Yamaha VMX12 2001 User manual

VMX12 2001
3LRD-AE1
SERVICE MANUAL

EAS00000
VMX12 2001
SERVICE MANUAL
© 2000 by Yamaha Motor Co., Ltd.
First edition, June 2000
All rights reserved.
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.

EAS00002 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.
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:
@
Designs and specifications are subject to change without notice.
@
EAS00004
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:

EAS00007 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.
1The manual is divided into chapters. An abbreviation and symbol in the upper right corner of
each page indicate the current chapter.
Refer to “SYMBOLS”.
2Each 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.
3Sub-section titles appear in smaller print than the section title.
4To help identify parts and clarify procedure steps, there are exploded diagrams at the start of
each removal and disassembly section.
5Numbers are given in the order of the jobs in the exploded diagram. A circled number indicates a
disassembly step.
6Symbols indicate parts to be lubricated or replaced.
Refer to “SYMBOLS”.
7A job instruction chart accompanies the exploded diagram, providing the order of jobs, names of
parts, notes in jobs, etc.
8Jobs requiring more information (such as special tools and technical data) are described sequen-
tially.

EAS00008
SYMBOLS
The following symbols are not relevant to
every vehicle.
Symbols 1to 9indicate the subject of each
chapter.
1General information
2Specifications
3Periodic checks and adjustments
4Engine
5Cooling system
6Carburetion
7Chassis
8Electrical system
9Troubleshooting
Symbols 0to Gindicate the following.
0Serviceable with engine mounted
AFilling fluid
BLubricant
CSpecial tool
DTightening torque
EWear limit, clearance
FEngine speed
GElectrical data
Symbols Hto Min the exploded diagrams
indicate the types of lubricants and lubrication
points.
HEngine oil
IGear oil
JMolybdenum disulfide oil
KWheel bearing grease
LLithium soap base grease
MMolybdenum disulfide grease
Symbols Nto Oin the exploded diagrams
indicate the following.
NApply locking agent (LOCTITE®)
OReplace the part
12
34
56
78
90
AB
CD
EFG
HIJ
KLM
NO
GEN
INFO
SPEC
CHK
ADJ ENG
COOL CARB
CHAS
–+
ELEC
TRBL
SHTG
T
R
.
.
EGM
BLS M
LT New

EAS00012 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
–+

GEN
INFO
1

GEN
INFO
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

GEN
INFO

1 - 1
GEN
INFO
EAS00014
GENERAL INFORMATION
MOTORCYCLE IDENTIFICATION
EAS00017
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number 1is
stamped into the right side of the steering head
pipe.
EAS00018
MODEL CODE
The model code label 1is affixed to the
frame. This information will be needed to order
spare parts.
MOTORCYCLE IDENTIFICATION

1 - 2
GEN
INFO
IMPORTANT INFORMATION
EAS00020
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 the “SPECIAL TOOLS”.
3. When disassembling, always keep mated
parts together. This includes gears, cylin-
ders, 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 dis-
assembly. This will speed up assembly and
allow for the correct installation of all parts.
5. Keep all parts away from any source of fire.
EAS00021
REPLACEMENT PARTS
Use only genuine Yamaha parts for all
replacements. Use oil and grease recom-
mended by Yamaha for all lubrication jobs.
Other brands may be similar in function and
appearance, but inferior in quality.
EAS00022
GASKETS, OIL SEALS AND O-RINGS
1. When overhauling the engine, replace all
gaskets, seals and O-rings. All gasket sur-
faces, 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 - 3
GEN
INFO
EAS00023
LOCK WASHERS/PLATES AND COTTER
PINS
After removal, replace all lock washers/plates
1and cotter pins. After the bolt or nut has
been tightened to specification, bend the lock
tabs along a flat of the bolt or nut.
EAS00024
BEARINGS AND OIL SEALS
Install bearings and oil seals so that the manu-
facturer’s marks or numbers are visible. When
installing oil seals, lubricate the oil seal lips
with a light coat of lithium soap base grease.
Oil bearings liberally when installing, if appro-
priate.
1Oil seal
CAUTION:
@
Do not spin the bearing with compressed
air because this will damage the bearing
surfaces.
@
1Bearing
EAS00025
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 2is positioned opposite
the thrust 3that the circlip receives.
4Shaft
IMPORTANT INFORMATION

1 - 4
GEN
INFO
IMPORTANT INFORMATION
EAS00026
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 sev-
eral times.
3. Check:
• all connections
Loose connection →Connect properly.
NOTE:
@
If the pin 1on 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)
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.
@
Pocket tester
90890-03112

1 - 5
GEN
INFO
SPECIAL TOOLS
EAS00027
SPECIAL TOOLS
The following special tools are necessary for complete and accurate tune-up and assembly. Use
only the appropriate special tools as this will help prevent damage caused by the use of inappropri-
ate tools or improvised techniques. Special tools, part numbers or both may differ depending on the
country.
When placing an order, refer to the list provided below to avoid any mistakes.
Tool No. Tool name/Function Illustration
90890-01122
Valve guide remover (5.5 mm)
This tool is needed to remove and
install the valve guide.
90890-01196
Valve guide reamer (5.5 mm)
This tool is needed to rebore the new
valve guide.
90890-01229
Coupling gear/middle shaft tool
This tool is needed when removing or
installing the coupling gear nut.
90890-01230
Final gear backlash band
This tool is needed when measuring
final gear backlash.
90890-01304
Piston pin puller set
This tool is used to remove the piston
pin.
90890-01312
Fuel level gauge
This gauge is used to measure the fuel
level in the float chamber.
Tester
90890-01325
Adapter
90890-01352
Radiator cap tester
Adapter
This tester and its adapter are needed
for checking the cooling system.

1 - 6
GEN
INFO
SPECIAL TOOLS
Puller
90890-01362
Attachment
90890-04089
Flywheel puller
Attachment
These tools are needed to remove the
rotor.
Weight
90890-01367
Attachment
90890-01373
Fork seal driver weight
Attachment (f40)
These tools are needed when installing
the slide metal, oil seal and dust seal
into the fork.
Rod holder
90890-01375
T-handle
90890-01326
Damper rod holder (29 mm)
T-handle
These tools are needed to loosen and
tighten the damper rod holding bolt.
90890-01403
Steering nut wrench
This tool is needed to loosen and
tighten the steering stem ring nut.
90890-01426
Oil filter wrench
This tool is needed to remove and
install the oil filter.
90890-01701
Sheave holder
This tool is needed to hold the rotor
when removing or installing the rotor
bolt.
90890-03017
Cylinder bore gauge (50 ~ 100 mm)
This tool is used to measure the cylin-
der bore.
90890-03081
Compression gauge
These tools are needed to measure
engine compression.
Tool No. Tool name/Function Illustration

1 - 7
GEN
INFO
SPECIAL TOOLS
90890-03094
Vacuum gauge
This gauge is needed for carburetor
synchronization.
90890-03097
Dial gauge
This tool is used to measure the middle
gear backlash.
90890-03112
Pocket tester
This instrument is needed for checking
the electrical system.
90890-03113
Engine tachometer
This tool is needed for observing engine
rpm.
90890-03141
Timing light
This tool is necessary for checking igni-
tion timing.
Gauge
90890-03153
Oil pressure adaptor B
90890-03124
Pressure gauge
Oil pressure adaptor B
These tools are needed to measure
engine oil pressure.
90890-04015
Valve guide installer (5.5 mm)
This tool is needed to install the valve
guide.
Compressor
90890-04019
Attachment
90890-04114
Valve spring compressor/attachment
These tools are needed to remove and
install the valve assemblies.
Tool No. Tool name/Function Illustration

1 - 8
GEN
INFO
SPECIAL TOOLS
90890-04050
Bearing retainer wrench
This tool is needed when removing or
installing the final drive shaft bearing.
90890-04054
Middle drive shaft nut wrench (55 mm)
This tool is needed when removing or
installing the middle drive shaft nut.
YM-33222
Middle drive gear holder
This tool is needed to remove and
install the middle drive pinion gear.
This tool is also used for the gear back-
lash adjustment.
90890-04062
Universal joint holder
This tool is needed when removing or
installing the driven pinion gear nut.
90890-04080
Middle gear backlash tool
This tool is needed for the gear back-
lash adjustment.
90890-04086
Clutch holding tool
This tool is needed to hold the clutch
when removing or installing the clutch
boss nut.
90890-04090
Damper spring compressor
This tool is needed when removing or
installing the damper spring.
90890-04105
Tappet adjusting tool
This tool is needed to rotate the cam-
shaft for access to the valve lifter and
valve pad.
Tool No. Tool name/Function Illustration