2008
SERVICE MANUAL
YXR70FX
LIT-11616-21-58 5B4-F8197-10
EBS00001
©2007 by Yamaha Motor Corporation, U.S.A.
YXR70FX
SERVICE MANUAL
First edition, September 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-11616-21-58
EBS00002
IMPORTANT
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 vehicle has a basic understanding of the mechanical ideas and the procedures of vehicle
repair. Repairs attempted by anyone without this knowledge are likely to render the vehicle unsafe
and unfit for use.
This model has been designed and manufactured to perform within certain specifications in regard
to performance and emissions. Proper service with the correct tools is necessary to ensure that the
vehicle will operate as designed. If there is any question about a service procedure, it is imperative
that you contact a Yamaha dealer for any service information changes that apply to this model. This
policy is intended to provide the customer with the most satisfaction from his vehicle and to conform
to federal environmental quality objectives.
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.
TIP:
_
• This Service Manual contains information regarding periodic maintenance to the emission control
system. Please read this material carefully.
• Designs and specifications are subject to change without notice.
EBS00003
IMPORTANT INFORMATION
Particularly important information is distinguished in this manual by the following notations.
This is the safety alert symbol. It is used to alert you to potential personal injury
hazards. Obey all safety messages that follow this symbol to avoid possible
injury or death.
WARNING
NOTICE
TIP:
A WARNING indicates a hazardous situation which, if not avoided, could result
in death or serious injury.
A NOTICE indicates special precautions that must be taken to avoid damage to
the vehicle or other property.
A TIP provides key information to make procedures easier or clearer.
EBS00004
HOW TO USE THIS MANUAL
MANUAL ORGANIZATION
This manual consists of chapters for the main categories of subjects. (See “symbols”)
1st title 1: This is the title of the chapter with its symbol in the upper right corner of each page.
2nd title 2: This title indicates the section of the chapter and only appears on the first page of each
section. It is located in the upper left corner of the page.
3rd title 3: This title indicates a sub-section that is followed by step-by-step procedures 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 4 is provided for removal and disassembly jobs.
2. Numbers 5 are given in the order of the jobs in the exploded diagram. A number that is enclosed
by a circle indicates a disassembly step.
3. An explanation of jobs and notes is presented in an easy-to-read way by the use of symbol marks
6
. The meanings of the symbol marks are given on the next page.
4. A job instruction chart 7 accompanies the exploded diagram, providing the order of jobs, names
of parts, notes in jobs, etc.
5. For jobs requiring more information, the step-by-step format supplements 8 are given in addition
to the exploded diagram and the job instruction chart.
4
5
6
7
2 3
1
8
12
GEN
INFO
34
SPEC
CHK
ENG
ADJ
56
COOL
78
FI
EBS00006
SYMBOLS
The following symbols are not relevant to
every vehicle.
Symbols 1 to 0 indicate the subject of each
chapter.
General information
1
Specifications
2
Periodic checks and adjustments
3
Engine
4
Cooling system
5
Fuel injection system
6
Drive train
7
Chassis
8
Electrical
9
Troubleshooting
0
DRIV
90
–+
ELEC
ABC
DEF
GH
IJKL
E
MNOP
B
QR
LT
G
LS
CHAS
TRBL
SHTG
T
.
R
.
M
M
New
BF
S
Symbols A to H indicate the following
Can be serviced with engine mounted
A
Filling fluid
B
Lubricant
C
Special tool
D
Torque
E
Wear limit, clearance
F
Engine speed
G
Electrical data (Ω, V, A)
H
Symbols I to P in the exploded diagrams
indicate the types of lubricants and lubrication
points.
Apply engine oil
I
Apply gear oil
J
Apply molybdenum disulfide oil
K
Apply brake fluid
L
Apply wheel bearing grease
M
Apply lithium-soap-based grease
N
Apply molybdenum disulfide grease
O
Apply silicone grease
P
Symbols Q to R in the exploded diagrams
indicate where to apply a locking agent Q and
when to install a new part R.
