VMX12N(C)

SERVICEMANUAL

LIT-11616-14-12

5GK-28197-E0

EAS00000

VMX12N(C)

SERVICE MANUAL

© 2000 by Yamaha Motor Corporation, U.S.A.

First edition, June 2000

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.

P/N LIT-11616-14-12

EAS00003

NOTICE

This manual was produced by the Yamaha Motor Company, Ltd. primarily for use by Yamaha deal-

ers and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in

one manual. Therefore, anyone who uses this book to perform maintenance and repairs on Yamaha

vehicles should have a basic understanding of mechanics and the techniques to repair these types

of vehicles. Repair and maintenance work attempted by anyone without this knowledge is 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 of its models. Modifications and

significant changes in specifications or procedures will be forwarded to all authorized Yamaha deal-

ers and will appear in future editions of this manual where applicable.

NOTE:

@

• 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.

@@

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IMPORTANT MANUAL INFORMATION

Particularly important information is distinguished in this manual by the following.

The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR

SAFETY IS INVOLVED!

Failure to follow WARNING instructions could result in severe injury or death to

the motorcycle operator, a bystander or a person checking or repairing the

motorcycle.

A CAUTION indicates special precautions that must be taken to avoid damage

to the motorcycle.

A NOTE provides key information to make procedures easier or clearer.

WARNING

CAUTION:

NOTE:

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HOW TO USE THIS MANUAL

This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive

explanations of all installation, removal, disassembly, assembly, repair and check procedures are

laid out with the individual steps in sequential order.

1 The manual is divided into chapters. An abbreviation and symbol in the upper right corner of

each page indicate the current chapter.

Refer to “SYMBOLS”.

2 Each chapter is divided into sections. The current section title is shown at the top of each page,

except in chapter 3 (“PERIODIC CHECKS AND ADJUSTMENTS”), where the sub-section title(s)

appears.

3 Sub-section titles appear in smaller print than the section title.

4 To help identify parts and clarify procedure steps, there are exploded diagrams at the start of

each removal and disassembly section.

5 Numbers are given in the order of the jobs in the exploded diagram. A circled number indicates a

disassembly step.

6 Symbols indicate parts to be lubricated or replaced.

Refer to “SYMBOLS”.

7 A job instruction chart accompanies the exploded diagram, providing the order of jobs, names of

parts, notes in jobs, etc.

8 Jobs requiring more information (such as special tools and technical data) are described sequen-

tially.

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SYMBOLS

The following symbols are not relevant to

every vehicle.

Symbols 1 to 9 indicate the subject of each

chapter.

1 General information

2 Specifications

3 Periodic checks and adjustments

4 Engine

5 Cooling system

6 Carburetion

7 Chassis

8 Electrical system

9 Troubleshooting

Symbols 0 to G indicate the following.

0 Serviceable with engine mounted

A Filling fluid

B Lubricant

C Special tool

D Tightening torque

E Wear limit, clearance

F Engine speed

G Electrical data

Symbols H to M in the exploded diagrams

indicate the types of lubricants and lubrication

points.

H Engine oil

I Gear oil

J Molybdenum disulfide oil

K Wheel bearing grease

L Lithium soap base grease

M Molybdenum disulfide grease

Symbols N to O in the exploded diagrams

indicate the following.

N Apply locking agent (LOCTITE^®)

O Replace the part

1

2

3

4

5

6

7

8

9

0

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

GEN

INFO

SPEC

CHK

ADJ

ENG

COOL

CARB

CHAS

–

+

ELEC

TRBL

SHTG

T R

.

.

E

G

M

B

LS

M

LT

New

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TABLE OF CONTENTS

GENERAL INFORMATION

GEN

INFO 1

SPECIFICATIONS

SPEC 2

PERIODIC CHECKS AND

ADJUSTMENTS

CHK

ADJ 3

ENGINE

ENG 4

COOLING SYSTEM

COOL 5

CARBURETION

CARB 6

CHASSIS

CHAS 7

ELECTRICAL SYSTEM

ELEC 8

TROUBLESHOOTING

TRBL

SHTG 9

–

+

CONTENTS

CHAPTER 1.

