Yamaha 5KM2-AE1 User manual

YFM660F(P)
5KM2-AE1
SERVICEMANUAL
2002

YFM660F(P) 2002
SERVICE MANUAL
© 2001 by Yamaha Motor Co., Ltd.
First edition, May 2001
All rights reserved.
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.

EB001000
NOTICE
This manual was produced by the Yamaha Motor Company primarily for use by Yamaha dealers
and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one
manual, so it is assumed that anyone who uses this book to perform maintenance and repairs on
Yamaha machine has a basic understanding of the mechanical ideas and the procedures of
machine repair. Repairs attempted by anyone without this knowledge are likely to render the
machine unsafe and unfit for use.
Yamaha Motor Company, Ltd. is continually striving to improve all its models. Modifications and sig-
nificant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers
and will appear in future editions of this manual where applicable.
N
OTE:
Designs and specifications are subject to change without notice.
IMPORTANT INFORMATION
Particularly important information is distinguished in this manual by the following notations.
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR
SAFETY IS INVOLVED!
Failure to follow WARNING instructions could result in severe injury or death
to the machine operator, a bystander or a person inspecting or repairing the
machine.
A CAUTION indicates special precautions that must be taken to avoid dam-
age to the machine.
A NOTE provides key information to make procedures easier or clearer.
WARNING
CAUTION:
NOTE:

EB002000
HOW TO USE THIS MANUAL
MANUAL ORGANIZATION
This manual consists of chapters for the main categories of subjects. (See “Illustrated symbols”)
1st title 1: This is the title of the chapter with its symbol in the upper right corner of each page.
2nd title 2: This title indicates the section of the chapter and only appears on the first page of each
section. It is located in the upper left corner of the page.
3rd title 3: This title indicates a sub-section that is followed by step-by-step procedures accompa-
nied by corresponding illustrations.
EXPLODED DIAGRAMS
To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each
removal and disassembly section.
1. An easy-to-see exploded diagram 4is provided for removal and disassembly jobs.
2. Numbers 5are 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 7accompanies 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 8are given in addition
to the exploded diagram and the job instruction chart.

EB003000
ILLUSTRATED SYMBOLS
Illustrated symbols 1to 0are printed on the
top right of each page and indicate the subject
of each chapter.
1General information
2Specifications
3Periodic checks and adjustments
4Engine
5Cooling system
6Carburetion
7Drive train
8Chassis
9Electrical
0Troubleshooting
Illustrated symbols Ato Hare used to identify
the specifications appearing in the text.
ACan be serviced with engine mounted
BFilling fluid
CLubricant
DSpecial tool
ETorque
FWear limit, clearance
GEngine speed
HΩ, V, A
Illustrated symbols Ito Nin the exploded
diagrams indicate the types of lubricants and
lubrication points.
IApply engine oil
JApply gear oil
KApply molybdenum disulfide oil
LApply wheel bearing grease
MApply lightweight lithium-soap base grease
NApply molybdenum disulfide grease
Illustrated symbols Oto Pin the exploded
diagrams indicate where to apply a locking
agent Oand when to install a new part P.
OApply the locking agent (LOCTITE)
PReplace
12
34
56
78
90
AB
CD
EF
GH
IJK
LMN
OP
GEN
INFO SPEC
CHK
ADJ ENG
COOL CARB
DRIV
CHAS
–+
ELEC TRBL
SHTG
T
R
.
.
EGM
BLS M
LT New

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
DRIVE TRAIN DRIV 7
CHASSIS CHAS 8
ELECTRICAL ELEC 9
TROUBLESHOOTING TRBL
SHTG
10
–+

GEN
INFO 1

GEN
INFO
CHAPTER 1.
GENERAL INFORMATION
MACHINE IDENTIFICATION ........................................................................ 1-1
VEHICLE IDENTIFICATION NUMBER ................................................. 1-1
MODEL LABEL ..................................................................................... 1-1
FEATURES ................................................................................................... 1-2
FRONT DIFFERENTIAL ....................................................................... 1-2
TRANSMISSION ................................................................................... 1-9
IMPORTANT INFORMATION .................................................................... 1-10
PREPARATION FOR REMOVAL PROCEDURES ............................. 1-10
REPLACEMENT PARTS .................................................................... 1-10
GASKETS, OIL SEALS AND O-RINGS .............................................. 1-10
LOCK WASHERS/PLATES AND COTTER PINS ............................... 1-11
BEARINGS AND OIL SEALS .............................................................. 1-11
CIRCLIPS ............................................................................................ 1-11
CHECKING OF CONNECTIONS ............................................................... 1-12
SPECIAL TOOLS ....................................................................................... 1-13

GEN
INFO

1 - 1
GEN
INFO
MACHINE IDENTIFICATION
GENERAL INFORMATION
MACHINE IDENTIFICATION
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number 1is
stamped into the left side of the frame.
MODEL LABEL
The model label 1is affixed to the frame. This
information will be needed to order spare
parts.