®
Apply the locking agent (LOCTITE
Q
Replace
R
)
EBS00008
TABLE OF CONTENTS
GENERAL INFORMATION
SPECIFICATIONS
PERIODIC CHECKS AND
ADJUSTMENTS
ENGINE
COOLING SYSTEM
GEN
INFO
SPEC
CHK
ADJ
ENG
COOL
1
2
3
4
5
FUEL INJECTION SYSTEM
DRIVE TRAIN
CHASSIS
ELECTRICAL
TROUBLESHOOTING
FI
DRIV
CHAS
– +
ELEC
TRBL
SHTG
6
7
8
9
10
CONTENTS
CHAPTER 1
GENERAL INFORMATION
VEHICLE IDENTIFICATION
VEHICLE IDENTIFICATION NUMBER .....................................................1-1
MODEL LABEL..........................................................................................1-1
FEATURES
OUTLINE OF THE FI SYSTEM.................................................................1-2
FI SYSTEM................................................................................................ 1-3
INSTRUMENT FUNCTIONS .....................................................................1-4
IMPORTANT INFORMATION
PREPARATION FOR REMOVAL AND DISASSEMBLY........................... 1-7
REPLACEMENT PARTS...........................................................................1-7
GASKETS, OIL SEALS AND O-RINGS .................................................... 1-7
LOCK WASHERS/PLATES AND COTTER PINS .....................................1-8
BEARINGS AND OIL SEALS .................................................................... 1-8
CIRCLIPS ..................................................................................................1-8
CHECKING THE CONNECTIONS............................................................1-9
SPECIAL TOOLS
......................................................................................................1-2
..........................................................................................1-10
............................................................................1-1
.........................................................................1-7
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS
ENGINE SPECIFICATIONS
CHASSIS SPECIFICATIONS
ELECTRICAL SPECIFICATIONS
TIGHTENING TORQUES
ENGINE TIGHTENING TORQUES.........................................................2-17
CHASSIS TIGHTENING TORQUES.......................................................2-20
HOW TO USE THE CONVERSION TABLE
........................................................................2-1
............................................................................2-5
........................................................................2-12
.................................................................2-15
..............................................................................2-17
..................................................2-24
GENERAL TIGHTENING TORQUE SPECIFICATIONS...............................2-24
LUBRICATION POINTS AND LUBRICANT TYPES ....................................2-25
ENGINE...................................................................................................2-25
COOLANT FLOW DIAGRAMS .....................................................................2-27
OIL FLOW DIAGRAMS.................................................................................2-29
CABLE ROUTING .........................................................................................2-32
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
ENGINE ...........................................................................................................3-3
ADJUSTING THE VALVE CLEARANCE ..................................................3-3
ADJUSTING THE THROTTLE CABLE .....................................................3-6
CHECKING THE SPARK PLUG ...............................................................3-7
CHECKING THE IGNITION TIMING.........................................................3-9
MEASURING THE COMPRESSION PRESSURE..................................3-10
CHECKING THE ENGINE OIL LEVEL.................................................... 3-13
CHANGING THE ENGINE OIL ...............................................................3-14
CLEANING THE AIR FILTER ELEMENT................................................3-16
CHECKING THE THROTTLE BODY JOINT...........................................3-19
CHECKING THE FUEL HOSE ................................................................ 3-19
CHECKING THE BREATHER HOSES ................................................... 3-19
CHECKING THE COOLANT LEVEL.......................................................3-20
CHANGING THE COOLANT...................................................................3-21
CHECKING THE COOLING SYSTEM .................................................... 3-25
CHECKING THE COOLANT TEMPERATURE WARNING LIGHT.........3-26
CHECKING AND REPLACING THE V-BELT .........................................3-27
CHECKING THE EXHAUST SYSTEM.................................................... 3-28
CLEANING THE SPARK ARRESTER ....................................................3-29
CHASSIS .......................................................................................................3-30
ADJUSTING THE BRAKE PEDAL .......................................................... 3-30
ADJUSTING THE PARKING BRAKE......................................................3-31
CHECKING THE BRAKE FLUID LEVEL.................................................3-32
CHECKING THE FRONT BRAKE PADS ................................................ 3-33
CHECKING THE REAR BRAKE PADS ..................................................3-34
CHECKING THE PARKING BRAKE PADS ............................................ 3-34
CHECKING THE BRAKE HOSES AND BRAKE PIPES ......................... 3-35
BLEEDING THE HYDRAULIC BRAKE SYSTEM ...................................3-36
ADJUSTING THE SELECT LEVER SHIFT ROD....................................3-37
ADJUSTING THE BRAKE LIGHT SWITCH ............................................ 3-38
CHECKING THE FINAL GEAR OIL LEVEL ............................................ 3-38
CHANGING THE FINAL GEAR OIL........................................................3-39
CHECKING THE DIFFERENTIAL GEAR OIL.........................................3-40
CHANGING THE DIFFERENTIAL GEAR OIL ........................................3-41
CHECKING THE CONSTANT VELOCITY JOINT DUST BOOTS .......... 3-43
CHECKING THE STEERING SYSTEM .................................................. 3-43
ADJUSTING THE TOE-IN.......................................................................3-44
ADJUSTING THE FRONT SHOCK ABSORBERS .................................3-45
ADJUSTING THE REAR SHOCK ABSORBERS....................................3-48
CHECKING THE TIRES..........................................................................3-51
CHECKING THE WHEELS .....................................................................3-53
CHECKING AND LUBRICATING THE CABLES ....................................3-54
LUBRICATING THE PEDAL, ETC. .........................................................3-54
ELECTRICAL SYSTEM.................................................................................3-55