GENERAL INFORMATION

MOTORCYCLE IDENTIFICATION .................................................................1-1

VEHICLE IDENTIFICATION NUMBER ....................................................1-1

MODEL CODE ..........................................................................................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 ....................................1-3

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 ..........................................................................2-2

CHASSIS SPECIFICATIONS .......................................................................2-12

ELECTRICAL SPECIFICATIONS ................................................................2-15

CONVERSION TABLE .................................................................................2-18

GENERAL TIGHTENING TORQUE SPECIFICATIONS ...............................2-18

TIGHTENING TORQUES .............................................................................2-19

ENGINE TIGHTENING TORQUES ........................................................2-19

CHASSIS TIGHTENING TORQUES ......................................................2-22

LUBRICATION POINTS AND LUBRICANT TYPES ....................................2-24

ENGINE ..................................................................................................2-24

CHASSIS ...............................................................................................2-25

GEN

INFO 1

SPEC 2

CHK

ADJ 3

ENG 4

COOL 5

CARB 6

CHAS 7

ELEC 8

TRBL

SHTG 9

–

+

COOLING SYSTEM DIAGRAMS .................................................................2-26

OIL FLOW DIAGRAMS ................................................................................2-28

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

SEATS AND SIDE COVERS ..........................................................................3-4

TOP COVER AND COVERS ..........................................................................3-5

AIR FILTER CASE AND ELECTRICAL COMPONENTS BOARD ................3-6

ENGINE ...........................................................................................................3-7

ADJUSTING THE VALVE CLEARANCE ..................................................3-7

SYNCHRONIZING THE CARBURETORS .............................................3-12

ADJUSTING THE ENGINE IDLING SPEED ..........................................3-14

ADJUSTING THE THROTTLE CABLE FREE PLAY ..............................3-15

CHECKING THE SPARK PLUGS ..........................................................3-16

CHECKING THE IGNITION TIMING ......................................................3-17

MEASURING THE COMPRESSION PRESSURE .................................3-18

CHECKING THE ENGINE OIL LEVEL ...................................................3-20

CHANGING THE ENGINE OIL ...............................................................3-21

MEASURING THE ENGINE OIL PRESSURE .......................................3-22

CHECKING THE CLUTCH FLUID LEVEL .............................................3-24

BLEEDING THE HYDRAULIC CLUTCH SYSTEM ................................3-25

CLEANING THE AIR FILTER ELEMENT ...............................................3-26

CHECKING THE CARBURETOR JOINTS .............................................3-27

CHECKING THE VACUUM HOSES ......................................................3-27

CHECKING THE FUEL HOSES AND FUEL FILTER .............................3-28

CHECKING THE CRANKCASE BREATHER HOSE ..............................3-28

CHECKING THE EXHAUST SYSTEM ...................................................3-29

CHECKING THE COOLANT LEVEL ......................................................3-29

CHECKING THE COOLING SYSTEM ...................................................3-30

CHANGING THE COOLANT ..................................................................3-30

CHASSIS ......................................................................................................3-33

ADJUSTING THE FRONT BRAKE .........................................................3-33

ADJUSTING THE REAR BRAKE ...........................................................3-34

CHECKING THE BRAKE FLUID LEVEL ................................................3-35

CHECKING THE BRAKE PADS .............................................................3-36

ADJUSTING THE REAR BRAKE LIGHT SWITCH ................................3-36

CHECKING THE BRAKE HOSES ..........................................................3-37

BLEEDING THE HYDRAULIC BRAKE SYSTEM ...................................3-37

ADJUSTING THE SHIFT PEDAL ...........................................................3-39

CHECKING THE FINAL DRIVE OIL LEVEL ..........................................3-39

CHANGING THE FINAL DRIVE OIL ......................................................3-40

CHECKING AND ADJUSTING THE STEERING HEAD ........................3-41

CHECKING THE FRONT FORK ............................................................3-43

ADJUSTING THE FRONT FORK LEGS ................................................3-43

ADJUSTING THE REAR SHOCK ABSORBER ASSEMBLIES ..............3-44

CHECKING THE TIRES .........................................................................3-46

CHECKING THE WHEELS ....................................................................3-48

CHECKING AND LUBRICATING THE CABLES ....................................3-49

LUBRICATING THE LEVERS AND PEDALS ........................................3-49

LUBRICATING THE SIDESTAND ..........................................................3-50

LUBRICATING THE CENTERSTAND ...................................................3-50

LUBRICATING THE REAR SUSPENSION ............................................3-50

ELECTRICAL SYSTEM ................................................................................3-51

CHECKING THE BATTERY ...................................................................3-51

CHECKING THE FUSES ........................................................................3-55

REPLACING THE HEADLIGHT BULB ...................................................3-56

ADJUSTING THE HEADLIGHT BEAM ..................................................3-58

CHAPTER 4.

