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:
Installing the clutch
1. Install:
Conical spring washer "1"
NOTE:
Install the conical spring washer as shown in the
illustration.
2. Install:
Clutch housing
Thrust washer "1"
NOTE:
Be sure to install the thrust washer so that its
sharp edge "a" is facing away from the clutch
boss.
3. Instal ...
Installing the starter clutch
1. Install:
Starter clutch assembly
Starter clutch bolts "1"
NOTE:
While holding the generator rotor "2" with the
sheave holder "3", tighten the starter clutch
bolts.
Do not allow the sheave holder to touch the
projection on the generator rotor.
Stake the end "a" of each start ...
Checking and replacing the rear wheel sprocket
1. Check:
Rear wheel sprocket
More than 1/4 tooth "a" wear
Replace the
rear wheel sprocket.
Bent teeth Replace the rear
wheel sprocket.
b. Correct
1. Drive chain roller
2. Rear wheel sprocket
2. Replace:
Rear wheel sprocket
a. Remove the self-locking nuts and the ...