CHECKING AND CHARGING THE BATTERY.......................................3-55
CHECKING THE FUSES ........................................................................3-61
ADJUSTING THE HEADLIGHT BEAMS.................................................3-64
CHANGING THE HEADLIGHT BULBS...................................................3-64
CHANGING THE TAIL/BRAKE LIGHT BULB .........................................3-65
CHAPTER 4
ENGINE
ENGINE REMOVAL ........................................................................................4-1
V-BELT COOLING DUCTS, MUFFLER AND EXHAUST PIPES..............4-1
INSTALLING THE V-BELT COOLING DUCTS.........................................4-4
SHIFT ARM ...............................................................................................4-5
HOSES AND LEADS................................................................................. 4-6
ENGINE MOUNTING BOLTS ...................................................................4-8
INSTALLING THE ENGINE.....................................................................4-10
CYLINDER HEAD..........................................................................................4-11
REMOVING THE CYLINDER HEAD.......................................................4-14
CHECKING THE CAMSHAFT SPROCKET............................................4-15
CHECKING THE TAPPET COVERS ...................................................... 4-15
CHECKING THE TIMING CHAIN TENSIONER......................................4-15
CHECKING THE CYLINDER HEAD ....................................................... 4-16
INSTALLING THE CYLINDER HEAD .....................................................4-17
ROCKER ARMS AND CAMSHAFT ..............................................................4-20
REMOVING THE ROCKER ARMS AND CAMSHAFT............................4-22
CHECKING THE CAMSHAFT.................................................................4-22
CHECKING THE DECOMPRESSION SYSTEM..................................... 4-23
CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS ........4-23
INSTALLING THE CAMSHAFT AND ROCKER ARMS .......................... 4-24
VALVES AND VALVE SPRINGS..................................................................4-27
REMOVING THE VALVES AND VALVE SPRINGS ...............................4-28
CHECKING THE VALVES AND VALVE SPRINGS ................................4-29
INSTALLING THE VALVES AND VALVE SPRINGS ..............................4-33
CYLINDER AND PISTON..............................................................................4-36
REMOVING THE PISTON ......................................................................4-37
CHECKING THE CYLINDER AND PISTON ........................................... 4-37
CHECKING THE PISTON RINGS...........................................................4-39
CHECKING THE PISTON PIN ................................................................4-40
INSTALLING THE PISTON AND CYLINDER .........................................4-41
AC MAGNETO...............................................................................................4-44
REMOVING THE AC MAGNETO ROTOR..............................................4-47
CHECKING THE STATOR COIL AND CRANKSHAFT POSITION
SENSOR ................................................................................................4-48
CHECKING THE STARTER CLUTCH .................................................... 4-48
CHECKING THE TORQUE LIMITER......................................................4-49
INSTALLING THE AC MAGNETO ROTOR ............................................4-49
BALANCER GEARS AND OIL PUMP GEARS ............................................ 4-51
REMOVING THE BALANCER DRIVEN GEAR AND OIL PUMP
DRIVEN GEAR.......................................................................................4-53
CHECKING THE OIL PUMP DRIVE ....................................................... 4-53
CHECKING THE BALANCER DRIVE .....................................................4-53
INSTALLING THE BALANCER DRIVE GEAR, BALANCER DRIVEN
GEAR, AND OIL PUMP DRIVEN GEAR................................................4-54
PRIMARY AND SECONDARY SHEAVES....................................................4-55
PRIMARY SHEAVE................................................................................. 4-57
SECONDARY SHEAVE ..........................................................................4-58
REMOVING THE PRIMARY AND SECONDARY SHEAVES ................. 4-59
DISASSEMBLING THE SECONDARY SHEAVE.................................... 4-59
CHECKING THE PRIMARY SHEAVE ....................................................4-60
CHECKING THE SECONDARY SHEAVE ..............................................4-60
ASSEMBLING THE PRIMARY SHEAVE ................................................ 4-61
ASSEMBLING THE SECONDARY SHEAVE.......................................... 4-62
INSTALLING THE PRIMARY AND SECONDARY SHEAVES................ 4-64
CLUTCH ........................................................................................................4-65
REMOVING THE CLUTCH .....................................................................4-67
CHECKING THE CLUTCH......................................................................4-68
INSTALLING THE CLUTCH....................................................................4-69
CRANKCASE ................................................................................................4-70
TIMING CHAIN AND OIL FILTER ........................................................... 4-70
CRANKCASE ..........................................................................................4-72
CRANKCASE BEARINGS....................................................................... 4-73
SEPARATING THE CRANKCASE..........................................................4-74
CHECKING THE TIMING CHAIN AND GUIDE.......................................4-74
CHECKING THE RELIEF VALVE ...........................................................4-74
CHECKING THE BEARINGS..................................................................4-75
CHECKING THE CRANKCASE ..............................................................4-75
ASSEMBLING THE CRANKCASE..........................................................4-75
INSTALLING THE SHIFT LEVER ........................................................... 4-76
CRANKSHAFT AND OIL PUMP ...................................................................4-77
OIL PUMP ...............................................................................................4-78
REMOVING THE CRANKSHAFT ...........................................................4-79
CHECKING THE OIL PUMP ...................................................................4-79
CHECKING THE OIL STRAINER ...........................................................4-80
CHECKING THE CRANKSHAFT ............................................................ 4-80
