlebar holders
Handleber holder
20 Nm (2.0 m•kg, 15 ft•lb)
NOTE:
• Install the handlebar horizontally shown in the
illustration.
• The upper handlebar holder should be
forward
installed with the punched mark
.

CAUTION:
First tighten the bolt
on the front side of
the handlebar holder, and then tighten the
bolt
on the rear side.

EBS00450

INSTALLING THE HANDLEBAR GRIPS
1. Install:
• handlebar grips
NOTE:
• Before applying the adhesive, wipe off grease
with a lacor oil on the handlebar surface
quer thinner.
• Install the handlebar grips so that the “L”
arrow on the left grip and “R” arrow on the
right grip are placed vertically.

6-45

STEERING SYSTEM

CHAS

EBS00452

INSTALLING THE CLUTCH LEVER
1. Install:
• handlebar switch
• clutch lever
• clutch lever bracket
NOTE:
• Install the clutch lever bracket as shown.
• Install the clutch lever
at 10 degrees angle
as shown.
53 ~ 54 mm (2.09 ~ 2.13 in)

EBS00453

INSTALLING THE BRAKE MASTER
CYLINDER
1. Install:
• throttle lever assembly
• spacer
• brake master cylinder
Brake master cylinder bracket
7 Nm (0.7 m•kg, 5.2 ft•lb)
NOTE:
• Engage the indentations
in the spacer with
on the throttle lever assembly
the lobes
and brake master cylinder.
• The “UP” mark on the brake master cylinder
bracket should face up.
• Install the brake lever
at 10 degrees angle
as shown.

6-46

STEERING SYSTEM

CHAS

EBS00454

STEERING STEM
23 Nm (2.3 m•kg, 17 ft•lb)

25 Nm (2.5 m•kg, 18 ft•lb)
35 Nm (3.5 m•kg, 26 ft•lb)

Order

Job/Part
Removing the steering stem
Front fender

Q’ty

1

Lock washer

1

2
3
4
5
6
7

Bracket
Steering stem bushing
Spacer
Oil seal
Steering stem
Bushing

1
2
2
2
1
2

6-47

Remarks
Remove the parts in the order listed.
Refer to “SEAT, FENDERS AND FUEL
TANK” in chapter 3.
Refer to “INSTALLING THE LOCK
WASHER”.

STEERING SYSTEM

CHAS

EBS00456

CHECKING THE STEERING STEM
1. Check:
• steering stem
Bends/damage → Replace.

WARNING
Do not attempt to straighten a bent stem;
this may dangerously weaken the stem.

2. Check:
• oil seals
• steering stem bushings
Wear/damage → Replace.

3. Check
• O-rings
• bushings
Wear/damage → Replace.

INSTALLING THE STEERING STEM
1. Install:
• steering stem
NOTE:
Pass the throttle cable through the cable guide.
Refer to “CABLE ROUTING” in chapter 2.

EBS00459

INSTALLING THE LOCK WASHER
1. Install:
• lock washer
• bolts
Bolt
23 Nm (2.3 m•kg, 17 ft•lb)
2. Bend the lock washer tab along a flat side
of the bolt.

6-48

STEERING SYSTEM

CHAS

EBS00460

TIE-RODS AND STEERING KNUCKLES
31 Nm (3.1 m•kg, 23 ft•lb)

45 Nm (4.5 m•kg, 33 ft•lb)
25 Nm (2.5 m•kg, 18 ft•lb)

45 Nm (4.5 m•kg, 33 ft•lb)

25 Nm (2.5 m•kg, 18 ft•lb)

48 Nm (4.8 m•kg, 35 ft•lb)
25 Nm (2.5 m•kg, 18 ft•lb)

Order

1
2
3
4
5
6

Job/Part
Removing the tie-rods and steering
knuckles

Front wheel/brake disc
Front brake caliper
Brake disc guard (inner)
Tie-rod
Front bumper
Lower front arm
Upper front arm
Steering knuckle

Q’ty

Remarks
Remove the parts in the order listed.
The following procedure applies to both of
the tie-rods and steering knuckles.
Refer to “FRONT AND REAR WHEELS”.
Refer to “FRONT AND REAR BRAKES”.

1
1
1
1
1
1

6-49

Refer to “INSTALLING THE TIE-RODS”.

Refer to “REMOVING THE STEERING
KNUCKLES”.
For installation, reverse the removal
procedure.

STEERING SYSTEM

CHAS

EBS00461

REMOVING THE STEERING KNUCKLES
1. Remove:
• steering knuckles
NOTE:
Use a general puller to separate the ball joint
and steering knuckle.

EBS00462

CHECKING THE TIE-RODS
1. Check:
• tie-rod free play and movement
Free play → Replace the tie-rod end.
Turns roughly → Replace the tie-rod end.
2. Check:
• tie-rods
Bends/damage → Replace.

EBS00464

CHECKING THE STEERING KNUCKLES
1. Check:
• steering knuckles
Damage/pitting → Replace.

EBS00465

INSTALLING THE TIE-RODS
1. Install:
• tie-rods (left and right)
Ball joint nut
25 Nm (2.5 m•kg, 18 ft•lb)
NOTE:
The tie-rod side which must be installed on the
outside has grooves .
2. Adjust:
• toe-in
Refer to “ADJUSTING THE TOE-IN” in
chapter 3.

6-50

FRONT ARMS AND FRONT SHOCK ABSORBER
ASSEMBLIES

CHAS

EBS00468

FRONT ARMS AND FRONT SHOCK ABSORBER ASSEMBLIES
45 Nm (4.5 m•kg, 33 ft•lb)

31 Nm (3.1 m•kg, 23 ft•lb)
48 Nm (4.8 m•kg, 35 ft•lb)

45 Nm (4.5 m•kg, 33 ft•lb)

48 Nm (4.8 m•kg, 35 ft•lb)
25 Nm (2.5 m•kg, 18 ft•lb)

Order

1
2
3
4

5
6
7

Job/Part
Removing the front arms and front
shock absorber assemblies

Front wheel/brake disc
Front brake caliper
Front bumper
Brake disc guard (inner)
Tie-rod
Lower front arm
Upper front arm
Front shock absorber
Steering knuckle

Q’ty

25 Nm (2.5 m•kg, 18 ft•lb)

Remarks
Remove the parts in the order listed.
The following procedure applies to both of
the front arms and front shock absorber
assemblies.
Refer to “FRONT AND REAR WHEELS”.
Refer to “FRONT AND REAR BRAKES”.

1
1
1
1
1
1
1

6-51

Disconnect.
Refer to “REMOVING THE FRONT ARMS”
and “INSTALLING THE FRONT ARMS”.

FRONT ARMS AND FRONT SHOCK ABSORBER
ASSEMBLIES

CHAS

45 Nm (4.5 m•kg, 33 ft•lb)

31 Nm (3.1 m•kg, 23 ft•lb)
48 Nm (4.8 m•kg, 35 ft•lb)

45 Nm (4.5 m•kg, 33 ft•lb)

48 Nm (4.8 m•kg, 35 ft•lb)
25 Nm (2.5 m•kg, 18 ft•lb)

Order
8
9
10
11

Job/Part
Dust cover
Spacer
Spacer
Bushing

Q’ty
6
1
2
6

25 Nm (2.5 m•kg, 18 ft•lb)

Remarks

For installation, reverse the removal
procedure.

