Yamaha YZF-R125 Service Manual: Checking the front brake disc
1. Remove:
- Front wheel Refer to "FRONT WHEEL" on page 4-6.
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.
a. Place the vehicle on a suitable stand so that the front wheel is elevated.
b. Before measuring the front brake disc deflection, turn the handlebar to the left or right to ensure that the front wheel is stationary.
c. Remove the brake caliper.
d. Hold the dial gauge at a right angle against the brake disc surface.
e. Measure the deflection 1.5 mm (0.06 in) below the edge of the brake disc.
4. Measure:
- Brake disc thickness
Measure the brake disc thickness at a few different
locations.
Out of specification
Replace.
5. Adjust:
- Brake disc deflection
a. Remove the brake disc.
b. Rotate the brake disc by one bolt hole.
c. Install the brake disc.
NOTE:
Tighten the brake disc bolts in stages and in a crisscross pattern.
d. Measure the brake disc deflection.
e. If out of specification, repeat the adjustment steps until the brake disc deflection is within specification.
f. If the brake disc deflection cannot be brought within specification, replace the brake disc.
6. Install:
- Front wheel Refer to "FRONT WHEEL" on page 4-6.
Introduction
WARNINGDisc brake components rarely require
disassembly.
Therefore, always follow these preventive
measures:
Never disassemble brake components unless
absolutely necessa ...
Replacing the front brake pads
NOTE:
When replacing the brake pads, it is not necessary
to disconnect the brake hose or disassemble
the brake caliper.
1. Measure:
Brake pad wear limit "a"
Out of specification Replace
...
Other materials:
Checking the fuel line
1. Remove:
Left side panel
Refer to "GENERAL CHASSIS" on page 4-1.
2. Lift the fuel tank. (Do not disconnect the fuel
hose, drain hose
3. Check:
Fuel hose "1"
Cracks/damage → Replace.
Loose connection Connect properly.
4. Install:
Fuel tank
Refer to "FUEL TANK" on pa ...
Checking the friction plates
The following procedure applies to all of the friction
plates.
1. Check:
Friction plate
Damage/wear Replace the
friction plates
as a set.
2. Measure:
Friction plate thickness
Out of specification Replace
the friction
plates as a set.
NOTE:
Measure the friction plate ...
Removing the valves
The following procedure applies to all of the
valves and related components.
NOTE:
Before removing the internal parts of the cylinder
head (e.g., valves, valve springs, valve seats),
make sure the valves properly seal.
1. Check:
Valve sealing
Leakage at the valve seat Check
the valve
...