Yamaha YW50AP User manual

YW50AP
5PJ-F8197-10LIT-11616-15-39

EB000000
YW50AP
SERVICE MANUAL
©2001 by Yamaha Motor Corporation U S A
First edition, November 2001
All rights reserved
Any reprinting or unauthorized use
without the written permission of
Yamaha Motor Corporation U S A
is expressly prohibited
P/N LIT-11616-15-39

EB001000
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.
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 scooter operator, a bystander or a person checking or repairing the
scooter.
A CAUTION indicates special precautions that must be taken to avoid dam
age to the scooter.
A NOTE provides key information to make procedures easier or clearer.
w
Q
NOTE:
cC

4
5
6
7
8
1
23
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 sec
tion 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 indi
cates 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.

EAS00009
SYMBOLS
The following symbols are not relevant to ev
ery vehicle.
Symbols 1 to 8 are designed as thumb tabs
to indicate the chapter’s number and content.
1General information
2Specifications
3Periodic inspection and adjustment
4Engine
5Carburetor(s)
6Chassis
7Electrical system
8Troubleshooting
Symbols 9 to y indicate the following.
9Serviceable with engine mounted
0Filling fluid
qLubricant
wSpecial tool
eTightening torque
rWear limit, clearance
tEngine speed
yElectrical data
Symbols u to s in the exploded diagrams in
dicate the types of lubricants and lubrication
points.
uEngine oil
iGear oil
oMolybdenum disulfide oil
pWheel bearing grease
aLithium soap base grease
sMolybdenum disulfide grease
Symbols d to f in the exploded diagrams
indicate the following.
dApply locking agent (LOCTITE ®)
fReplace the part
GEN
INFO
SPEC
INSP
ADJ
ENG
CARB
CHAS
–+
ELEC TRBL
SHTG
B
LS
M
LT
New
E
G
M
12
34
56
78
90
T
R
.
.
qw
er
t y
uio
pas
df

INDEX
GENERAL INFORMATION
SPECIFICATIONS
PERIODIC INSPECTION AND
ADJUSTMENT
ENGINE OVERHAUL
CARBURETION
CHASSIS
ELECTRICAL
TROUBLESHOOTING
1
2
3
4
5
6
7
8
–+

CHAPTER 1
GENERAL INFORMATION
SCOOTER INDENTIFICATION 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 2
BEARINGS AND OIL SEALS ......................................................................................................... 1 3
CIRCLIPS ........................................................................................................................................ 1 3
CHECKING OF CONNECTIONS 1 4
HOW TO USE THE CONVERSION TABLE 1 5
CONVERSION TABLE .................................................................................................................... 1 5
SPECIAL TOOLS 1 6

CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATION 2 1
MAINTENANCE SPECIFICATION 2 4
ENGINE .......................................................................................................................................... 2 4
TIGHTENING TORQUES ............................................................................................................... 2 6
ENGINE .......................................................................................................................................... 2 6
MAINTENANCE SPECIFICATION 2 7
CHASSIS ........................................................................................................................................ 2 7
TIGHTENING TORQUES ............................................................................................................... 2 8
CHASSIS ........................................................................................................................................ 2 8
MAINTENANCE SPECIFICATION 2 9
ELECTRICAL ................................................................................................................................... 2 9
GENERAL TORQUE SPECIFICATIONS 2 11
LUBRICATION POINTS AND LUBRICATION TYPE 2 12
ENGINE ........................................................................................................................................ 2 12
CHASSIS ...................................................................................................................................... 2 13
CABLE ROUTING 2 14