6-52

FRONT ARMS AND FRONT SHOCK ABSORBER
ASSEMBLIES

CHAS

EBS00469

REMOVING THE FRONT ARMS
1. Check:
• front arm free play
a. Check the front arm side play
by moving
it from side to side.
If side play is noticeable, check the bushings.
b. Check the front arm vertical movement
by moving it up and down.
If the vertical movement is tight or rough, or
if there is binding, check the bushings.
2. Remove:
• front arm

EBS00470

CHECKING THE FRONT ARMS
1. Check:
• front arms
Bends/damage → Replace.
2. Check:
• bushings
Wear/damage → Replace.

EBS00488

CHECKING THE FRONT SHOCK
ABSORBERS
The following procedure applies to both
front shock absorber assemblies.
1. Check:
• shock absorber
Oil leaks → Replace the front
absorber assembly.
• shock absorber rod
Bends/damage → Replace the front
absorber assembly.
• spring
Fatigue → Replace the front
absorber assembly.
Move the spring up and down.

6-53

of the

shock

shock

shock

FRONT ARMS AND FRONT SHOCK ABSORBER
ASSEMBLIES

CHAS

EBS00472

CHECKING THE BALL JOINTS
The following procedure applies to both of the
front arm ball joints.
1. Check:
• ball joint
Damage/pitting → Replace the front arm.
Free play → Replace the front arm.
Turns roughly → Replace the front arm.

EBS00473

INSTALLING THE FRONT ARMS
The following procedure applies to both of the
front arms.
1. Install:
• upper front arm
• lower front arm
Front arm (upper, lower)
45 Nm (4.5 m•kg, 33 ft•lb)
NOTE:
• Be sure to position the bolts (upper and
lower) so that the bolt head faces forward.
• Apply lithium-soap-based grease to the
grease nipple .

6-54

REAR SHOCK ABSORBER, SWINGARM AND
DRIVE CHAIN

CHAS

REAR SHOCK ABSORBER, SWINGARM AND DRIVE CHAIN
55 Nm (5.5 m•kg, 41 ft•lb)

23 Nm (2.3 m•kg, 17 ft•lb)

100 Nm (10.0 m•kg, 74 ft•lb)
110 Nm (11.0 m•kg, 81 ft•lb)
55 Nm (5.5 m•kg, 41 ft•lb)

Order

Job/Part
Removing the rear shock absorber,
swingarm and drive chain
Seat/rear fender/air filter case

Q’ty

Refer to “SEAT, FENDERS AND FUEL
TANK” in chapter 3.
Refer to “REAR AXLE AND REAR AXLE
HUB”.

Rear axle hub
1
2
3
4
5
6
7
8

Plate
Swingarm end cover
Rear shock absorber
Pivot shaft nut/washer
Pivot shaft
Swingarm
Drive chain guide 1
Drive sprocket cover

Remarks
Remove the parts in the order listed.

1
1
1
1/1
1
1
1
1

6-55

REAR SHOCK ABSORBER, SWINGARM AND
DRIVE CHAIN

CHAS

55 Nm (5.5 m•kg, 41 ft•lb)

23 Nm (2.3 m•kg, 17 ft•lb)

100 Nm (10.0 m•kg, 74 ft•lb)
110 Nm (11.0 m•kg, 81 ft•lb)
55 Nm (5.5 m•kg, 41 ft•lb)

Order
9

10
11

12
13
14
15
16
17

Job/Part
Drive chain guide 2
Drive chain guide 3
Nut
Lock washer
Drive sprocket
Drive chain
Dust cover/oil seal
Spacer
Bearing

Q’ty
1
1
1
1
1
1
2/2
1
2

6-56

Remarks

Refer to “INSTALLING THE DRIVE
SPROCKET”.

Refer to “INSTALLING THE
SWINGARM”.
For installation, reverse the removal
procedure.

REAR SHOCK ABSORBER, SWINGARM AND
DRIVE CHAIN

CHAS

HANDLING THE REAR SHOCK ABSORBER

WARNING
This rear shock absorber contains highly
compressed nitrogen gas. Before handling
the rear shock absorber 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.
• Do not tamper or attempt to open the rear
shock absorber.
• Do not subject the rear shock absorber 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 in any way. If the rear shock
absorber is damaged, damping performance will suffer.

DISPOSING OF A REAR SHOCK
ABSORBER
Gas pressure must be released before disposing of a rear shock absorber. To release the
gas pressure, drill a 2 ~ 3 mm (0.08 ~ 0.12 in)
hole through the rear shock absorber at point
15 ~ 20 mm (0.59 ~ 0.79 in) from its end as
shown.

WARNING
Wear eye protection to prevent eye damage
from released gas or metal chips.

6-57

REAR SHOCK ABSORBER, SWINGARM AND
DRIVE CHAIN

CHAS

EBS00487

REMOVING THE REAR SHOCK ABSORBER
1. Remove:
• rear shock absorber lower bolt
• rear shock absorber upper bolt
NOTE:
While removing the rear shock absorber lower
bolt, hold the swingarm so that it does not drop
down.
EBS00488

CHECKING THE REAR SHOCK ABSORBER
1. Check:
• shock absorber
Gas leaks/oil leaks → Replace the rear
shock absorber assembly.
• shock absorber rod
Bends/damage → Replace the rear shock
absorber assembly.
• spring
Fatigue → Replace the rear shock absorber
assembly.
Move the spring up and down.

EBS00493

NOTE:
Before removing the drive chain and the
sprockets, measure the drive chain slack and a
15-link section of the drive chain.

EBS00494

REMOVING THE SWINGARM
1. Check:
• swingarm free play
a. Check the tightening torque of the pivot
100 Nm (10.0 m•kg, 74 ft•lb)
shaft nut.

6-58

REAR SHOCK ABSORBER, SWINGARM AND
DRIVE CHAIN

CHAS

Swingarm free play limit
(at the end of the swingarm)
1.0 mm (0.04 in)
b. Check the swingarm side play
by moving it from side to side.
If side play is noticeable, check the spacer,
bearings and frame pivot.
c. Check the swingarm vertical movement
by moving it up and down.
If vertical movement is tight or rough, or if
there is binding, check the spacer, bearings
and frame pivot.
2. Remove:
• pivot shaft nut
• washer
• pivot shaft
• swingarm

EBS00495

CHECKING THE SWINGARM
1. Check:
• swingarm
Bends/cracks/damage → Replace.

2. Check:
• pivot shaft
Roll the axle on a flat surface.
Bends → Replace.

WARNING
Do not attempt to straighten a bent pivot
shaft.
3. Clean:
• pivot shaft
• spacer
• bearings
Recommended cleaning solvent
Kerosene

6-59

REAR SHOCK ABSORBER, SWINGARM AND
DRIVE CHAIN

CHAS

4. Check:
• oil seals
Damage/wear → Replace.
• bearings
Damage/pitting → Replace.

EBS00496

CHECKING THE DRIVE CHAIN
1. Measure:
• 15-link section
of the drive chain
Out of specification → Replace the drive
chain.
15-link drive chain section limit
(maximum)
239.3 mm (9.42 in)
NOTE:
• While measuring the 15-link section, push
down on the drive chain to increase its tension.
• Measure the length between drive chain roller
and
as shown.
• Perform this measurement at two or three different places.

2. Check:
• drive chain
Stiffness → Clean and lubricate or replace.

6-60

REAR SHOCK ABSORBER, SWINGARM AND
DRIVE CHAIN

CHAS

3. Clean:
• drive chain
a. Wipe the drive chain with a clean cloth.
b. Put the drive chain in kerosene and remove
any remaining dirt.
c. Remove the drive chain from the kerosene
and completely dry it.