ASSEMBLING THE OIL PUMP...............................................................4-81
INSTALLING THE CRANKSHAFT .......................................................... 4-81
TRANSMISSION............................................................................................4-83
DRIVE AXLE ...........................................................................................4-85
REMOVING THE TRANSMISSION ........................................................4-87
CHECKING THE SHIFT FORKS.............................................................4-87
CHECKING THE SHIFT DRUM .............................................................. 4-88
CHECKING THE TRANSMISSION .........................................................4-88
CHECKING THE SECONDARY SHAFT.................................................4-89
ASSEMBLING THE SHIFT FORK ASSEMBLY ...................................... 4-89
INSTALLING THE TRANSMISSION ....................................................... 4-89
MIDDLE GEAR ..............................................................................................4-91
MIDDLE DRIVE SHAFT ..........................................................................4-91
MIDDLE DRIVEN SHAFT........................................................................4-92
REMOVING THE MIDDLE DRIVE SHAFT .............................................4-94
REMOVING THE MIDDLE DRIVEN SHAFT...........................................4-95
CHECKING THE PINION GEARS ..........................................................4-98
SELECTING MIDDLE DRIVE AND DRIVEN GEAR SHIMS...................4-98
INSTALLING THE BEARING AND OIL SEALS .................................... 4-102
INSTALLING THE MIDDLE DRIVEN SHAFT .......................................4-103
INSTALLING THE MIDDLE DRIVE SHAFT .......................................... 4-105
MEASURING THE MIDDLE GEAR BACKLASH................................... 4-106
CHAPTER 5
COOLING SYSTEM
RADIATOR AND COOLANT RESERVOIR ....................................................5-1
CHECKING THE RADIATOR....................................................................5-3
INSTALLING THE RADIATOR..................................................................5-4
THERMOSTAT ................................................................................................5-5
CHECKING THE THERMOSTAT..............................................................5-6
INSTALLING THE THERMOSTAT............................................................5-6
WATER PUMP.................................................................................................5-7
DISASSEMBLING THE WATER PUMP.................................................... 5-9
CHECKING THE WATER PUMP .............................................................. 5-9
ASSEMBLING THE WATER PUMP........................................................5-10
OIL COOLER.................................................................................................5-12
CHECKING THE OIL COOLER ..............................................................5-14
CHAPTER 6
FUEL INJECTION SYSTEM
FUEL INJECTION SYSTEM............................................................................6-1
CIRCUIT DIAGRAM ..................................................................................6-2
ECU SELF-DIAGNOSTIC FUNCTION......................................................6-4
SELF-DIAGNOSTIC FUNCTION TABLE ..................................................6-5
TROUBLESHOOTING CHART ................................................................. 6-6
DIAGNOSTIC MODE ................................................................................6-7
TROUBLESHOOTING DETAILS ............................................................6-11
CHECKING THE INTAKE AIR PRESSURE SENSOR ...........................6-26
CHECKING THE INTAKE AIR TEMPERATURE SENSOR ....................6-26
AIR FILTER CASE AND AIR INTAKE DUCT ...............................................6-28
INSTALLING THE AIR INTAKE DUCT AND AIR FILTER CASE............ 6-31
FUEL PUMP AND FUEL TANK ....................................................................6-32
REMOVING THE FUEL TANK ................................................................6-34
REMOVING THE FUEL PUMP ...............................................................6-34
CHECKING THE FUEL PUMP BODY.....................................................6-35
CHECKING THE ROLLOVER VALVE .................................................... 6-35
INSTALLING THE FUEL PUMP..............................................................6-35
INSTALLING THE FUEL HOSE ..............................................................6-36
THROTTLE BODY.........................................................................................6-37
REMOVING THE THROTTLE BODY ASSEMBLY ................................. 6-40
CHECKING THE FUEL INJECTOR ........................................................ 6-40
CHECKING THE THROTTLE BODY ...................................................... 6-40
INSTALLING THE THROTTLE BODY ASSEMBLY................................6-41
CHECKING THE FUEL PUMP AND PRESSURE REGULATOR
OPERATION ..........................................................................................6-43
CHECKING AND ADJUSTING THE THROTTLE POSITION
SENSOR .................................................................................................6-44
CHAPTER 7
DRIVE TRAIN
TROUBLESHOOTING.....................................................................................7-1
CHECKING NOISES .................................................................................7-1
TROUBLESHOOTING CHART ................................................................. 7-3
FRONT CONSTANT VELOCITY JOINTS, DIFFERENTIAL GEAR AND
DRIVE SHAFT ................................................................................................7-4
DISASSEMBLING THE FRONT CONSTANT VELOCITY JOINTS ........7-10
DISASSEMBLING THE UNIVERSAL JOINT .......................................... 7-11
REMOVING THE DIFFERENTIAL GEAR ASSEMBLY........................... 7-11
CHECKING THE FRONT CONSTANT VELOCITY JOINTS...................7-12
CHECKING THE DIFFERENTIAL GEARS ............................................. 7-12
CHECKING THE DIFFERENTIAL GEAR MOTOR ................................. 7-13
ASSEMBLING THE FRONT CONSTANT VELOCITY JOINTS .............. 7-13
ASSEMBLING THE DIFFERENTIAL GEARS.........................................7-15
ASSEMBLING THE UNIVERSAL JOINT ................................................ 7-17
MEASURING THE DIFFERENTIAL GEAR LASH ..................................7-17
ADJUSTING THE DIFFERENTIAL GEAR LASH....................................7-18
CHECKING THE DIFFERENTIAL GEAR OPERATION .........................7-19
REAR CONSTANT VELOCITY JOINTS, FINAL DRIVE GEAR AND
DRIVE SHAFT ..............................................................................................7-20
DISASSEMBLING THE REAR CONSTANT VELOCITY JOINTS........... 7-28
