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 horn
1. Check:
Horn resistance
Out of specification Replace.
a. Disconnect the horn connectors from the
horn terminals.
b. Connect the pocket tester ( × 1) to the horn
terminals.
Positive tester probe
horn terminal "1"
Negative tester probe
horn terminal "2"
c. Measure t ...
Checking the cylinder and piston
1. Check:
Piston wall
Cylinder wall
Vertical scratches Replace the
cylinder,
and replace the piston and piston rings as a
set.
2. Measure:
Piston-to-cylinder clearance
a. Measure cylinder bore "C" with the cylinder
bore gauge.
NOTE:
Measure cylinder bore "C" by takin ...