CAUTION:
This machine has a drive chain with small
rubber O-rings
between the drive chain
side plates. Never use high-pressure water
or air, steam, gasoline, certain solvents
(e.g., benzine), or a coarse brush to clean
the drive chain. High-pressure methods
could force dirt or water into the drive
chain’s internal parts, and solvents will
deteriorate the O-rings. A coarse brush can
also damage the O-rings. Therefore, use
only kerosene to clean the drive chain.
Don’t soak the drive chain in kerosene for
more than ten minutes. Kerosene will damage the O-rings.

4. Check:
• O-rings
Damage → Replace the drive chain.
• drive chain rollers
Damage/wear → Replace the drive chain.
• drive chain side plates
Cracks/damage/wear → Replace the drive
chain.
5. Lubricate:
• drive chain
Recommended lubricant
Engine oil or chain lubricant
suitable for O-ring chains

6-61

REAR SHOCK ABSORBER, SWINGARM AND
DRIVE CHAIN

CHAS

6. Check:
• drive sprocket
• driven sprocket
More than 1/4 tooth
wear → Replace
the drive chain sprockets as a set.
Bent teeth → Replace the drive chain
sprockets as a set.
Correct
Drive chain roller
Drive chain sprocket
EBS00497

INSTALLING THE SWINGARM
1. Install:
• bearings
• spacer
NOTE:
• Inject the bearing with the character stamp
turned outward. Apply the lithium-soap-based
grease to inside.
• Apply the lithium-soap-based grease on the
spacer when installing.
Installed depth of bearing
1 ~ 2 mm (0.04 ~ 0.08 in)

EBS00498

INSTALLING THE DRIVE SPROCKET
1. Install:
• drive sprocket
• lock washer
• nut
Drive sprocket nut
110 Nm (11.0 m•kg, 81 ft•lb)
2. Bend the lock washer tab along a flat side
of the nut.

6-62

ELECTRICAL COMPONENTS
EBS00500

ELEC

ELECTRICAL

ELECTRICAL COMPONENTS
Main switch
Front brake light switch
Clutch switch
Handlebar switch
CDI unit
Starter relay
Fuse
Battery

Tail/brake light
Headlight relay
Starting circuit cut-off
relay
Thermo switch
Carburetor warmer
Starter motor

7-1

Pickup coil/stator
assembly
Neutral switch
Rear brake light switch
Ignition coil
Spark plug
Headlight

Rectifier/regulator
Neutral indicator light

CHECKING SWITCH CONTINUITY

ELEC

EBS01028

CHECKING SWITCH CONTINUITY
Check each switch for continuity with the
pocket tester. If the continuity reading is incorrect, check the wiring connections and if necessary, replace the switch.

CAUTION:
Never insert the tester probes into the coupler terminal slots
. Always insert the
probes from the opposite end of the coupler, taking care not to loosen or damage
the leads.
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
NOTE:
• Before checking for continuity, set the pocket
tester to “0” and to the “Ω × 1” range.
• When checking for continuity, switch back and
forth between the switch positions a few
times.
The terminal connections for switches (e.g.,
main switch, engine stop switch) are shown in
an illustration similar to the one on the left.
The switch positions
are shown in the far
left column and the switch lead colors
are
shown in the top row in the switch illustration.
NOTE:
“
” indicates a continuity of electricity
between switch terminals (i.e., a closed circuit
at the respective switch position).
The example illustration on the left shows
that:
There is continuity between the switch terminals for the red and brown switch leads and
between the switch terminals for the red/white
and brown/blue switch leads when the switch
is set to “ON”.

7-2

1
2
3
4
5
6
7
8

CHECKING THE SWITCHES

ELEC

EBS01029

CHECKING THE SWITCHES
Check each switch for damage or wear, proper connections, and also for continuity between the terminals. Refer to “CHECKING SWITCH CONTINUITY”.
Damage/wear → Repair or replace.
Improperly connected → Properly connect.
Incorrect continuity reading → Replace the switch.

7-3

CHECKING THE SWITCHES
Light switch
Engine stop switch
Start switch
Main switch
Front brake light switch
Clutch switch
Fuse
Neutral switch
Rear brake light switch

7-4

ELEC

CHECKING THE BULBS AND BULB SOCKETS

ELEC

EBS01030

CHECKING THE BULBS AND
BULB SOCKETS
Check each bulb and bulb socket for damage
or wear, proper connections, and also for continuity between the terminals.
Damage/wear → Repair or replace the
bulb, bulb socket or both.
Improperly connected → Properly connect.
No continuity → Repair or replace the bulb,
bulb socket or both.

TYPES OF BULBS
The bulbs used on this machine are shown in
the illustration on the left.
• Bulb
is used for the headlight and can
be pulled out by turning counterclockwise
while pushing the bulb holder and removing.
After this, you can remove the bulb.
• Bulb
is used for tail/ brake lights and can
be removed from the socket by pushing and
turning the bulb counterclockwise.
• Bulb
is used for indicator lights and can
be removed from their respective socket by
carefully pulling them out.

CHECKING THE CONDITION OF THE
BULBS
The following procedure applies to all of the
bulbs.
1. Remove:
• bulb

7-5

CHECKING THE BULBS AND BULB SOCKETS

ELEC

WARNING
Since the headlight bulb gets extremely
hot, keep flammable products and your
hands away from the bulb until it has
cooled down.

CAUTION:
• Be sure to hold the socket firmly when
removing the bulb. Never pull the lead,
otherwise it may be pulled out of the terminal in the coupler.
• Avoid touching the glass part of the headlight bulb to keep it free from oil, otherwise the transparency of the glass, the life
of the bulb, and the luminous flux will be
adversely affected. If the headlight bulb
gets soiled, thoroughly clean it with a
cloth moistened with alcohol or lacquer
thinner.
2. Check:
• bulb (for continuity)
(with the pocket tester)
No continuity → Replace.

1
1

Pocket tester
90890-03112, YU-03112-C

2
3

2
3

NOTE:
Before checking for continuity, set the pocket
tester to “0” and to the “Ω × 1” range.

a. Connect the positive tester probe to terminal
and the negative tester probe to terminal , and check the continuity.
b. Connect the positive tester probe to terminal
and the negative tester probe to terminal , and check the continuity.
c. If either of the readings indicate no continuity, replace the bulb.

7-6

CHECKING THE BULBS AND BULB SOCKETS

ELEC

CHECKING THE CONDITION OF THE BULB
SOCKETS
The following procedure applies to all of the
bulb sockets.
1. Check:
• bulb socket (for continuity)
(with the pocket tester)
No continuity → Replace
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
NOTE:
Check each bulb socket for continuity in the
same manner as described in the bulb section;
however, note the following.

a. Install a good bulb into the bulb socket.
b. Connect the pocket tester probes to the
respective leads of the bulb socket.
c. Check the bulb socket for continuity. If any
of the readings indicate no continuity,
replace the bulb socket.

7-7

7-8

B

G Y
B

G Y

Y

B

R/B L
Br R/W

L R/B
L/B Br

W

W W

W

R W

W W

W/L W/R

L

Y G
B

Y Y

G B

B

G Y

L Y

B

G Y

OFF
ON

ON
OFF

Br

Y G
B

R

R/B

W

G Y
B

OFF
PUSH

R Br

B
W

L/B

B

Br R

R
W

W
W
W

B

R

R

B

B

R

R

B

R

R

B

Y L

Y

R

Br

L/B

Y/B

R R
Y/B L/B

Y

Br

Br Y

B/Y Y/B
Sb R/B

Y Br

R/B

Sb

Y/B B/Y

R/B

W/L
W/R

Br Sb

B

W W W

Sb

Sb

Br

B/Y B

B B

O
B

A
#
B

B

B

W W B R/B
W W/R W/L O

Sb Br

B

BY

O

BY

A
#
BY

BY

BY

Br

B/Y B

WIRE HARNESS SUB-WIRE HARNESS

B B/Y

A

Pickup coil
Stator coil
Main switch
Battery positive lead
Battery
Fuse

L
Y
Y G B

OFF
LO
HI

Br

W
W
W

W/L
W/R

IGNITION SYSTEM

ELEC

EBS00503

IGNITION SYSTEM

CIRCUIT DIAGRAM

CDI unit
Ignition coil
Spark plug
Engine stop switch
Ground

IGNITION SYSTEM

ELEC

EBS01044

EBS01045

TROUBLESHOOTING

2. Battery
• Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.

The ignition system fails to operate (no
spark or intermittent spark).
Check:
1. fuse
2. battery
3. spark plug
4. ignition spark gap
5. ignition coil resistance
6. main switch
7. engine stop switch
8. pickup coil resistance
9. wiring connections (of the entire ignition
system)

Minimum open-circuit voltage
12.8 V or more at 20°C (68°F)
• Is the battery OK?
YES

• Clean the battery
terminals.
• Recharge or replace
the battery.

NOTE:
• Before troubleshooting, remove the following
part(s):
1. seat
2. front panel
3. front fender
4. rear fender
5. side cover
• Troubleshoot with the following special
tool(s).

EBS01032

3. Spark plug
• Check the condition of the spark plug.
• Check the spark plug type.
• Measure the spark plug gap.
Refer to “CHECKING THE SPARK PLUG”
in chapter 3.
Standard spark plug
DR7EA (NGK)
Spark plug gap
0.6 ~ 0.7 mm (0.024 ~ 0.028 in)

Ignition checker
90890-06754
Opama pet-4000 spark checker
YM-34487
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C

• Is the spark plug in good condition, is it of
the correct type, and is its gap within specification?
YES

NO
Re-gap or replace
the spark plug.

EBS01043

1. Fuse
• Check the fuse for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the fuse OK?
YES

NO

NO
Replace the fuse.

7-9

IGNITION SYSTEM
EBS01034

ELEC

EAS00745

4. Ignition spark gap

5. Spark plug cap resistance

The following procedure applies to all of the
spark plugs.
• Disconnect the spark plug cap from the
spark plug.
• Connect the ignition checker
and spark
plug cap
as shown.
• Set the main switch to “ON”.
• Measure the ignition spark gap .
• Crank the engine by pushing the starter
switch and gradually increase the spark gap
until a misfire occurs.

The following procedure applies to all of the
spark plug caps.
• Remove the spark plug cap from the spark
plug lead.
• Connect the pocket tester (Ω × 1k) to the
spark plug cap as shown.
• Measure the spark plug cap resistance.

1
Spark plug cap resistance
10 kΩ at 20°C (68°F)

2

a

• Is the spark plug cap OK?

Minimum ignition spark gap
6 mm (0.24 in)

YES

Replace the spark
plug cap.

• Is there a spark and is the spark gap within
specification?
NO

NO

YES
The ignition system
is OK.

7-10

ELEC

IGNITION SYSTEM
EBS01038

EBS01041

6. Ignition coil resistance

7. Main switch

• Disconnect the ignition coil coupler from the
ignition coil.
• Connect the pocket tester (Ω × 1) to the
ignition coil as shown.

• Check the main switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the main switch OK?
NO

YES

Positive tester probe →
orange lead terminal
Negative tester probe →
ignition coil base

Replace the main
switch.
EBS01042

8. Engine stop switch
• Check the engine stop switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the engine stop switch OK?
NO

YES

Replace the handlebar switch.

• Measure the primary coil resistance.
Primary coil resistance
0.18 ~ 0.28 Ω at 20°C (68°F)

EBS01040

9. Pickup coil resistance

• Connect the pocket tester (Ω × 1k) to the
ignition coil as shown.

• Disconnect the pickup coil coupler from the
wire harness.
• Connect the pocket tester (Ω × 100) to the
pickup coil terminal as shown.

Positive tester probe →
high tension code
Negative tester probe →
orange lead terminal

Positive tester probe → red terminal
Negative tester probe → white terminal

R

W

(BLACK)

• Measure the secondary coil resistance.
Secondary coil resistance
6.32 ~ 9.48 kΩ at 20°C (68°F)

• Measure the pickup coil resistance.
Pickup coil resistance
248 ~ 372 Ω at 20°C (68°F)

• Is the ignition coil OK?
YES

• Is the pickup coil OK?

NO

YES

Replace the ignition
coil.

NO
Replace the pickup
coil/stator assembly.

7-11

IGNITION SYSTEM
EBS01047

10. Wiring
• Check the entire ignition system’s wiring.
Refer to “CIRCUIT DIAGRAM”.
• Is the ignition system’s wiring properly connected and without defects?
YES
Replace
unit.

the

CDI

NO
Properly connect or
repair the ignition
system’s wiring.

7-12

ELEC

7-13

G Y
B

Y ࡯
B

G Y
B

R/B L
Br R/W

L R/B
L/B Br

W

W W

W

R W

W W

W/L W/R

L

Y G
B

Y Y

G B

B

G Y

L Y

B

G Y

OFF
ON

OFF

ON

Br

R/B

Y G
B

R

࡯
W

G Y
B

OFF
PUSH

R Br

B
W

L/B

B

Br R

R
W

W
W
W

B

R

R

B

B

R

R

B

R

R

B

Y L

Y

R

Br

L/B

Y/B

R R
Y/B L/B

Y

Br

Br Y

B/Y Y/B
Sb R/B

Y Br

R/B

Sb

Y/B B/Y

R/B

W/L
W/R

Br Sb

B

W W W

Sb

Sb

Br

B/Y B

B B

O
B

A
B

B

B

W W B R/B
W W/R W/L O

Sb Br

B

BY

O

BY

BY
A
BY

BY

Br

B/Y B

WIRE HARNESS SUB-WIRE HARNESS

B B/Y

A

Main switch
Battery positive lead
Battery
Fuse
Starter relay
Starter motor

L
Y
Y G B

OFF
LO
HI

Br

W
W

W

W/L
W/R

ELECTRIC STARTING SYSTEM

ELEC

EBS00506

ELECTRIC STARTING SYSTEM

CIRCUIT DIAGRAM

Starting circuit cut-off relay
Clutch switch
Neutral switch
Engine stop switch
Start switch
Ground

ELECTRIC STARTING SYSTEM

ELEC

EBS00508

STARTING CIRCUIT CUT-OFF SYSTEM
OPERATION
The starting circuit on this model consists of
the starter motor, starter relay, clutch switch,
and neutral switch. If the main switch is on and
the engine stop switch is in the RUN position,
the starter motor can be operated only if:

M

The transmission is in neutral (the neutral
switch is closed)
or
You pull in the clutch lever (the clutch
switch is closed).
Battery
Fuse
Main switch
Engine stop switch
Starting circuit cut-off relay
Clutch switch
Neutral switch
Start switch
Starter relay
Starter motor

7-14

ELECTRIC STARTING SYSTEM

ELEC

EBS01044

EBS01050

TROUBLESHOOTING

2. Battery
• Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.

The starter motor fails to turn.
Check:
1. fuse
2. battery
3. starter motor
4. starting circuit cut-off relay
5. starting circuit cut-off relay (diode)
6. starter relay
7. main switch
8. engine stop switch
9. neutral switch
10.clutch switch
11.start switch
12.wiring connections
(of the entire starting system)

Minimum open-circuit voltage
12.8 V or more at 20°C (68°F)
• Is the battery OK?
NO

YES

• Clean the battery
terminals.
• Recharge or replace
the battery.
EBS01051

3. Starter motor

NOTE:
• Before troubleshooting, remove the following
part(s):
1. seat
2. front panel
3. front fender
4. rear fender
5. side cover
• Troubleshoot with the following special
tool(s).

