Yamaha XP500 User manual

2005
XP500
XP500A
5VU5-AE1
SERVICE MANUAL

EAS00000
XP500/XP500A 2005
SERVICE MANUAL
©2004 by Yamaha Motor Co., Ltd.
First edition, September 2004
All rights reserved.
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.

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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.
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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.
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.
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.
612
4
7
5
3
8

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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
4Chassis
5Engine
6Cooling system
7Fuel injection system
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- based 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
CHAS
ENG
COOL
FI –+
ELEC
TRBL
SHTG
T
R
.
.
EGM
BLS 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
CHASSIS CHAS 4
ENGINE ENG 5
COOLING SYSTEM COOL 6
FUEL INJECTION SYSTEM FI 7
ELECTRICAL SYSTEM ELEC 8
TROUBLESHOOTING TRBL
SHTG 9
–+

GEN
INFO 1

GEN
INFO
CHAPTER 1
GENERAL INFORMATION
SCOOTER IDENTIFICATION..........................................................................1-1
VEHICLE IDENTIFICATION NUMBER .....................................................1-1
MODEL LABEL..........................................................................................1-1
FEATURES......................................................................................................1-2
OUTLINE OF FI SYSTEM .........................................................................1-2
FI SYSTEM................................................................................................1-3
OUTLINE OF ANTI-LOCK BRAKE SYSTEM (XP500A) ...........................1-4
INSTRUMENT FUNCTION .....................................................................1-15
IMPORTANT INFORMATION .......................................................................1-19
PREPARATION FOR REMOVAL AND DISASSEMBLY.........................1-19
REPLACEMENT PARTS.........................................................................1-19
GASKETS, OIL SEALS AND O-RINGS ..................................................1-19
LOCK WASHERS/PLATES AND COTTER PINS ...................................1-20
BEARINGS AND OIL SEALS ..................................................................1-20
CIRCLIPS ................................................................................................1-20
CHECKING THE CONNECTIONS ................................................................1-21
SPECIAL TOOLS ..........................................................................................1-22

GEN
INFO

1 - 1
GEN
INFO
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GENERAL INFORMATION
SCOOTER IDENTIFICATION
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VEHICLE IDENTIFICATION NUMBER
The vehicle identification number 1is
stamped into the right side of the frame.
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MODEL LABEL
The model label 2is affixed to the storage
box. This information will be needed to order
spare parts.
SCOOTER IDENTIFICATION

1 - 2
GEN
INFO
FEATURES
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FEATURES
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OUTLINE OF FI SYSTEM
The main function of a fuel supply system is to provide fuel to the combustion chamber at the opti-
mum air-fuel ratio in accordance with the engine operating conditions. In a conventional carburetor
system, the air-fuel ratio of the mixture that is supplied to the combustion chamber is created by the
volume of the intake air and the fuel that is metered by the jet used in the respective chamber.
Despite the same volume of intake air, the fuel volume requirement varies with the engine operating
conditions, such as acceleration, deceleration, or operation under a heavy load. Carburetors that
meter the fuel through the use of jets have been provided with various auxiliary devices, so that an
optimum air-fuel ratio can be achieved to accommodate the constant changes in the operating con-
ditions of the engine.
As the requirements for engines to deliver more performance and cleaner exhaust gases increase,
it becomes necessary to control the air-fuel ratio in a more precise and finely tuned manner. To
accommodate this need, this model has adopted an electronically controlled fuel injection (FI) sys-
tem in place of a conventional carburetor system. This system can achieve an optimum air-fuel ratio
required by the engine at all times by using a microprocessor that regulates the fuel injection volume
according to the engine operating conditions detected by various sensors.
Adoption of the FI system has resulted in a highly precise fuel supply, improved engine response,
better fuel economy, and reduced exhaust emissions.
1Ignition coil
2Air filter case
3Intake air temperature sensor
4Fuel injection system relay
5Lean angle cut-off switch
6Engine trouble warning light
7ECU (engine)
8Intake air pressure sensor
9Throttle position sensor
0Fuel injector
AFuel tank
BFuel delivery hose
CFuel pump
DBattery
ECatalyst
FO2sensor
GCrankshaft position sensor
HCoolant temperature sensor
ISpark plug
1
2
3
4567
89
0
ABC
D
FE
G
H
I