ASSEMBLING THE REAR CONSTANT VELOCITY JOINTS................. 7-29
DISASSEMBLING THE FINAL GEAR CASE..........................................7-31
REMOVING THE FINAL DRIVE ROLLER BEARINGS...........................7-32
INSTALLING THE FINAL DRIVE ROLLER BEARINGS ......................... 7-32
POSITIONING THE FINAL DRIVE PINION GEAR AND RING
GEAR .....................................................................................................7-33
CHECKING THE DRIVE SHAFT.............................................................7-38
CHECKING THE FINAL GEAR CASE .................................................... 7-38
MEASURING AND ADJUSTING THE FINAL GEAR LASH....................7-38
ASSEMBLING THE FINAL GEAR CASE................................................7-40
CHAPTER 8
CHASSIS
SEATS, ENCLOSURE, HOOD AND CARGO BED ........................................ 8-1
FRONT GUARD AND HOOD....................................................................8-1
SEATS, REAR CONSOLE AND INSTRUMENT PANELS........................8-2
REMOVING THE STEERING WHEEL......................................................8-4
INSTALLING THE STEERING WHEEL .................................................... 8-4
SIDE DOORS ............................................................................................8-5
PANELS AND FRONT CONSOLE............................................................8-6
REMOVING THE SIDE PANELS ..............................................................8-8
INSTALL THE SIDE PANELS ...................................................................8-8
CARGO BED .............................................................................................8-9
SKID PLATES .........................................................................................8-11
INSTALLING THE REAR SKID PLATE...................................................8-12
ENCLOSURE AND SEAT BELTS...........................................................8-13
INSTALLING THE ENCLOSURE ............................................................ 8-14
FRONT AND REAR WHEELS ......................................................................8-15
FRONT WHEELS ....................................................................................8-15
REAR WHEELS ......................................................................................8-17
CHECKING THE WHEELS .....................................................................8-19
CHECKING THE WHEEL HUBS.............................................................8-19
CHECKING THE BRAKE DISCS ............................................................8-20
INSTALLING THE WHEEL HUBS...........................................................8-20
INSTALLING THE WHEELS ...................................................................8-20
FRONT AND REAR BRAKES.......................................................................8-21
FRONT BRAKE PADS ............................................................................8-21
REAR BRAKE PADS...............................................................................8-22
REPLACING THE FRONT AND REAR BRAKE PADS........................... 8-23
BRAKE MASTER CYLINDER ................................................................. 8-25
CHECKING THE MASTER CYLINDER .................................................. 8-27
ASSEMBLING THE BRAKE MASTER CYLINDER.................................8-27
INSTALLING THE BRAKE MASTER CYLINDER ...................................8-28
FRONT BRAKE CALIPER.......................................................................8-30
REAR BRAKE CALIPERS.......................................................................8-32
DISASSEMBLING THE FRONT AND REAR BRAKE CALIPERS ..........8-34
CHECKING THE FRONT AND REAR BRAKE CALIPERS ....................8-34
ASSEMBLING THE FRONT AND REAR BRAKE CALIPERS ................8-35
INSTALLING THE FRONT AND REAR BRAKE CALIPERS ..................8-36
PARKING BRAKE.........................................................................................8-38
PARKING BRAKE PADS ........................................................................8-38
REPLACING THE PARKING BRAKE PADS ..........................................8-39
PARKING BRAKE ...................................................................................8-40
PARKING BRAKE DISC.......................................................................... 8-43
CHECKING THE PARKING BRAKE ....................................................... 8-44
CHECKING THE PARKING BRAKE DISC .............................................8-44
ASSEMBLING THE PARKING BRAKE...................................................8-44
PEDAL ASSEMBLY ......................................................................................8-47
STEERING SYSTEM.....................................................................................8-49
STEERING SHAFT AND STEERING ASSEMBLY ................................. 8-49
DISASSEMBLING THE STEERING ASSEMBLY ................................... 8-52
CHECKING THE STEERING JOINT.......................................................8-52
CHECKING THE STEERING ASSEMBLY.............................................. 8-52
ASSEMBLING THE STEERING ASSEMBLY ......................................... 8-53
INSTALLING THE STEERING SYSTEM ................................................ 8-54
TIE-ROD AND STEERING KNUCKLE....................................................8-55
REMOVING THE STEERING KNUCKLES .............................................8-56
CHECKING THE TIE-RODS ...................................................................8-56
CHECKING THE STEERING KNUCKLES..............................................8-56
FRONT ARMS AND FRONT SHOCK ABSORBERS ...................................8-60
REMOVING THE FRONT ARMS ............................................................8-62
CHECKING THE FRONT ARMS.............................................................8-62
HANDLING THE FRONT SHOCK ABSORBERS AND GAS CYLINDERS
(For models equipped with gas-oil damper shock absorbers)................8-64
DISPOSING OF A FRONT SHOCK ABSORBER AND GAS CYLINDER
(For models equipped with gas-oil damper shock absorbers)................8-65
CHECKING THE FRONT SHOCK ABSORBERS...................................8-65
INSTALLING THE FRONT ARMS AND FRONT SHOCK
ABSORBER............................................................................................ 8-66
REAR KNUCKLE AND STABILIZER ...........................................................8-67
CHECKING THE REAR KNUCKLES ......................................................8-68
CHECKING THE STABILIZER................................................................8-68
REAR ARMS AND REAR SHOCK ABSORBER..........................................8-69
CHECKING THE REAR ARMS ............................................................... 8-71
HANDLING THE REAR SHOCK ABSORBERS AND GAS CYLINDERS
(For models equipped with gas-oil damper shock absorbers)................8-71
