Yamaha YZF-R125 Service Manual: Checking the speed sensor
1. Check:
Speed sensor output voltage
Out of specification → Replace.
a. Connect the pocket tester (DC 20 V) to the
speed sensor coupler (wire harness end) as
shown.
- Positive tester probe gray "1"
- Negative tester probe gray/black "2"
b. Set the main switch to "ON".
c. Elevate the front wheel and slowly rotate it.
d. Measure the voltage of gray and gray/black.
With each full rotation of the front wheel, the voltage reading should cycle from 0 V to 5.0 V to 0 V to 5.0 V.
Checking the fuel sender
1. Drain the fuel from the fuel tank.
2. Check:
Fuel sender resistance
Out of specification → Replace the fuel
sender.
a. Connect the pocket tester ( ×
10) to the fuel
sender c ...
Checking the radiator fan motor
1. Check:
Radiator fan motor
Faulty/rough movement → Replace.
a. Disconnect the radiator fan motor coupler
from the wire harness.
b. Connect the battery (DC 12 V) as shown.
Posi ...
Other materials:
Checking and adjusting the steering head
1. Stand the vehicle on a level surface
WARNINGSecurely support the vehicle so that there
is
no danger of it falling over.
NOTE:
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 an ...
Checking the rear brake caliper
1. Check:
Brake caliper piston "1"
Rust/scratches/wear Replace the
brake
caliper piston.
Brake caliper cylinder "2"
Scratches/wear Replace the
brake caliper
assembly.
Brake caliper body "3"
Cracks/damage Replace the
brake caliper
assembly.
Brake fluid deli ...
General chassis
Installing the air filter case
1. Install:
Air filter case joint clamp
NOTE:
Align the projection "a" on the air filter case with
the slot "b" in the air filter case joint clamp.
...