1 - 3
GEN
INFO
FEATURES
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FI SYSTEM
The fuel pump delivers fuel to the fuel injector via the fuel filter. The pressure regulator (in the fuel
pump) maintains the fuel pressure that is applied to the fuel injector at 240 ~ 260 kPa (2.40 ~
2.60 kg/cm2, 34.1 ~ 37.0 psi) higher than the intake manifold pressure. Accordingly, when the ener-
gizing signal from the ECU (engine) energizes the fuel injector, the fuel passage opens, causing the
fuel to be injected into the intake manifold only during the time the passage remains open. There-
fore, the longer the length of time the fuel injector is energized (injection duration), the greater the
volume of fuel that is supplied. Conversely, the shorter the length of time the fuel injector is ener-
gized (injection duration), the lesser the volume of fuel that is supplied.
The injection duration and the injection timing are controlled by the ECU (engine). Signals that are
input from the throttle position sensor, crankshaft position sensor, intake air pressure sensor, intake
air temperature sensor, coolant temperature sensor, and O2sensor enable the ECU (engine) to
determine the injection duration. The injection timing is determined through the signals from the
crankshaft position sensor. As a result, the volume of fuel that is required by the engine can be sup-
plied at all times in accordance with the driving conditions.
1Fuel pump
2Fuel injector
3Ignition coil
4ECU (engine)
5Catalyst
6O2sensor
7Coolant temperature sensor
8Crankshaft position sensor
9Intake air pressure sensor
0Throttle body
AIntake air temperature sensor
BAir filter case
CThrottle position sensor
ÈFuel system
ÉAir system
ÊControl system
2
3
4
6
7
8
9
0
A
B
1
5
È
É
ÊC
Illustration is for reference only.

1 - 4
GEN
INFO
FEATURES
OUTLINE OF ANTI-LOCK BRAKE SYSTEM (XP500A)
Yamaha ABS features
1. The Yamaha ABS (Anti-Lock Brake System) features a dual electronic control system, which acts
on the front and rear brakes independently.
2. The ABS features a compact and lightweight design to help maintain the basic maneuverability of
the vehicle.
3. The hydraulic unit, which is the main component of the ABS, is centrally located on the vehicle to
increase mass centralization.
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The operation of the Yamaha ABS brakes is the same as conventional vehicle, with a right hand
brake lever for operating the front wheel brake and a left hand brake lever for operating the rear
wheel brake.
When wheel lockup is detected during emergency braking, hydraulic control is performed by the
hydraulic system independently.
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The ABS also includes a highly developed self-diagnostic function. The ABS detects any problem
conditions and allows normal braking even if the ABS is not operating properly.
When this occurs, the ABS warning light on the meter assembly comes on.
The ABS stores the malfunction codes in the memory of the ECU (ABS) for easy problem identifica-
tion and troubleshooting.
ABS layout
1ABS warning light
2Fail-safe relay
3Electronic control unit (ECU)
4Hydraulic unit
5Rear disc rotor
6Rear brake caliper
7Rear wheel sensor
8Front brake caliper
9Front wheel sensor
0Front disc rotor
1
2
3
4
0
987
6
5

1 - 5
GEN
INFO
FEATURES
ABS block diagram
1Rear brake master cylinder
2Hydraulic unit
3Hydraulic pump
4ABS motor
5Buffer chamber
6Hydraulic control valve
7Front brake master cylinder
8Rear brake caliper
9Front brake caliper
0ECU (ABS)
ARear wheel sensor
BFront wheel sensor
CABS warning light

1 - 6
GEN
INFO
FEATURES
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Useful terms
•Wheel speed:
The rotation speed of the front and rear
wheels.
•Chassis speed:
The speed of the chassis.
When the brakes are applied, wheel speed
and chassis speed are reduced. However,
the chassis travels forward by its inertia
even though the wheel speed is reduced.
•Brake force:
The force applied by braking to reduce the
wheel speed.
•Wheel lock:
A condition that occurs when the rotation of
one or both of the wheels has stopped but
the vehicle continues to travel.
•Side force:
The force on the tires which supports the
vehicle when cornering.
•Slip ratio:
When the brakes are applied, slipping
occurs between the tires and the road sur-
face. This causes a difference between the
wheel speed and the chassis speed.
Slip ratio is the value that shows the rate of
wheel slippage and is defined by the follow-
ing formula.
Slip ratio = ×100 (%)
0%:
There is no slip between the wheel and the
road surface. The chassis speed is equal to
the wheel speed.
100%:
The wheel speed is “0”, but the chassis is
moving (i.e., wheel lock).
Chassis speed –Wheel speed
Chassis speed