DISPOSING OF A REAR SHOCK ABSORBER AND GAS CYLINDER
(For models equipped with gas-oil damper shock absorbers)................8-72
CHECKING THE REAR SHOCK ABSORBERS ..................................... 8-72
INSTALLING THE REAR ARMS AND REAR SHOCK ABSORBER.......8-73
CHAPTER 9
ELECTRICAL
ELECTRICAL COMPONENTS........................................................................9-1
CHECKING SWITCH CONTINUITY................................................................9-3
CHECKING THE SWITCHES..........................................................................9-4
CHECKING THE BULBS AND BULB SOCKETS ..........................................9-6
TYPES OF BULBS ....................................................................................9-6
CHECKING THE CONDITION OF THE BULBS ....................................... 9-7
CHECKING THE CONDITION OF THE BULB SOCKETS .......................9-8
IGNITION SYSTEM .........................................................................................9-9
CIRCUIT DIAGRAM ..................................................................................9-9
TROUBLESHOOTING ............................................................................9-10
ELECTRIC STARTING SYSTEM ..................................................................9-14
CIRCUIT DIAGRAM ................................................................................9-14
STARTING CIRCUIT OPERATION.........................................................9-15
TROUBLESHOOTING ............................................................................9-16
STARTER MOTOR........................................................................................9-19
CHECKING THE STARTER MOTOR ..................................................... 9-21
ASSEMBLING THE STARTER MOTOR.................................................9-23
CHARGING SYSTEM....................................................................................9-24
CIRCUIT DIAGRAM ................................................................................9-24
TROUBLESHOOTING ............................................................................9-25
LIGHTING SYSTEM ......................................................................................9-27
CIRCUIT DIAGRAM ................................................................................9-27
TROUBLESHOOTING ............................................................................9-28
CHECKING THE LIGHTING SYSTEM.................................................... 9-30
SIGNALING SYSTEM ...................................................................................9-32
CIRCUIT DIAGRAM ................................................................................9-32
TROUBLESHOOTING ............................................................................9-34
CHECKING THE SIGNALING SYSTEM ................................................. 9-36
COOLING SYSTEM.......................................................................................9-45
CIRCUIT DIAGRAM ................................................................................9-45
TROUBLESHOOTING ............................................................................9-46
FUEL PUMP SYSTEM...................................................................................9-50
CIRCUIT DIAGRAM ................................................................................9-50
TROUBLESHOOTING ............................................................................9-51
2WD/4WD SELECTING SYSTEM.................................................................9-53
CIRCUIT DIAGRAM ................................................................................9-53
TROUBLESHOOTING ............................................................................9-54
CHAPTER 10
TROUBLESHOOTING
STARTING FAILURE/HARD STARTING .....................................................10-1
FUEL SYSTEM........................................................................................10-1
ELECTRICAL SYSTEM........................................................................... 10-1
COMPRESSION SYSTEM......................................................................10-2
POOR IDLE SPEED PERFORMANCE ......................................................... 10-2
POOR IDLE SPEED PERFORMANCE...................................................10-2
POOR MEDIUM AND HIGH-SPEED PERFORMANCE................................ 10-2
POOR MEDIUM AND HIGH-SPEED PERFORMANCE .........................10-2
FAULTY DRIVE TRAIN.................................................................................10-3
FAULTY GEAR SHIFTING............................................................................10-4
HARD SHIFTING.....................................................................................10-4
SHIFT LEVER DOES NOT MOVE .......................................................... 10-4
JUMPS OUT OF GEAR...........................................................................10-4
FAULTY CLUTCH PERFORMANCE ............................................................ 10-4
ENGINE OPERATES BUT VEHICLE WILL NOT MOVE ........................ 10-4
CLUTCH SLIPPING ................................................................................10-4
POOR STARTING PERFORMANCE......................................................10-4
POOR SPEED PERFORMANCE............................................................10-5
OVERHEATING.............................................................................................10-5
OVERHEATING ......................................................................................10-5
OVERCOOLING ............................................................................................10-5
COOLING SYSTEM ................................................................................ 10-5
FAULTY BRAKE ...........................................................................................10-5
POOR BRAKING EFFECT......................................................................10-5
SHOCK ABSORBER MALFUNCTION .........................................................10-6
MALFUNCTION....................................................................................... 10-6
UNSTABLE HANDLING................................................................................10-6
UNSTABLE HANDLING ..........................................................................10-6
LIGHTING SYSTEM ......................................................................................10-6
HEADLIGHT DOES NOT COME ON ...................................................... 10-6
BULB BURNT OUT ................................................................................. 10-6
VEHICLE IDENTIFICATION
EBS00009
GENERAL INFORMATION
VEHICLE IDENTIFICATION
EBS00010
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number 1 is
stamped into the frame.