ENGINE

ENGINE REMOVAL ........................................................................................4-1

EXHAUST PIPES, MUFFLER AND AIR BAFFLE PLATES .....................4-1

BRAKE PEDAL, FOOTREST (RIGHT), MASTER CYLINDER

AND GROUND LEAD ..............................................................................4-2

LEADS, CABLES AND HOSES ................................................................4-3

ENGINE MOUNTING BOLTS ...................................................................4-4

INSTALLING THE ENGINE ......................................................................4-6

CAMSHAFTS ..................................................................................................4-7

CYLINDER HEAD COVERS ....................................................................4-7

CAMSHAFTS ............................................................................................4-9

REMOVING THE CAMSHAFTS .............................................................4-10

CHECKING THE CAMSHAFTS .............................................................4-11

CHECKING THE TIMING CHAIN, CAMSHAFT SPROCKETS,

AND TIMING CHAIN GUIDES ...............................................................4-13

CHECKING THE TIMING CHAIN TENSIONER .....................................4-13

INSTALLING THE CAMSHAFTS ...........................................................4-14

GEN

INFO 1

SPEC 2

CHK

ADJ 3

ENG 4

COOL 5

CARB 6

CHAS 7

ELEC 8

TRBL

SHTG 9

–

+

CYLINDER HEADS ......................................................................................4-21

REMOVING THE CYLINDER HEADS ...................................................4-22

CHECKING THE V-BOOST ...................................................................4-22

ADJUSTING THE BUTTERFLY SHAFT LEVER-TO-ADJUSTING

BOLT CLEARANCE ...............................................................................4-22

SYNCHRONIZING THE V-BOOST ........................................................4-24

CHECKING THE CYLINDER HEADS ....................................................4-25

INSTALLING THE CYLINDER HEAD ....................................................4-26

VALVES AND VALVE SPRINGS .................................................................4-27

REMOVING THE VALVES .....................................................................4-28

CHECKING THE VALVES AND VALVE GUIDES ..................................4-29

CHECKING THE VALVE SEATS ...........................................................4-31

CHECKING THE VALVE SPRINGS .......................................................4-33

CHECKING THE VALVE LIFTERS ........................................................4-34

INSTALLING THE VALVES ....................................................................4-34

CLUTCH ........................................................................................................4-36

CRANKCASE COVER (RIGHT SIDE) ....................................................4-36

CLUTCH ASSEMBLY .............................................................................4-37

REMOVING THE CLUTCH ....................................................................4-39

CHECKING THE FRICTION PLATES ....................................................4-39

CHECKING THE CLUTCH PLATES ......................................................4-40

CHECKING THE CLUTCH SPRING PLATE ..........................................4-40

CHECKING THE CLUTCH HOUSING ...................................................4-41

CHECKING THE CLUTCH BOSS ..........................................................4-41

CHECKING THE PRESSURE PLATE ...................................................4-41

CHECKING THE CLUTCH PUSH RODS ...............................................4-42

CHECKING THE PRIMARY DRIVE .......................................................4-42

INSTALLING THE CLUTCH ...................................................................4-42

SHIFT SHAFT ...............................................................................................4-45

GENERATOR ROTOR COVER .............................................................4-45

SHIFT SHAFT AND STOPPER LEVER .................................................4-46

CHECKING THE SHIFT SHAFT ............................................................4-47

