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:
Identification numbers
Record the key identification number,
vehicle identification number and model
label information in the spaces provided
below for assistance when
ordering spare parts from a Yamaha
dealer or for reference in case the vehicle
is stolen.
KEY IDENTIFICATION NUMBER:
VEHICLE IDENTIFICATION ...
Removing the front wheel (disc)
1. Stand the vehicle on a level surface.
WARNINGSecurely support the vehicle so that there
is
no danger of it falling over.
2. Elevate:
Front wheel
NOTE:
Place the vehicle on a suitable stand so that the
front wheel is elevated.
3. Remove:
Front brake caliper
NO ...
Troubleshooting
Any of the following fail to light: turn signal lights, brake light or
indicator lights.
The horn fails to sound.
The fuel gauge fails to operate.
The speedometer fails to operate.
NOTE:
Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
3. Left upper ...