1 - 7
GEN
INFO
FEATURES
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Brake force and vehicle stability
When the brake pressure is increased, wheel
speed is reduced. Slip occurs between the tire
and the road surface and brake force is gener-
ated. The limit of this brake force is determined
by the friction force between the tire and the
road surface and is closely related to wheel
slippage. Wheel slippage is represented by the
slip ratio.
Therefore, side force is also closely related to
wheel slippage. See figure È. If the brakes are
applied while keeping the proper slip ratio, it is
possible to obtain the maximum brake force
without losing much side force.
ABS allows full use of the tire capabilities even
on slippery road surfaces or less slippery road
surfaces. See figure É.
ÈBrake force
Side force
Slip ratio (%)
Friction force between the tire and road surface
É
Friction force between the tire and road surface
Less slippery
road surface
Controlling zone
Slippery road surface
Slip ratio (%)
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Wheel slip and hydraulic control
The ECU (ABS) calculates the wheel speed of
each wheel according to the rotation signal
received from the front and rear wheel sen-
sors. In addition, the ECU (ABS) calculates the
vehicle chassis speed and the rate of speed
reduction based on the wheel speed values.
The difference between the chassis speed and
the wheel speed calculated in the slip ratio for-
mula is equal to the wheel slip. When the
wheel has a tendency to lock, the wheel speed
is suddenly reduced. When the wheel slip and
the wheel speed reduction rate exceed the
preset values, the ECU (ABS) determines that
the wheel has a tendency to lock.
If the slip is large and the wheel has a ten-
dency to lock (point A in the figure), the ECU
(ABS) reduces the brake fluid pressure in the
brake caliper and increases the pressure of
the brake fluid in the brake caliper when the
tendency to lock has diminished (point B in the
figure).
Vehicle speed
Wheel speed
Pressurized
Depressurized
Brake force

1 - 8
GEN
INFO
FEATURES
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ABS operation and vehicle control
If the ABS starts operating, there is a tendency
of the wheel to lock, and the vehicle is
approaching the limit of control. To make the
rider aware of this condition, the ABS has been
designed to generate a reaction-force pulsat-
ing action in the brake lever.
NOTE:
_
When the ABS is activated, a pulsating action
may be felt at the brake lever, but this does not
indicate a malfunction.
The higher the cornering force on a tire, the
less traction there is available for braking. This
is true whether the vehicle is equipped with an
ABS or not. Therefore, sudden braking while
cornering is not recommended. Excessive cor-
nering force, which an ABS cannot prevent,
could cause the tire to slip sideways.
WARNING
_
The braking of the vehicle, even in the
worst case, is principally executed when
the vehicle is advancing straight ahead.
During a turn, sudden braking is liable to
cause a loss of traction of the tires. Even in
vehicles equipped with an ABS, overturn-
ing of the vehicle cannot be prevented if it
is braked suddenly.
The ABS functions to prevent the tendency of
the wheel to lock by controlling the brake
hydraulic pressure. But, if there is a tendency
of the wheel to lock on a slippery road surface,
due to engine braking, the ABS may not be
able to prevent the wheel from locking.
WARNING
_
The ABS controls only the tendency of the
wheel to lock caused by applying the
brakes. The ABS cannot prevent wheel lock
on slippery surfaces, such as ice, when it is
caused by engine braking, even if the ABS
is operating.
Brake force
Side force
Slip ratio (%)
Friction force between the tire and road surface

1 - 9
GEN
INFO
FEATURES
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ABS component functions
•Wheel sensors and sensor rotors
Wheel sensors 1detect the wheel rotation
speed and transmit the wheel rotation signal to
the ECU (ABS).
Each wheel sensor is composed of a perma-
nent magnet and a coil. The wheel sensors are
installed in the sensor housing for each wheel.
Sensor rotors 2are installed inside the front
and rear wheel hubs and rotate with the
wheels. Each sensor rotor has 40 serrations
that face the sensor housing. As the distance
changes between the top and bottom of the
serrations with the rotation of the wheels,
inductive electromotive force is generated in
the wheel sensors. Wheel rotation speed is
detected based on the frequency of this alter-
nating voltage.
3At high speed
4At low speed
5Wheel sensor
6Sensor rotor
1
2
2
1
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•Hydraulic unit
The hydraulic unit 1is composed of a hydrau-
lic control valve (solenoid valve, flow control
valve), a buffer chamber, and a hydraulic
pump for each brake and an ABS motor. The
hydraulic unit adjusts the front and rear wheel
brake fluid pressure to control the wheel rota-
tion speed according to signals transmitted
from the ECU (ABS).
1