• Connect the positive battery terminal
and starter motor lead
with a jumper
lead .

Pocket tester
90890-03112, YU-03112-C
EBS01043

WARNING

1. Fuse

• A wire that is used as a jumper lead
must have at least the same capacity or
more as that of the battery lead, otherwise the jumper lead may burn.
• This check is likely to produce sparks,
therefore make sure nothing flammable
is in the vicinity.

• Check the fuse for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the fuse OK?
YES

NO
Replace the fuse.

• Does the starter motor turn?
YES

NO
Repair or replace
the starter motor.

7-15

ELECTRIC STARTING SYSTEM
EBS01052

ELEC

EBS01053

4. Starting circuit cut-off relay

5. Starting circuit cut-off relay (diode)

• Remove the starting circuit cut-off relay
from the wire harness.
• Connect the pocket tester (Ω × 1) and battery (12 V) to the starting circuit cut-off relay
as shown.

• Remove the starting circuit cut-off relay
from the wire harness.
• Connect the pocket tester (Ω × 1) to the
starting circuit cut-off relay as shown.
• Measure the starting circuit cut-off relay for
continuity as follows.

Positive battery terminal → red/black
Negative battery terminal →
sky blue
or black/yellow
Positive tester probe → red/black
Negative tester probe → yellow/black

Positive tester probe →
sky blue
Negative tester probe →
red/black

Continuity

Positive tester probe →
red/black
Negative tester probe →
sky blue

No
continuity

• Does the starting circuit cut-off relay have
continuity between red/black and yellow/
black?
YES

NO

NOTE:
When you switch the tester’s positive and
negative probes, the readings in the above
chart will be reversed.

Replace the starting
circuit cut-off relay.

• Are the testing readings correct?
YES

NO
Replace the starting
circuit cut-off relay.

7-16

ELECTRIC STARTING SYSTEM
EBS01054

ELEC

EBS01042

6. Starter relay

8. Engine stop switch

• Disconnect the starter relay coupler from
the wire harness.
• Connect the pocket tester (Ω × 1) and battery (12 V) to the starter relay as shown.

• Check the engine stop switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the engine stop switch OK?
YES

Positive battery terminal → blue/black
Negative battery terminal →
yellow/black

NO
Replace the handlebar switch.

Positive tester probe → red
Negative tester probe → black
EBS01046

9. Neutral switch
• Check the neutral switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the neutral switch OK?

R
R

R

Y/B L/B

YES

B

NO
Replace the neutral
switch.

• Does the starter relay have continuity
between red and black?
YES

EBS01056

10. Clutch switch

NO

• Check the clutch switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the clutch switch OK?

Replace the starter
relay.

YES

NO

EBS01041

7. Main switch

Replace the clutch
switch.

• Check the main switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the main switch OK?
YES

EBS01057

11. Start switch

NO

• Check the start switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the start switch OK?

Replace the main
switch.

YES

NO
Replace the handlebar switch.

7-17

ELECTRIC STARTING SYSTEM
EBS01059

12. Wiring
• Check the entire starting system’s wiring.
Refer to “CIRCUIT DIAGRAM”.
• Is the starting system’s wiring properly connected and without defects?
YES
The starting system
circuit is OK.

NO
Properly connect or
repair the starting
system’s wiring.

7-18

ELEC

STARTER MOTOR

ELEC

EBS01061

STARTER MOTOR

10 Nm (1.0 m•kg, 7.4 ft•lb)

7 Nm (0.7 m•kg, 5.2 ft•lb)

10 Nm (1.0 m•kg, 7.4 ft•lb)

Order

1
2
3

Job/Part
Removing the starter motor
Exhaust pipe
Idle gear cover and idle gear
Clutch cable holder
Starter motor lead
Starter motor

Q’ty

1
1
1

Remarks
Remove the parts in the order listed.
Refer to “ENGINE REMOVAL” in chapter
4.
Disconnect.
For installation, reverse the removal
procedure.

7-19

STARTER MOTOR

ELEC

EBS01062

Order

Job/Part
Disassembling the starter motor
Front bracket
Tang washer
Plate washer
Circlip
Rear bracket/Brush
Armature assembly
Starter motor yoke
Brush/spring

Q’ty
1
1
1
1
1/1
1
1
2/2

Remarks
Remove the parts in the order listed.

Refer to “ASSEMBLING THE STARTER
MOTOR”.

For assembly, reverse the disassembly
procedure.

7-20

STARTER MOTOR

ELEC

EBS01064

CHECKING THE STARTER MOTOR
1. Check:
• commutator
Dirt → Clean with 600-grit sandpaper.
2. Measure:
• commutator diameter
Out of specification → Replace the starter
motor.
Commutator wear limit
21 mm (0.83 in)
3. Measure:
• mica undercut
Out of specification → Scrape the mica to
the proper measurement with a hacksaw
blade that has been grounded to fit the
commutator.
Mica undercut
1.5 mm (0.06 in)
NOTE:
The mica of the commutator must be undercut
to ensure proper operation of the commutator.

4. Measure:
• armature assembly resistances
(commutator and insulation)
Out of specification → Replace the starter
motor.
a. Measure the armature assembly resistances with the pocket tester.
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
Armature coil
Commutator resistance
0.013 ~ 0.015 Ω at 20°C (68°F)
Insulation resistance
Above 1 MΩ at 20°C (68°F)

7-21

STARTER MOTOR

ELEC

b. If any resistance is out of specification,
replace the starter motor.

5. Measure:
• brush length
Out of specification → Replace the brushes
as a set.
Brush length wear limit
3.5 mm (0.14 in)
6. Measure:
• brush spring force
Out of specification → Replace the brush
springs as a set.
Brush spring force
5.52 ~ 8.28 N
(563 ~ 844 gf, 19.85 ~ 29.78 oz)
7. Check:
• gear teeth
Damage/wear → Replace the gear.
8. Check:
• bushing
• bearing
• oil seal
Damage/wear → Replace the defective
part(s).

7-22

STARTER MOTOR

ELEC

EBS00515

ASSEMBLING THE STARTER MOTOR
1. Install:
• brush spring
• brush

2

2
1
2. Install:
• armature coil

1

3. Install
• O-rings

1

to starter motor yoke

.

2

b

4. Install
• Starter motor yoke
NOTE:
Align the match marks

a

on the starter motor
york
with the match marks
on the rear
bracket.

1
b

5. Install
• Tang washer
• Plate washer
• Front bracket
NOTE:
Align the match marks

a

1

york with the match marks

3

2

7-23

on the starter motor
on the front bracket.

ELEC

CHARGING SYSTEM
EBS00516

CHARGING SYSTEM

L/B

B

B

R
R
Br R

R
W

W W

W
W
W

Stator coil
Rectifier/regulator
Battery positive lead
Battery
Fuse
Ground

W W

W
W

W/L W/R

R W

W/L
W/R

ON
OFF

R

Br

B
W

R Br

W

W
W
W

B

R
R

B

R

R

R

Y/B

R R
Y/B L/B

CIRCUIT DIAGRAM

7-24

CHARGING SYSTEM

ELEC

EBS01044

EBS01065

TROUBLESHOOTING

2. Battery
• Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.

The battery is not being charged.
Check:
1. fuse
2. battery
3. charging voltage
4. stator coil resistance
5. wiring connections
(of the entire charging system)

Minimum open-circuit voltage
12.8 V or more at 20°C (68°F)
• Is the battery OK?
YES

NOTE:
• Before troubleshooting, remove the following
part(s):
1. seat
2. front panel
3. front fender
4. rear fender
5. side cover
• Troubleshoot with the following special
tool(s).