CHECKING THE STOPPER LEVER ......................................................4-47

INSTALLING THE SHIFT SHAFT ..........................................................4-47

GENERATOR ...............................................................................................4-49

STATOR COIL ASSEMBLY ...................................................................4-49

GENERATOR .........................................................................................4-51

REMOVING THE GENERATOR ............................................................4-52

CHECKING THE STARTER CLUTCH ...................................................4-53

INSTALLING THE GENERATOR ...........................................................4-54

OIL PAN AND OIL PUMP .............................................................................4-55

OIL PUMP ...............................................................................................4-57

REMOVING THE OIL PAN .....................................................................4-59

CHECKING THE OIL PUMP ..................................................................4-59

CHECKING THE RELIEF VALVE ..........................................................4-60

CHECKING THE OIL DELIVERY PIPE ..................................................4-60

CHECKING THE OIL STRAINER ...........................................................4-60

ASSEMBLING THE OIL PUMP ..............................................................4-61

INSTALLING THE OIL STRAINER .........................................................4-62

INSTALLING THE OIL PAN ...................................................................4-62

CRANKCASE ...............................................................................................4-63

SEPARATING THE CRANKCASE .........................................................4-66

ASSEMBLING THE CRANKCASE .........................................................4-67

CRANKSHAFT .............................................................................................4-70

REMOVING THE CRANKSHAFT ASSEMBLY ......................................4-71

CHECKING THE CRANKSHAFT ...........................................................4-71

CHECKING THE BALANCER SHAFT ...................................................4-74

INSTALLING THE CRANKSHAFT .........................................................4-76

INSTALLING THE BALANCER SHAFT ..................................................4-77

CONNECTING RODS AND PISTONS .........................................................4-78

REMOVING THE CONNECTING RODS AND PISTONS ......................4-79

CHECKING THE CYLINDERS AND PISTONS ......................................4-80

CHECKING THE PISTON RINGS ..........................................................4-81

CHECKING THE PISTON PINS .............................................................4-82

INSTALLING THE PISTONS AND CYLINDERS ....................................4-85

TRANSMISSION ...........................................................................................4-88

CHECKING THE SHIFT FORKS ............................................................4-91

CHECKING THE SHIFT DRUM ASSEMBLY .........................................4-91

CHECKING THE TRANSMISSION ........................................................4-92

INSTALLING THE TRANSMISSION ......................................................4-93

MIDDLE GEAR .............................................................................................4-95

DISASSEMBLING THE MIDDLE DRIVE SHAFT ASSEMBLY ...............4-97

DISASSEMBLING THE MIDDLE DRIVEN SHAFT ASSEMBLY ............4-97

CHECKING THE MIDDLE DRIVE SHAFT ASSEMBLY .........................4-98

CHECKING THE MIDDLE DRIVEN SHAFT ASSEMBLY ......................4-99

ASSEMBLING THE MIDDLE DRIVE SHAFT ASSEMBLY .....................4-99

ASSEMBLING THE MIDDLE DRIVEN SHAFT ASSEMBLY ................4-100

INSTALLING THE MIDDLE GEAR .......................................................4-102

ADJUSTING THE MIDDLE GEAR BACKLASH ...................................4-103

ALIGNING THE MIDDLE GEAR ...........................................................4-106

GEN

INFO 1

SPEC 2

CHK

ADJ 3

ENG 4

COOL 5

CARB 6

CHAS 7

ELEC 8

TRBL

SHTG 9

–

+

CHAPTER 5.