GEN
INFO
1 - 2
FEATURES
FRONT DIFFERENTIAL
1Adapter
2Drive clutch
3Differential side gear (left)
4Differential pinion gear
5Ring gear
6Differential side gear (right)
7Drive pinion gear
8Gear motor
ÈTo front wheel
ÉFrom the middle gear
FEATURES

GEN
INFO
1 - 3
FEATURES
2WD
Power is transmitted as follows: middle gear →front drive shaft →drive pinion gear 7→ring gear
5→differential pinion gear 4. In the 2WD mode, the left differential side gear 3and the drive
clutch 2are not engaged, therefore, the left side gear runs idle and does not transmit power to the
left front constant velocity joint.

GEN
INFO
1 - 4
FEATURES
4WD
When the 4WD mode is selected, the gear motor is operated, and the drive clutch 2moves to the
right and engages with the left differential side gear 3. Accordingly, power is transmitted as follows:
ring gear 5→differential pinion gear 4→left differential side gear 3→drive clutch 2→adapter
1→left front constant velocity joint.
Meanwhile, power from the differential pinion gear 4is transmitted to the right front constant veloc-
ity joint via the right differential side gear 6.
The ring gear 5and the drive clutch 2are not engaged at this time. Therefore, the rotational differ-
ence that occurs between the right and left wheels, while the handlebar is being turned, is absorbed
by the difference in the rotational speeds of the ring gear 5and the left differential side gear 3.

GEN
INFO
1 - 5
FEATURES
4WD (Diff-Lock)
When the 4WD (Diff-Lock) mode is selected, the gear motor moves the drive clutch 2further to the
right, which causes the ring gear 5and the drive clutch 2to engage. As a result, power is transmit-
ted directly from the ring gear 5to the drive clutch 2, then to the left front constant velocity joint via
the adapter 1.
Meanwhile, because the ring gear 5and the drive clutch 2are engaged, the ring gear 5, the drive
clutch 2, and the right differential side gear 6become locked coaxially. Thus, power is transmitted
as follows: differential pinion gear 4→right differential pinion gear 6→right front constant veloc-
ity joint.
When the ATV is in the 4WD (Diff-Lock) mode, the right and left wheels rotate constantly at the
same speed, which affects the maneuverability of the ATV (e.g., making it difficult to steer). There-
fore, the maximum traveling speed is limited to 35 km/h (22 mph).

GEN
INFO
1 - 6
FEATURES
In addition, the 4WD (Diff-Lock) mode can be engaged only when the ATV is stopped. Even if an
attempt is made to select this mode when the ATV is traveling, it will only result in a standby condi-
tion (i.e., when the differential lock select switch and the differential gear are not matched).
(1) When the ATV is traveling
Even if the 4WD (Diff-Lock) mode is selected, the gear motor will stand by, instead of operating.
Therefore, the ATV can be driven in the normal 4WD mode. When this occurs, the differential gear
lock indicator light “”in the speedometer unit will flash to alert the driver that the control is on
standby. When the ATV is stopped, the control transfers to the condition described in (2).
(2) When the ATV is stopped
The gear motor operates to connect the drive clutch to the differential case, thus resulting in the
differential lock condition. When this occurs, the differential gear lock indicator light “”in the
speedometer unit changes to a constant illumination.
* Until the drive clutch and the differential case mesh together (i.e., the splines are unmeshed) the
engine misfires to control the engine speed. During this time, the differential gear lock indicator light
in the speedometer unit continues to flash.
DIFF.
LOCK
DIFF.
LOCK

GEN
INFO
1 - 7
FEATURES
Shift mechanism
A new shift mechanism with a parking position has been added to the YFM660F.
1.Shift cam
2.Shift fork guide bar
3.Drive axle
4.Stopper lever shaft
L
L
HNR
P
HNR
P
1
2
3
4
1
2
3
4

GEN
INFO
1 - 8
FEATURES
Parking
(1) L (Low), H (High), N (Neutral), and R (Reverse) positions
The end of the stopper lever is held by the return spring 1. Then, the stopper lever tab is sepa-
rated from the drive axle stopper to free the drive axle.
(2) P (Park) position
When the drive select lever is shifted to the “P”position, the cam lever of the shift cam pushes
up on the end of the stopper lever. Then, the stopper lever tab pushes against the drive axle
stopper to lock the drive axle.
(3) Not synchronized
If the stopper lever tab and the drive axle stopper are not synchronized, the torsion spring is
compressed. As a result, the spring pushes the stopper lever tab against the drive axle stopper
and waits until the synchronization is completed. When the stop lever tab and the drive axle are
synchronized, the stop lever tab pushes against the drive axle stopper in order to lock the drive
axle.
1 Stopper lever
2 Return spring
3 Shift cam
4 Drive axle
4
1
2
3
4
1
2
3
4
1
2
3
(1) (2) (3)

GEN
INFO
1 - 9
FEATURES
TRANSMISSION
To create a compact, 3-axle transmission, a chain drive has been adopted for the reverse transmis-
sion.
1Secondary shaft
2Drive axle
3Middle drive shaft
4Low wheel gear
5Chain
1Secondary shaft
2Drive axle
L (Low) or H (High) mode
When the transmission is in either the low or
high mode, the drive axle is driven via the sec-
ondary shaft and gear. Therefore, the rotation
of the drive axle is the opposite of the second-
ary shaft.
R (Reverse) mode
When the transmission is in the reverse mode,
the drive axle is driven via the drive chain.
Therefore, the rotation of the drive axle is the
same as the secondary shaft. (As a result, the
rotation of the drive axle is opposite to that of
the low and high modes.)