EBS00011
MODEL LABEL
1
The model label 1 is affixed to the frame
under the driver seat. Record the information
on this label in the space provided. This information will be needed to order spare parts.
GEN
INFO
1 - 1
GEN
FEATURES
EAS20170
FEATURES
OUTLINE OF THE FI SYSTEM
The main function of a fuel supply system is to provide fuel to the combustion chamber at the optimum air-fuel ratio in accordance with the engine operating conditions and the atmospheric temperature. In the conventional carburetor system, the air-fuel ratio of the mixture that is supplied to the
combustion chamber is created by the volume of the intake air and the fuel that is metered by the jet
used in the respective carburetor.
Despite the same volume of intake air, the fuel volume requirement varies with the engine operating
conditions, such as acceleration, deceleration, or operating under a heavy load. Carburetors that
meter the fuel through the use of jets have been provided with various auxiliary devices, so that an
optimum air-fuel ratio can be achieved to accommodate the constant changes in the operating conditions of the engine.
As the requirements for the engine to deliver more performance and cleaner exhaust gases
increase, it becomes necessary to control the air-fuel ratio in a more precise and finely tuned manner. To accommodate this need, this model has adopted an electronically controlled fuel injection
(FI) system, in place of the conventional carburetor system. This system can achieve an optimum
air-fuel ratio required by the engine at all times by using a microprocessor that regulates the fuel
injection volume according to the engine operating conditions detected by various sensors.
The adoption of the FI system has resulted in a highly precise fuel supply, improved engine
response, better fuel economy, and reduced exhaust emissions.
INFO
1
Fuel injection system relay
1
ECU (engine control unit)
2
Lean angle sensor
3
Engine trouble warning light
4
Intake air temperature sensor
5
TPS (throttle position sensor)
6
Intake air pressure sensor
7
Spark plug
8
7654321
8
90ABCDE
Coolant temperature sensor
9
Fuel injector
0
ISC (idle speed control) unit
A
Fuel pump
B
Crankshaft position sensor
C
Ignition coil
D
Speed sensor
E
1 - 2
GEN
FEATURES
FI SYSTEM
The fuel pump delivers fuel to the fuel injector via the fuel filter. The pressure regulator maintains
the fuel pressure that is applied to the fuel injector at only 324 kPa (3.24 kg/cm
ingly, when the energizing signal from the ECU energizes the fuel injector, the fuel passage opens,
causing the fuel to be injected into the intake manifold only during the time the passage remains
open. Therefore, the longer the length of time the fuel injector is energized (injection duration), the
greater the volume of fuel that is supplied. Conversely, the shorter the length of time the fuel injector
is energized (injection duration), the lesser the volume of fuel that is supplied.
The injection duration and the injection timing are controlled by the ECU. Signals that are input from
the throttle position sensor, crankshaft position sensor, intake air pressure sensor, intake air temperature sensor, coolant temperature sensor, lean angle sensor and speed sensor enable the ECU
to determine the injection duration. The injection timing is determined through the signals from the
crankshaft position sensor. As a result, the volume of fuel that is required by the engine can be supplied at all times in accordance with the driving conditions.
Illustration is for reference only.
INFO
2
, 46.1 psi). Accord-
D
Fuel pump
1
Fuel injector
2
Ignition coil
3
ECU (engine control unit)
4
Speed sensor
5
Lean angle sensor
6
Coolant temperature sensor
7
Crankshaft position sensor
8
Intake air pressure sensor
9
Throttle body
0
1
C
É
B
9
È
A
0
2
Ê
4
5
6
7
3
8
ISC (idle speed control) unit
A
Throttle position sensor
B
Intake air temperature sensor
C
Air intake duct
D
Fuel system
È
Air system
É
Control system
Ê
1 - 3
8
7
12
56
3
4
GEN
FEATURES
INSTRUMENT FUNCTIONS
5B410004
Multi-function meter unit
Speedometer
1
Fuel meter
2
“H” button
3
“M” button
4
Clock/Hour meter/Voltage display
5
Odometer/Tripmeter A/Tripmeter B
6
“TRIP/ODO” button
7
Clock/Hour button “ / ”
8
The multi-function meter unit is equipped with
the following:
• a speedometer (which shows the riding
speed)
• an odometer (which shows the total distance traveled)
• two tripmeters (which show the distance
traveled since they were last set to zero)
• a clock
• an hour meter (which shows the total time
the engine has been running)
• a voltage display (which shows the battery
voltage)
• a fuel meter
• a self-diagnosis device
INFO
2
1
Odometer and tripmeter modes
Odometer/Tripmeter A/Tripmeter B
1
“TRIP/ODO” button
2
Pushing the “TRIP/ODO” button switches the
display between the odometer mode “ODO”
and the tripmeter modes “A” and “B” in the following order:
ODO → TRIP A → TRIP B → ODO
To reset a tripmeter, select it by pushing the
“TRIP/ODO” button, and then hold the “TRIP/
ODO” button for at least three seconds. The
tripmeters can be used to estimate the distance that can be traveled with a full tank of
fuel. This information will enable you to plan
future fuel stops.