COOLING SYSTEM

RADIATOR AND RADIATOR HOSES ...........................................................5-1

CHECKING THE RADIATOR ...................................................................5-3

INSTALLING THE RADIATOR .................................................................5-3

THERMOSTAT ASSEMBLY AND CONDUIT ................................................5-4

CHECKING THE THERMOSTAT .............................................................5-8

CHECKING THE RADIATOR CAP ...........................................................5-9

ASSEMBLING THE THERMOSTAT ASSEMBLY ....................................5-9

INSTALLING THE THERMOSTAT ASSEMBLY ....................................5-10

WATER PUMP ..............................................................................................5-11

DISASSEMBLING THE WATER PUMP .................................................5-14

CHECKING THE WATER PUMP ...........................................................5-14

ASSEMBLING THE WATER PUMP .......................................................5-16

INSTALLING THE WATER PUMP .........................................................5-17

CHAPTER 6.

CARBURETION

CARBURETORS ............................................................................................6-1

CHECKING THE CARBURETORS ..........................................................6-7

ASSEMBLING THE CARBURETORS ......................................................6-9

INSTALLING THE CARBURETORS ......................................................6-10

MEASURING AND ADJUSTING THE FUEL LEVEL ..............................6-11

CHECKING THE FUEL PUMP ...............................................................6-12

CHAPTER 7.