CHAPTER 3
PERIODIC INSPECTION AND ADJUSTMENTS
INTRODUCTION 3 1
PERIODIC MAINTENANCE/LUBRICATION INTERVALS 3 1
COVER AND PANEL 3 3
SIDECOVER AND SEAT ................................................................................................................ 3 3
LOWER COWLING, UPPER COVER, LEG SHIELD 1, 2 AND FOOTREST BOARD ..................... 3 4
HANDLEBAR COVER(FRONT AND REAR) ................................................................................... 3 5
ENGINE 3 6
IDLE SPEED ADJUSTMENT .......................................................................................................... 3 6
THROTTLE CABLE FREE ADJUSTMENT ..................................................................................... 3 7
AUTOLUBE PUMP AIR BLEEDING ............................................................................................... 3 8
SPARK PLUG INSPECTION...........................................................................................................39
ENGINE OIL LEVEL INSPECTION ............................................................................................... 3 10
TRANSMISSION OIL REPLACEMENT ........................................................................................ 3 11
AIR FILTER ELEMENT CLEANING .............................................................................................. 3 12
V BELT INSPECTION ................................................................................................................... 3 14
CHASSIS 3 15
FRONT BRAKE LEVER FREE PLAY CHECK ................................................................................ 3 15
REAR BRAKE LEVER FREE PLAY CHECK................................................................................... 3 15
BRAKE PAD INSPECTION ........................................................................................................... 3 15
BRAKE SHOE INSPECTION ........................................................................................................ 3 16
BRAKE FLUID LEVEL INSPECTION ............................................................................................ 3 16
AIR BLEEDING (HYDRAULIC BRAKE SYSTEM) ........................................................................ 3 17
STEERING ADJUSTMENT .......................................................................................................... 3 18
TIRE INSPECTION........................................................................................................................ 3 19
WHEEL INSPECTION ................................................................................................................... 3 22
FRONT FORK INSPECTION......................................................................................................... 3 22
REAR SHOCK ABSORBER INSPECTION.................................................................................... 3 22
SEAT LOCK CABLE ADJUSTMENT ........................................................................................... 3 22
CABLE CHECKING AND LUBRICATING..................................................................................... 3 23
LEVERS LUBRICATING ............................................................................................................... 3 23
CENTERSTAND LUBRICATING .................................................................................................. 3 23
ELECTRICAL 3 24
BATTERY INSPECTION ............................................................................................................... 3 24
FUSE INSPECTION ...................................................................................................................... 3 29
HEADLIGHT BEAM ADJUSTMENT ............................................................................................ 3 30
HEADLIGHT BULB REPLACEMENT............................................................................................ 3 30
TURN SIGNAL AND TAILLIGHT BULB REPLACEMENT ........................................................... 3 31
TAILLIGHT BULB REPLACEMENT .............................................................................................. 3 32
LICENSE LIGHT BULB REPLACEMENT...................................................................................... 3 32

CHAPTER 4
ENGINE
ENGINE OVERHAUL 4 1
WIREHARNESS AND CABLES ...................................................................................................... 4 1
CYLINDER HEAD, CYLINDER AND PISTON 4 3
CYLINDER HEAD, CYLINDER AND PISTON ................................................................................ 4 3
PISTON PIN AND PISTON REMOVAL .......................................................................................... 4 4
CYLINDER HEAD INSPECTION..................................................................................................... 4 4
CYLINDER AND PISTON INSPECTION ........................................................................................ 4 5
PISTON RINGS INSPECTION........................................................................................................ 4 7
PISTON PIN AND PISTON PIN BEARING .................................................................................... 4 7
PISTON PIN AND PISTON INSTALLATION ................................................................................. 4 8
CYLINDER AND CYLINDER HEAD ................................................................................................ 4 9
V-BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE 4 11
KICK STARTER AND CRANKCASE COVER(LEFT)..................................................................... 4 11
KICK STARTER............................................................................................................................. 4 12
KICK STARTER INSTALLATION ................................................................................................. 4 13
V BELT, CLUTCH AND SECONDARY/PRIMARY SHEAVE ........................................................ 4 14
SECONDARY SHEAVE ................................................................................................................ 4 15
PRIMARY SHEAVE REMOVAL.................................................................................................... 4 16
SECONDARY SHEAVE REMOVAL.............................................................................................. 4 16
CLUTCH INSPECTION ................................................................................................................. 4 17
V BELT INSPECTION ................................................................................................................... 4 18
PRIMARY SHEAVE INSPECTION................................................................................................ 4 19
SECONDARY SHEAVE ................................................................................................................ 4 20
SECONDARY SHEAVE INSTALLATION ..................................................................................... 4 21
PRIMARY SHEAVE ...................................................................................................................... 4 22
STARTER CLUTCH AND STARTER MOTOR 4 24
STARTER CLUTCH AND STARTER MOTOR.............................................................................. 4 24
STARTER CLUTCH AND GEARS INSPECTION ......................................................................... 4 26
C D I MAGNET 4 27
C.D.I. MAGNETO ......................................................................................................................... 4 27
C.D.I. MAGNETO REMOVAL....................................................................................................... 4 28
C.D.I. MAGNETO INSTALLATION .............................................................................................. 4 28
AUTOLUBE PUMP 4 29
AUTOLUBE PUMP ....................................................................................................................... 4 29
AUTOLUBE PUMP INSTALLATION ........................................................................................... 4 30
TRANSMISSION 4 31
TRANSMISSION .......................................................................................................................... 4 31
CRANKCASE AND REED VALVE 4 33
CRANKCASE AND REED VALVE ................................................................................................ 4 33
CRANKCASE(RIGHT) REMOVAL ................................................................................................ 4 35
CHECKING THE CRANKCASE .................................................................................................... 4 35
CHECKING THE BEARINGS AND OIL SEALS ............................................................................ 4 35
REED VALVE INSPECTION ......................................................................................................... 4 36
CRANKCASE (RIGHT) INSTALLATION ...................................................................................... 4 36
CRANKSHAFT 4 38
CRANKSHAFT .............................................................................................................................. 4 38
CRANKSHAFT REMOVAL ........................................................................................................... 4 39
CRANKSHAFT INSPECTION ....................................................................................................... 4 39
CRANKSHAFT INSTALLATION................................................................................................... 4 40