Pushing and holding in the “TRIP/ODO” button, and turning the key to “ON” while the button is pushed, switches the display between
“mph” and “km/h”.
1 - 4
1
4
2
3
GEN
FEATURES
Clock and voltage display modes
1 Clock/Hour button “ / ”
2 “H” button
3 “M” button
4 Clock/Hour meter/Voltage display
Pushing the “ / ” button switches the display between the clock mode “CLOCK”, the
hour meter mode “HOUR”, and the voltage display mode “btry” in the following order:
CLOCK → HOUR → btry → CLOCK
To set the clock
1. Set the display to the clock.
2. Push the “ / ” button until the clock
starts flashing.
3. Set the hours by pushing the “H” button.
4. Set the minutes by pushing the “M” button.
5. Push the “ / ” button, and then
release it to start the clock.
INFO
Voltage display mode
This display shows the battery voltage. “btry”
appears for 1 second when the voltage display
mode is first selected, and then the battery
voltage is shown.
If the battery voltage is less than 10 volts, “LO”
is displayed and if the voltage is above 16
volts, “HI” is displayed.
TIP:
“LO” or “HI” is displayed only if the low or high
battery voltage is detected for 16 seconds or
more.
NOTICE
If the voltage display indicates “LO” or “HI”,
there may be trouble with the battery charging
circuit or the battery may be faulty. If “LO” or
“HI” appears in the display, check the vehicle.
1 - 5
FEATURES
GEN
INFO
1
1
2
3
Fuel meter
1 Fuel level warning indicator
2 Fuel meter
3 “E” segment
The fuel meter indicates the amount of fuel in
the fuel tank. The display segments of the fuel
meter disappear from “F” (full) towards “E”
(empty) as the fuel level decreases. When the
“E” segment disappears and the fuel level
warning indicator flashes, refuel as soon as
possible.
TIP:
This fuel meter is equipped with a self-diagnosis system. If the electrical circuit is defective,
all the display segments and fuel level warning
indicator will start flashing. If this occurs, check
the electrical circuit.
Self-diagnosis device
1 Error code display
This model is equipped with a self-diagnosis
device for various electrical circuits.
If any of those circuits are defective, the
engine trouble warning light will come on or
flash, and then the multi-function display will
indicate a two-digit error code.
If the multi-function display indicates such an
error code, note the code number, and check
the vehicle.
NOTICE
If the multi-function display indicates an error
code, the vehicle should be checked as soon
as possible in order to avoid engine damage.
1 - 6
IMPORTANT INFORMATION
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.
GEN
INFO
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.
1 - 7
IMPORTANT INFORMATION
EBS00016
LOCK WASHERS/PLATES AND COTTER
PINS
After removal, replace all lock washers/plates
1
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.
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
1
GEN
INFO
NOTICE
_
Do not spin the bearing with compressed
air because this will damage the bearing
surfaces.
Bearing
1
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 1, make sure the
sharp-edged corner 2 is positioned opposite
the thrust 3 that the circlip receives.
Shaft
4
1 - 8
IMPORTANT INFORMATION
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.
TIP:
_
If the pin 1 on the terminal is flattened, bend it
up.
GEN
INFO
4. Connect:
• lead
• coupler
• connector
TIP:
_
Make sure all connections are tight.
5. Check:
• continuity (with the pocket tester)
Pocket tester
90890-03112
Analog pocket tester
YU-03112-C
TIP:
_
• 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 - 9
GEN
SPECIAL TOOLS
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 CDN
P/N. YM-, YU-, YS-, YK-, ACC-
Except for US and CDN
P/N. 90890-
Tool No. Tool name/How to use Illustration
Slide hammer bolt
Slide hammer bolt 6 mm
90890-01083
YU-01083-1
This tool is used to remove the rocker
arm shaft.
INFO
90890-01084
YU-01083-3
90890-01135
YU-01135-B
90890-01229
YM-01229
Weight
YU-01083-3
This tool is used to remove the rocker
arm shaft.
Crankcase separating tool
Crankcase separator
This tool is used to separate the crankcase.
Coupling gear/middle shaft tool
Gear holder
This tool is needed when removing or
installing the coupling gear nut.
Valve spring compressor attachment
90890-01243
YM-01253-1
Valve spring compressor adapter
(26 mm)
This tool is needed to remove and install
the valve assemblies.
1 - 10
GEN
SPECIAL TOOLS
Tool No. Tool name/How to use Illustration
Ring nut wrench
Spanner wrench
90890-01268
YU-01268
This tool is used to loosen or tighten the
front and rear shock absorber locknuts.
Crankshaft installer pot
90890-01274
YU-90058
YU-90058/YU-90059
This tool is used to install the crankshaft.
Crankshaft installer bolt
Bolt
90890-01275
YU-90060
INFO
90890-01304
YU-01304
90890-01309
YU-90059
This tool is used to install the crankshaft.
Piston pin puller set
Piston pin puller
This tool is used to remove the piston pin.
Spacer
Pot spacer
This tool is used to install the crankshaft.
Tappet adjusting tool
Six piece tappet set
YU-01304
ø35
90890-01311
YM-A5970
This tool is necessary for adjusting the
valve clearance.
YM-A5970
ø9ø8 ø10
ø3 ø4
1 - 11
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