CHASSIS

FRONT WHEEL AND BRAKE DISCS ...........................................................7-1

REMOVING THE FRONT WHEEL ...........................................................7-4

DISASSEMBLING THE FRONT WHEEL .................................................7-4

CHECKING THE FRONT WHEEL ...........................................................7-5

CHECKING THE BRAKE DISCS .............................................................7-6

CHECKING THE SPEEDOMETER GEAR UNIT ......................................7-8

ASSEMBLING THE FRONT WHEEL .......................................................7-8

INSTALLING THE FRONT WHEEL .........................................................7-8

ADJUSTING THE FRONT WHEEL STATIC BALANCE ...........................7-9

REAR WHEEL AND BRAKE DISC ..............................................................7-12

REMOVING THE REAR WHEEL ...........................................................7-15

CHECKING THE REAR WHEEL ............................................................7-16

CHECKING THE REAR WHEEL DRIVE HUB .......................................7-16

INSTALLING THE REAR WHEEL ..........................................................7-16

ADJUSTING THE REAR WHEEL STATIC BALANCE ...........................7-17

FRONT AND REAR BRAKES ......................................................................7-18

REPLACING THE FRONT BRAKE PADS .............................................7-20

REPLACING THE REAR BRAKE PADS ................................................7-22

DISASSEMBLING THE FRONT BRAKE MASTER CYLINDER .............7-31

DISASSEMBLING THE REAR BRAKE MASTER CYLINDER ...............7-31

CHECKING THE FRONT AND REAR BRAKE

MASTER CYLINDERS ..........................................................................7-32

ASSEMBLING AND INSTALLING THE FRONT BRAKE

MASTER CYLINDER .............................................................................7-33

ASSEMBLING AND INSTALLING THE REAR BRAKE

MASTER CYLINDER .............................................................................7-35

DISASSEMBLING THE FRONT BRAKE CALIPERS .............................7-42

DISASSEMBLING THE REAR BRAKE CALIPER ..................................7-43

CHECKING THE FRONT AND REAR BRAKE CALIPERS ....................7-44

ASSEMBLING AND INSTALLING THE FRONT BRAKE CALIPERS ....7-45

ASSEMBLING AND INSTALLING THE REAR BRAKE CALIPER .........7-47

HYDRAULIC CLUTCH .................................................................................7-50

DISASSEMBLING THE CLUTCH MASTER CYLINDER ........................7-53

CHECKING THE CLUTCH MASTER CYLINDER ..................................7-54

ASSEMBLING AND INSTALLING THE CLUTCH

MASTER CYLINDER .............................................................................7-55

DISASSEMBLING THE CLUTCH RELEASE CYLINDER ......................7-61

CHECKING THE CLUTCH RELEASE CYLINDER ................................7-62

ASSEMBLING AND INSTALLING THE CLUTCH

RELEASE CYLINDER ...........................................................................7-63

FRONT FORK ...............................................................................................7-65

REMOVING THE FRONT FORK LEGS .................................................7-68

DISASSEMBLING THE FRONT FORK LEGS .......................................7-69

CHECKING THE FRONT FORK LEGS ..................................................7-70

ASSEMBLING THE FRONT FORK LEGS .............................................7-71

INSTALLING THE FRONT FORK LEGS ................................................7-74

HANDLEBAR ................................................................................................7-75

REMOVING THE HANDLEBAR .............................................................7-78

CHECKING THE HANDLEBAR ..............................................................7-78

INSTALLING THE HANDLEBAR ............................................................7-79

STEERING HEAD .........................................................................................7-81

REMOVING THE LOWER BRACKET ....................................................7-83

CHECKING THE STEERING HEAD ......................................................7-83

INSTALLING THE STEERING HEAD ....................................................7-84

GEN

INFO 1

SPEC 2

CHK

ADJ 3

ENG 4

COOL 5

CARB 6

CHAS 7

ELEC 8

TRBL

SHTG 9

–

+

REAR SHOCK ABSORBER .........................................................................7-86

HANDLING THE REAR SHOCK ABSORBER .......................................7-87

REMOVING THE REAR SHOCK ABSORBER ASSEMBLIES ...............7-87

CHECKING THE REAR SHOCK ABSORBER ASSEMBLIES ...............7-88

INSTALLING THE REAR SHOCK ABSORBER ASSEMBLIES .............7-88

SWINGARM ..................................................................................................7-89

REMOVING THE SWINGARM ...............................................................7-91

CHECKING THE SWINGARM ...............................................................7-92

INSTALLING THE SWINGARM .............................................................7-92

SHAFT DRIVE ..............................................................................................7-94

TROUBLESHOOTING ............................................................................7-94

CHECKING THE FINAL DRIVE OIL FOR CONTAMINATION

AND CHECKING THE SHAFT DRIVE FOR LEAKS .............................7-97

MEASURING THE RING GEAR BACKLASH ........................................7-98

ADJUSTING THE RING GEAR BACKLASH ..........................................7-99

MEASURING THE RING-GEAR-TO-STOPPER-BOLT

CLEARANCE .......................................................................................7-100

ADJUSTING THE RING-GEAR-TO-STOPPER-BOLT

CLEARANCE .......................................................................................7-100

DISASSEMBLING THE FINAL DRIVE ASSEMBLY .............................7-105

REMOVING AND INSTALLING THE RING GEAR BEARINGS ...........7-106

ALIGNING THE FINAL DRIVE PINION GEAR AND RING GEAR .......7-107

CHECKING THE DRIVE SHAFT ..........................................................7-113

INSTALLING THE FINAL DRIVE ASSEMBLY .....................................7-113

CHAPTER 8.

ELECTRICAL

ELECTRICAL COMPONENTS .......................................................................8-1

SWITCHES .....................................................................................................8-3

CHECKING SWITCH CONTINUITY .........................................................8-3

CHECKING THE SWITCHES .........................................................................8-4

CHECKING THE BULBS AND BULB SOCKETS .........................................8-6

TYPES OF BULBS ...................................................................................8-6

CHECKING THE CONDITION OF THE BULBS .......................................8-6

CHECKING THE CONDITION OF THE BULB SOCKETS .......................8-8

IGNITION SYSTEM .........................................................................................8-9

CIRCUIT DIAGRAM .................................................................................8-9

TROUBLESHOOTING ............................................................................8-10