Yamaha YP125R Service Manual

CHASSIS
3-37
• When bleeding the hydraulic brake system,
make sure there is always enough brake fluid
before applying the brake. Ignoring this pre-
caution could allow air to enter the hydraulic
brake system, considerably lengthening the
bleeding procedure.
• If bleeding is difficult, it may be necessary to let
the brake fluid settle for a few hours. Repeat
the bleeding procedure when the tiny bubbles
in the hose have disappeared.
1. Bleed:
• Hydraulic brake system
▼▼▼▼▼▼▼▼▼ ▼ ▼▼▼▼▼▼▼▼▼ ▼ ▼▼▼▼ ▼ ▼▼▼▼ ▼▼▼
a. Fill the brake master cylinder reservoir to the
proper level with the recommended brake flu-
id.
b. Install the brake master cylinder reservoir di-
aphragm.
c. Connect a clear plastic hose “1” tightly to the
bleed screw “2”.
d. Place the other end of the hose into a con-
tainer.
e. Slowly apply the brake several times.
f. Fully pull the brake lever and hold it in posi-
tion.
g. Loosen the bleed screw.
T
IP
Loosening the bleed screw will release the pres-
sure and cause the brake lever to contact the
throttle grip or handlebar grip.
h. Tighten the bleed screw, and then release
the brake lever.
i. Repeat steps (e) to (h) until all of the air bub-
bles have disappeared from the brake fluid in
the plastic hose.
j. Tighten the bleed screw to specification.
k. Fill the brake master cylinder reservoir to the
proper level with the recommended brake flu-
id.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-35.
WARNING
EWA13110
After bleeding the hydraulic brake system,
check the brake operation.
▲▲▲▲▲▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲ ▲▲▲▲ ▲▲▲
EAS21510
CHECKING AND ADJUSTING THE
STEERING HEAD
1. Stand the vehicle on a level surface.
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
T
IP
Place the vehicle on a suitable stand so that the
front wheel is elevated.
2. Check:
• Steering head
Grasp the bottom of the front fork legs and
gently rock the front fork.
A. Front brake caliper
B. Rear brake caliper (YP125R)
C. Rear brake caliper (YP250R)
1
2
A
2
1
B
2
1
C
T
R
.
.
Front brake caliper bleed screw
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
Rear brake caliper bleed screw
(YP125R)
14 Nm (1.4 m·kgf, 10 ft·lbf)
Rear brake caliper bleed screw
(YP250R)
6 Nm (0.6 m·kgf, 4.3 ft·lbf)

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)