• Clean the battery
terminals.
• Recharge or replace
the battery.

Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
EBS01043

1. Fuse
• Check the fuse for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the fuse OK?
YES

NO

NO
Replace the fuse.

7-25

ELEC

CHARGING SYSTEM
EBS01066

EBS01100

3. Charging voltage

4. Stator coil resistance

• Connect the engine tachometer to on to the
ignition coil.
• Connect the pocket tester (DC 20 V) to the
battery as shown.

• Disconnect the AC magneto coupler from
the wire harness.
• Connect the pocket tester (Ω × 1) to the
charging coils.

Positive tester probe →

Tester (+) lead → White terminal
Tester (–) lead → White terminal

positive battery terminal

Negative tester probe →
negative battery terminal

Tester (+) lead → White terminal
Tester (–) lead → White terminal
Tester (+) lead → White terminal
Tester (–) lead → White terminal

• Start the engine and let it run at approximately 5,000 r/min.
• Measure the charging voltage.

• Measure the stator coil resistance.

Charging voltage
14 V at 5,000 r/min

Charging coil resistance:
0.688 ~ 1.032 Ω at 20°C (68°F)

NOTE:
Make sure the battery is fully charged.

YES

Replace the pickup
coil/stator assembly.

• Is the charging voltage within specification?
NO

NO

YES
5. Wiring

The charging circuit
is OK.

• Check the entire charging system’s wiring.
Refer to “CIRCUIT DIAGRAM”.
• Is the charging system’s wiring properly
connected and without defects?
YES
Replace the rectifier/
regulator.

7-26

NO
Replace the diode
and properly connect or repair the
charging
system’s
wiring.

7-27

G Y
B

Y ࡯
B

G Y
B

R/B L
Br R/W

L R/B
L/B Br

W

W W

W

R W

W W

W/L W/R

L

Y G
B

Y Y

G B

B

G Y

L Y

B

G Y

OFF
ON

OFF

ON

Br

R/B

Y G
B

R

࡯
W

G Y
B

OFF
PUSH

R Br

B
W

L/B

B

Br R

R
W

W
W
W

B

R

R

B

B

R

R

B

R

R

B

Y L

Y

R

Br

L/B

Y/B

R R
Y/B L/B

Y

Br

Br Y

B/Y Y/B
Sb R/B

Y Br

R/B

Sb

Y/B B/Y

R/B

W/L
W/R

Br Sb

B

W W W

Sb

Sb

Br

B/Y B

B B

O
B

A
B

B

B

W W B R/B
W W/R W/L O

Sb Br

B

BY

O

BY

BY
A
BY

BY

Br

B/Y B

WIRE HARNESS SUB-WIRE HARNESS

B B/Y

A

Stator coil
Rectifier/regulator
Main switch
Battery positive lead
Battery
Fuse

L
Y
Y G B

OFF
LO
HI

Br

W
W
W

W/L
W/R

LIGHTING SYSTEM

ELEC

EBS00518

LIGHTING SYSTEM

CIRCUIT DIAGRAM

Tail/brake light
Light switch
Headlight relay
Headlight
Ground

ELEC

LIGHTING SYSTEM
EBS01067

EAS00776

TROUBLESHOOTING

2. Stator coil resistance
• Disconnect the AC magneto coupler from
the wire harness.
• Connect the pocket tester (Ω × 1) to the
charging coils.

Any of the following fail to light: headlight, tail/brake light.
Check:
1. light switch
2. Stator coil resistance
3. wiring connections
(of the entire lighting system)
NOTE:
• Before troubleshooting, remove the following
part(s):
1. seat
2. front panel
3. front fender
4. rear fender
5. side cover
• Troubleshoot with the following special
tool(s).

Tester (+) lead → White terminal
Tester (–) lead → White terminal
Tester (+) lead → White terminal
Tester (–) lead → White terminal
Tester (+) lead → White terminal
Tester (–) lead → White terminal

Pocket tester
90890-03112
Analog pocket tester
YU-03112-C

• Measure the stator coil resistance.
Charging coil resistance:
0.688 ~ 1.032 Ω at 20°C (68°F)

EAS00783

YES

1. Light switch
• Check the light switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the light switch OK?
YES

NO
Replace the pickup
coil/stator assembly.

NO
Replace the handlebar switch.

7-28

LIGHTING SYSTEM

ELEC

EBS01069

3. Wiring

2. Voltage

• Check the entire lighting system’s wiring.
Refer to “CIRCUIT DIAGRAM”.
• Is the lighting system’s wiring properly connected and without defects?

• Connect the pocket tester (AC 20 V) to the
headlight couplers as shown.

Headlight coupler (wire harness side)

NO

YES
Check the condition
of each of the lighting system’s circuits.
Refer to “CHECKING THE LIGHTING SYSTEM”.

When the light switch is set to “LO”
When the light switch is set to “HI”

Headlight
Positive tester probe →
yellow
or green
Negative tester probe → black

Properly connect or
repair the lighting
system’s wiring.

EBS01070

CHECKING THE LIGHTING SYSTEM
1. The headlights fail to come on.
1. Headlight bulb and socket
• Check the headlight bulb and socket for
continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.
• Are the headlight bulb and socket OK?
YES

• Set the main switch to “ON”.
• Start the engine.
• Set the light switch to “LO” or “HI”.
• Measure the voltage (AC 12 V) of yellow
or green
on the headlight coupler (wire
harness side).
• Is the voltage within specification?

NO
Replace the headlight bulb, socket or
both.

YES
This circuit is OK.

7-29

NO
Replace the rectifier/
regulator.

LIGHTING SYSTEM
2. The tail/brake light fails to come on.

ELEC

3. Voltage

1. Tail/brake light bulb and bulb socket
(4D31)

• Connect the pocket tester (AC 20 V) to the
tail/brake light coupler as shown.

• Check the tail/brake light bulb and socket
for continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.
• Are the tail/brake light bulb and socket OK?

Tail/brake light coupler (wire harness side)
Tail/brake light
Positive tester probe → blue
Negative tester probe → black

NO

YES

Replace the tail/brake
light bulb, socket or
both.
2. Tail/brake light (4D35, 4D39)
• Disconnect the tail/brake light coupler.
• Connect the battery (12 V) to the tail/brake
light coupler terminals as shown.
• When the jumper leads are connected to
the terminals, the tail/brake light should illuminate.

• Set the main switch to “ON”.
• Start the engine.
• Measure the voltage (AC 12 V) of blue
on the tail/brake light coupler (wire harness
side).
• Is the voltage within specification?

Positive battery terminal → blue
Negative battery terminal → black

YES
This circuit is OK.

• Is the tail/brake light OK?
YES

NO
Replace the
brake light.

tail/

7-30

NO
Replace the rectifier/
regulator.

