SERVICE MANUAL
LIT-11616-18-38
5RU-28197-10
EAS00001
YP400T
SERVICE MANUAL
©2004 by Yamaha Motor Corporation, U.S.A.
First edition, June 2004
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-11616-18-38
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 scooter operator, a bystander or a person checking or repairing the scooter.
A CAUTION indicates special precautions that must be taken to avoid damage
to the scooter.
A NOTE provides key information to make procedures easier or clearer.
CAUTION:
NOTE:
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WARNING
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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.
1
2
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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
GEN
INFO
SPEC
3
4
CHK
ADJ
General information
CHAS
2
Specifications
3
Periodic checks and adjustments
4
Chassis
5
6
5
Engine
6
Cooling system
ENG
COOL
7
Fuel injection system
8
Electrical system
9
Troubleshooting
7
8
FI
ELEC
–
+
9
0
Symbols
0
to
G
indicate the following.
0
Serviceable with engine mounted
TRBL
SHTG
A
Filling fluid
B
Lubricant
C
Special tool
D
Tightening torque
A
B
E
Wear limit, clearance
F
Engine speed
G
Electrical data
C
D
E
F
G
H
I
J
Symbols
H
to
M
in the exploded diagrams
indicate the types of lubricants and lubrication
points.
H
E
G
M
Engine oil
Gear oil
I
K
L
M
J
Molybdenum-disulfide oil
K
Wheel-bearing grease
B
LS
M
L
Lithium-soap-based grease
M
Molybdenum-disulfide grease
N
O
Symbols
N
to
O
in the exploded diagrams
indicate the following.
N
New
Apply locking agent (LOCTITE
®
)
LT
O
Replace the part