Yamaha YZF-R125 Service Manual: Checking the rear brake disc
1. Remove:
- Rear wheel Refer to "REAR WHEEL" on page 4-12.
2. Check:
- Brake disc Damage/galling → Replace.
3. Measure:
Brake disc deflection Out of specification → Correct the brake disc deflection or replace the brake disc.
Refer to "CHECKING THE FRONT BRAKE
DISC" on page 4-21. 
4. Measure:
Brake disc thickness Measure the brake disc thickness at a few different locations.
Out of specification → Replace.
Refer to "CHECKING THE FRONT BRAKE
DISC" on page 4-21. 
5. Adjust:
- Brake disc deflection
Refer to "CHECKING THE FRONT BRAKE
DISC" on page 4-21.
6. Install:
- Rear wheel Refer to "REAR WHEEL" on page 4-12.
Introduction
WARNINGDisc brake components rarely require
disassembly.
Therefore, always follow these preventive
measures:
Never disassemble brake components unless
absolutely necessa ...
Replacing the rear brake pads
NOTE:
When replacing the brake pads, it is not necessary
to disconnect the brake hose or disassemble
the brake caliper.
1. Remove:
Brake pads
Brake pad spring
NOTE:
To remove the inner b ...
Other materials:
Setting the diagnostic mode
1. Set the main switch to "OFF" and the engine stop switch to "
".
2. Disconnect the self-diagnosis signal connector "1", and then connect the FI
diagnostic tool "2" as
shown.
3. Disconnect the fuel pump coupler.
4. While pressing the "MODE" button, set the main switch to "ON".
NOTE:
...
Adjusting the drive chain slack
NOTE:
The drive chain slack must be checked at the
tightest point on the chain.
CAUTION:A drive chain that is too tight will
overload
the engine and other vital parts, and one that
is too loose can skip and damage the swingarm
or cause an accident. Therefore, keep
the drive ...
Replacing the fuses
Replacing the fuses
Fuse box
Spare fuse
Headlight fuse
Signaling system fuse
Ignition fuse
Radiator fan fuse
Main fuse
The fuse box is located under the rider
seat.
If a fuse is blown, replace it as follows.
Turn the key to "OFF" and turn off
the electrical circuit i ...