7-31

G Y
B

Y ࡯
B

G Y
B

R/B L
Br R/W

L R/B
L/B Br

W

W W

W

R W

W W

W/L W/R

L

Y G
B

Y Y

G B

B

G Y

L Y

B

G Y

OFF
ON

OFF

ON

Br

R/B

Y G
B

R

࡯
W

G Y
B

OFF
PUSH

R Br

B
W

L/B

B

Br R

R
W

W
W
W

B

R

R

B

B

R

R

B

R

R

B

Y L

Y

R

Br

L/B

Y/B

R R
Y/B L/B

Y

Br

Br Y

B/Y Y/B
Sb R/B

Y Br

R/B

Sb

Y/B B/Y

R/B

W/L
W/R

Br Sb

B

W W W

Sb

Sb

Br

B/Y B

B B

O
B

A
B

B

B

W W B R/B
W W/R W/L O

Sb Br

B

BY

O

BY

BY
A
BY

BY

Br

B/Y B

WIRE HARNESS SUB-WIRE HARNESS

B B/Y

A

Main switch
Battery positive lead
Battery
Fuse
Neutral indicator light
Neutral switch

L
Y
Y G B

OFF
LO
HI

Br

W
W

W

W/L
W/R

SIGNAL SYSTEM

ELEC

EBS00521

SIGNAL SYSTEM

CIRCUIT DIAGRAM
Rear brake light switch
Front brake light switch
Tail/brake light
Ground

SIGNAL SYSTEM
EBS01073

ELEC

EBS01044

TROUBLESHOOTING

2. Battery
• Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.

Any of the following fail to light: brake
light or an indicator light.
Check:
1. fuse
2. battery
3. main switch
4. wiring connections
(of the entire signaling system)
NOTE:
• Before troubleshooting, remove the following
part(s):
1. seat
2. front fender
• Troubleshoot with the following special
tool(s).

Minimum open-circuit voltage
12.8 V or more at 20°C (68°F)
• Is the battery OK?
YES

NO
• Clean the battery
terminals.
• Recharge or replace
the battery.

EBS01041

3. Main switch
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C

• Check the main switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the main switch OK?
YES

NO

EBS01043

Replace the main
switch.

1. Fuse
• Check the fuse for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the fuse OK?
YES

EBS01074

4. Wiring

NO

• Check the entire signal system’s wiring.
Refer to “CIRCUIT DIAGRAM”.
• Is the signaling system’s wiring properly
connected and without defects?

Replace the fuse.

YES
Check the condition
of each of the signaling system’s circuits.
Refer to “CHECKING THE SIGNALING SYSTEM”.

7-32

NO
Properly connect or
repair the signaling
system’s wiring.

SIGNAL SYSTEM
EBS01075

3. Brake light switches

CHECKING THE SIGNALING SYSTEM

• Check the brake light switches for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the brake light switch OK?

EBS01076

1. The tail/brake light fails to come on.
1. Tail/brake light bulb and bulb socket
(4D31)

NO

YES

• Check the tail/brake light bulb and bulb
socket for continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.
• Are the tail/brake light bulb and bulb socket
OK?

Replace the brake
light switch.
4. Voltage

NO

YES

ELEC

• Connect the pocket tester (DC 20 V) to the
tail/brake light coupler (wire harness side)
as shown.

Replace the tail/
brake light bulb, bulb
socket or both.

Positive tester probe → yellow
Negative tester probe → black

2. Tail/brake light (4D35, 4D39)
• Disconnect the tail/brake light coupler.
• Connect the battery (12 V) to the tail/brake
light coupler terminals as shown.
• When the jumper leads are connected to
the terminals, the tail/brake light should illuminate.
Positive battery terminal → yellow
Negative battery terminal → black

• Set the main switch to “ON”.
• Pull in the brake lever or push down on the
brake pedal.
• Measure the voltage (DC 12 V) of yellow
on the tail/brake light coupler (wire harness
side).
• Is the voltage within specification?
YES
This circuit is OK.

• Is the tail/brake light OK?
YES

NO
Replace the
brake light.

tail/

7-33

NO
The wiring circuit
from the main switch
to the tail/brake light
coupler is faulty and
must be repaired.

SIGNAL SYSTEM
EBS01077

3. Voltage

2. The neutral indicator light fails to come on.

• Connect the pocket tester (DC 20 V) to the
indicator light coupler (wire harness side)
as shown.

1. Neutral indicator light bulb and socket
• Check the neutral indicator light bulb and
socket for continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.
• Are the neutral indicator light bulb and
socket OK?
YES

ELEC

Positive tester probe → brown
Negative tester probe → sky blue

NO
Br Sb

Sb Br

Replace the neutral
indicator light bulb,
socket or both.
• Set the main switch to “ON”.
• Measure the voltage (DC 12 V).
• Is the voltage within specification?

2. Neutral switch
• Check the neutral switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the neutral switch OK?
YES

YES

NO

This circuit is OK.

Replace the neutral
switch.

7-34

NO
The wiring circuit
from the main switch
to the indicator light
coupler is faulty and
must be repaired.

SIGNAL SYSTEM
EBS01083

ELEC

2. Carburetor warmer

3. The carburetor heater fails to come on.

• Remove the carburetor heating element
from the carburetor.
• Connect the pocket tester (Ω × 1) to the carburetor heating element.

1. Thermo switch
• Disconnect the thermo switch from the wireharness.
• Connect the pocket tester (Ω × 1) to the
thermo switch lead.

Tester positive probe →
heating element
Tester negative probe →
heating element body

Tester positive probe → black
Tester negative probe → black

1

2

• Measure the carburetor heating element
resistance.

• Check the thermo switch for continuity at
the temperatures indicated below.

Carburetor heating element resistance:
6 ~ 12 Ω (20°C)

OFF

• Is the carburetor heating element OK?
ON

YES
16°C±3°C
(60.8°F±5.4°F)

11°C±3°C
(51.8°F±5.4°F)

This circuit is OK.

COOL DOWN
HEAT UP
• Does the thermo switch operated properly?
YES

NO
Replace the thermo
switch.

7-35

NO
Replace the carburetor warmer element.

STARTING FAILURE/HARD STARTING

TRBL
SHTG

EBS00537

TROUBLESHOOTING
NOTE:
The following troubleshooting does not cover all the possible causes of trouble. It should be helpful,
however, as a guide to troubleshooting. Refer to the relative procedure in this manual for check,
adjustment and replacement of parts.

STARTING FAILURE/HARD STARTING
FUEL SYSTEM
Fuel tank
• Empty
• Clogged fuel strainer
• Clogged fuel tank breather hose
• Deteriorated or contaminated fuel
Fuel cock
• Clogged fuel hose
Carburetor
• Deteriorated or contaminated fuel
• Clogged pilot jet
• Clogged pilot air passage
• Sucked-in air
• Deformed float
• Worn needle valve
• Improperly sealed valve seat
• Improperly adjusted fuel level
• Improperly set pilot jet
• Clogged starter jet
• Choke valve malfunction
Air filter
• Clogged air filter element

ELECTRICAL SYSTEM
Spark plug
• Improper plug gap
• Worn electrodes
• Wire between terminals broken
• Improper heat range
Ignition coil
• Broken or shorted primary/secondary
• Faulty ignition coil lead
• Broken body
CDI system
• Faulty CDI unit
• Faulty pickup coil
• Faulty lighting coil
• Faulty charging coil
• Broken woodruff key
Switches and wiring
• Faulty main switch
• Faulty engine stop switch
• Broken or shorted wiring
• Faulty neutral switch
• Faulty start switch
• Faulty clutch switch
• Faulty throttle switch
• Faulty carburetor switch
• Loose connections
Starter motor
• Faulty starter motor
• Faulty starter relay
• Faulty starting circuit cut-off relay
• Faulty starter clutch
• Faulty torque limiter
Battery
• Faulty battery
• Discharged battery

8-1

1
2
3
4
5
6
7
8

STARTING FAILURE/HARD STARTING/POOR IDLE SPEED
PERFORMANCE/POOR MEDIUM AND HIGH-SPEED PERFORMANCE
COMPRESSION SYSTEM
Cylinder and cylinder head
• Loose spark plug
• Loose cylinder head or cylinder
• Broken cylinder head gasket
• Broken cylinder gasket
• Worn, damaged or seized cylinder
Valve and camshaft
• Improperly sealed valve
• Improperly contacted valve and valve seat
• Improper valve timing
• Broken valve spring
• Seized camshaft

TRBL
SHTG

Piston and piston rings
• Improperly installed piston ring
• Worn, fatigued or broken piston ring
• Seized piston ring
• Seized or damaged piston
Crankcase and crankshaft
• Improperly seated crankcase
• Seized crankshaft
Valve train
• Improperly adjusted valve clearance
• Improperly adjusted valve timing

EBS00538

POOR IDLE SPEED PERFORMANCE
POOR IDLE SPEED PERFORMANCE
Carburetor
• Improperly returned choke
• Loose or clogged pilot jet
• Loose or clogged pilot air jet
• Improperly adjusted idle speed
(throttle stop screw)
• Improper throttle cable play
• Flooded carburetor
Intake manifold
• Loosen carburetor joint

Electrical system
• Faulty battery
• Faulty CDI unit
• Faulty pickup coil
• Faulty ignition coil
Valve train
• Improperly adjusted valve clearance
Air filter
• Clogged air filter element
• Loosen air filter joint

EBS00539

POOR MEDIUM AND HIGH-SPEED PERFORMANCE
POOR MEDIUM AND HIGH-SPEED PERFORMANCE
Refer to “STARTING FAILURE/HARD STARTING” and “POOR IDLE SPEED PERFORMANCE—
Valve train”.
Carburetor
Air filter
• Improper jet needle clip position
• Clogged air filter element
• Improperly adjusted fuel level
• Clogged or loose main jet
• Deteriorated or contaminated fuel

8-2

FAULTY GEAR SHIFTING/
CLUTCH SLIPPING/DRAGGING

TRBL
SHTG

EBS00541

FAULTY GEAR SHIFTING
HARD SHIFTING
Refer to “CLUTCH DRAGGING”.

SHIFT PEDAL DOES NOT MOVE
Shift shaft
• Bent shift shaft
Shift drum and shift forks
• Groove jammed with impurities
• Seized shift fork
• Bent shift fork guide bar

Transmission
• Seized transmission gear
• Jammed impurities
• Incorrectly assembled transmission
Shift guide
• Broken shift guide

JUMPS OUT GEAR
Shift shaft
• Improperly adjusted shift lever position
• Improperly returned stopper lever
Shift forks
• Worn shift fork

Shift drum
• Improper thrust play
• Worn shift drum groove
Transmission
• Worn gear dog

EBS00545

CLUTCH SLIPPING/DRAGGING
CLUTCH SLIPPING
Clutch
• Loose clutch spring
• Fatigued clutch spring
• Worn friction plate
• Worn clutch plate
• Incorrectly assembled clutch

Engine oil
• Low oil level
• Improper quality (low viscosity)
• Deterioration

CLUTCH DRAGGING
Clutch
• Warped pressure plate
• Unevenly tensioned clutch springs
• Loose clutch boss nut
• Burnt primary driven gear bushing
• Bent clutch plate
• Swollen friction plate
• Broken clutch boss

Engine oil
• High oil level
• Improper quality (high viscosity)
• Deterioration

8-3

OVERHEATING/ FAULTY BRAKE /
SHOCK ABSORBER MALFUNCTION
EBS00547

OVERHEATING
OVERHEATING
Ignition system
• Improper spark plug gap
• Improper spark plug heat range
• Faulty CDI unit
Fuel system
• Improper carburetor main jet
(improper setting)
• Improper fuel level
• Clogged air filter element
Compression system
• Heavy carbon deposit

Engine oil
• Improper oil level
• Improper oil viscosity
• Inferior oil quality
Brake
• Brake drag

EBS00550

FAULTY BRAKE
POOR BRAKING EFFECT
Disc brake
• Worn brake pads
• Worn disc
• Air in brake fluid
• Leaking brake fluid
• Faulty master cylinder kit cup
• Faulty caliper kit seal
• Loose union bolt
• Broken brake hose and pipe
• Oily or greasy disc/brake pads
• Improper brake fluid level

EBS00551

SHOCK ABSORBER MALFUNCTION
MALFUNCTION
• Bent or damaged damper rod
• Damaged oil seal lip
• Fatigued shock absorber spring
• Leaking oil or gas

8-4

TRBL
SHTG

UNSTABLE HANDLING/
LIGHTING SYSTEM

TRBL
SHTG

EBS00552

UNSTABLE HANDLING
UNSTABLE HANDLING
Handlebar
• Improperly installed or bent
Steering
• Incorrect toe-in
• Bent steering stem
• Improperly installed steering stem
• Damaged bearing or bearing race
• Bent tie-rods
• Deformed steering knuckles
Tires
• Uneven tire pressures on both sides
• Incorrect tire pressure
• Uneven tire wear

Wheels
• Deformed wheel
• Loose bearing
• Bent or loose wheel axle
• Excessive wheel runout
Frame
• Bent
• Damaged frame
Swingarm
• Worn bearing or bushing
• Bent or damaged

EBS00553

LIGHTING SYSTEM
HEADLIGHT DOES NOT COME ON
• Improper bulb
• Too many electric accessories
• Hard charging (broken stator coil and/or
faulty rectifier/regulator)
• Incorrect connection
• Improperly grounded
• Poor contacts (main or light switch)
• Bulb life expired

BULB BURNT OUT
• Improper bulb
• Faulty battery
• Faulty rectifier/regulator
• Improperly grounded
• Faulty main and/or light switch
• Bulb life expired
TAIL/BRAKE LIGHT BULB BURNT OUT
• Wrong tail/brake light bulb
• Faulty battery
• Faulty rectifier/regulator
• Improperly grounded
• Faulty main and/or light switch
• Incorrectly adjusted rear brake light switch
• Tail/brake light bulb life expired

TAIL/BRAKE LIGHT DOES NOT LIGHT
• Wrong tail/brake light bulb
• Too many electrical accessories
• Hard charging (broken stator coil and/or
faulty rectifier/regulator)
• Incorrect connection
• Improperly grounded
• Poor contacts (main or light switch)
• Burnt-out tail/brake light bulb

8-5

YAMAHA MOTOR CO., LTD.
2500 SHINGAI IWATA SHIZUOKA JAPAN

PRINTED IN U.S.A.

YFM250RX WIRING DIAGRAM

Pickup coil
Stator coil
Rectifier/regulator
Main switch
Battery positive lead
Battery
Fuse
Starter relay
Starter motor
CDI unit
Ignition coil
Spark plug
Starting circuit cut-off relay
Clutch switch
Thermo switch
Carburetor warmer
Neutral indicator light
Neutral switch
Rear brake light switch
Front brake light switch
Tail/brake light
Handlebar switch
Light switch
Engine stop switch
Start switch
Headlight relay
Headlight
Ground

COLOR CODE
B . . . . . . . Black
Br . . . . . . Brown
G . . . . . . Green
L . . . . . . . Blue
O . . . . . . Orange
R. . . . . . . Red

Sb . . . . .
W .....
Y......
B/Y . . . .
L/B . . . .
R/B . . . .

Sky blue
White
Yellow
Black/Yellow
Blue/Black
Red/Black

R/W . . . .
W/L . . . .
W/R . . . .
Y/B. . . . .

Red/White
White/Blue
White/Red
Yellow/Black

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4D3 28197 10 2008 Yamaha Raptor 250 Sevice Manual

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