Yamaha YP125R Service Manual

FRONT BRAKE
4-22
EAS22220
INTRODUCTION
WARNING
EWA14101
Disc brake components rarely require disas-
sembly. Therefore, always follow these pre-
ventive measures:
• Never disassemble brake components un-
less absolutely necessary.
• If any connection on the hydraulic brake
system is disconnected, the entire brake
system must be disassembled, drained,
cleaned, properly filled, and bled after reas-
sembly.
• Never use solvents on internal brake com-
ponents.
• Use only clean or new brake fluid for clean-
ing brake components.
• Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
• Avoid brake fluid coming into contact with
the eyes as it can cause serious injury.
FIRST AID FOR BRAKE FLUID ENTERING
THE EYES:
• Flush with water for 15 minutes and get im-
mediate medical attention.
EAS22230
CHECKING THE FRONT BRAKE DISC
1. Remove:
• Front wheel
Refer to “FRONT WHEEL” on page 4-9.
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.
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a. Place the vehicle on a suitable stand so that
the front wheel is elevated.
b. Before measuring the front brake disc deflec-
tion, 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) be-
low the edge of the brake disc.
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4. Measure:
• Brake disc thickness
Measure the brake disc thickness at a few dif-
ferent locations.
Out of specification → Replace.
5. Adjust:
• Brake disc deflection
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a. Remove the brake disc.
b. Rotate the brake disc by one bolt hole.
c. Install the brake disc.
T
IP
Tighten the brake disc bolts in stages and in a
crisscross pattern.
Brake disc deflection limit
0.15 mm (0.0059 in)
Brake disc thickness limit
4.5 mm (0.18 in)
T
R
.
.
Front brake disc bolt
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
LOCTITE®

Yamaha YP125R Specifications

General

Engine Type	Liquid-cooled, 4-stroke, SOHC, 4-valve
Bore x Stroke	52.4 mm x 57.9 mm
Fuel System	Fuel Injection
Ignition System	TCI
Transmission	V-Belt Automatic
Front Suspension	Telescopic fork
Rear Suspension	Unit Swing
Front Brake	Hydraulic single disc, Ø267 mm
Starter System	Electric
Rear Tyre	140/70-14M/C 62P (Tubeless)