maintenance YAMAHA XTZ125 2003 User Guide

6-12
6-12Valve clearance adjustment
The correct valve clearance changes with use, resulting in
improper fuel/air supply or engine noise. To prevent this,
valve clearance must be adjusted regularly. This adjustment,
however, should be left to a professional Yamaha service
technician. Carburetor adjustment
The carburetor is a vital part of the engine. Adjusting should
be left to a Yamaha dealer who has the professional
knowledge, specialized data, and equipment to do so
properly. However, the following may be serviced by the
owner as part of routine maintenance.
CAUTION:
The carburetor was set at Yamaha factory after many
tests. If the settings are changed, poor engine
performance and damage may result.
Valve clearance adjustment
The correct valve clearance changes with use, resulting in
improper fuel/air supply or engine noise. To prevent this,
valve clearance must be adjusted regularly. This adjustment,
however, should be left to a professional Yamaha service
technician. Carburetor adjustment
The carburetor is a vital part of the engine. Adjusting should
be left to a Yamaha dealer who has the professional
knowledge, specialized data, and equipment to do so
properly. However, the following may be serviced by the
owner as part of routine maintenance.
CAUTION:
The carburetor was set at Yamaha factory after many
tests. If the settings are changed, poor engine
performance and damage may result.

6-23
6-23 3. Refill with the same type of brake fluid. Mixing fluids
may result in a harmful reaction and lead to poor brake
performance.
4. Be careful that water does not enter the master cylinder
when refilling. Water will significantly lower the boiling
point of the fluid and may result in vapor lock.
5. Brake fluid may deteriorate painted surfaces or plastic
parts. Always clean up spilled fluid immediately.
6. Have a Yamaha dealer check the cause if the brake
fluid level goes down.1. Complete fluid replacement should be done only by
trained service personnel.
2. Have a Yamaha dealer replace the following
components during periodic maintenance or when they
are damaged or leaking.
a. Replace all rubber seals every two years.
b. Replace all hoses every four years. Brake fluid replacement
3. Refill with the same type of brake fluid. Mixing fluids
may result in a harmful reaction and lead to poor brake
performance.
4. Be careful that water does not enter the master cylinder
when refilling. Water will significantly lower the boiling
point of the fluid and may result in vapor lock.
5. Brake fluid may deteriorate painted surfaces or plastic
parts. Always clean up spilled fluid immediately.
6. Have a Yamaha dealer check the cause if the brake
fluid level goes down.1. Complete fluid replacement should be done only by
trained service personnel.
2. Have a Yamaha dealer replace the following
components during periodic maintenance or when they
are damaged or leaking.
a. Replace all rubber seals every two years.
b. Replace all hoses every four years. Brake fluid replacement

6-31
6-31
Wheel bearings
If there is play in the front or rear wheel hub or if the wheel
does not turn smoothly, have a Yamaha dealer inspect the
wheel bearings. The wheel bearings should be inspected
according to the Maintenance Schedule. Steering inspection
Securely support the motorcycle so there is no danger
of it falling over. Periodically inspect the condition of the steering. Worn out
or loose steering bearings may be dangerous. Place a stand
under the engine to raise the front wheel off the ground.
Hold the lower end of the front forks and try to move them
forward and backward. If any free play can be felt, ask a
Yamaha dealer to inspect and adjust the steering. Inspection
is easier if the front wheel is removed.
WARNING:
Wheel bearings
If there is play in the front or rear wheel hub or if the wheel
does not turn smoothly, have a Yamaha dealer inspect the
wheel bearings. The wheel bearings should be inspected
according to the Maintenance Schedule. Steering inspection
Securely support the motorcycle so there is no danger
of it falling over. Periodically inspect the condition of the steering. Worn out
or loose steering bearings may be dangerous. Place a stand
under the engine to raise the front wheel off the ground.
Hold the lower end of the front forks and try to move them
forward and backward. If any free play can be felt, ask a
Yamaha dealer to inspect and adjust the steering. Inspection
is easier if the front wheel is removed.
WARNING: