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:
General maintenance and lubrication chart
TIP
The air filter needs more frequent service if you are riding in
unusually wet or dusty areas.
Hydraulic brake service
Regularly check and, if necessary, correct the brake fluid level.
Every two years change the brake fluid.
Replace the brake hoses every four ye ...
Checking the spark plug
1. Remove:
Right side cover
Refer to "GENERAL CHASSIS" on page 4-1.
2. Disconnect:
Spark plug cap
3. Remove:
Spark plug
CAUTION:Before removing the spark plug, blow away
any dirt accumulated in the spark plug well
with compressed air to prevent it from falling
...
Installing the swingarm
1. Lubricate:
Bearings
Spacers
Dust covers
Pivot shaft
2. Install:
Bearings "1"
2. Swingarm
A. Left side
B. Right side
3. Install:
Swingarm adjusting collar "1"
Swingarm "2"
Pivot shaft
Pivot shaft nut "3"
a. Install, and then fully turn in the swingarm adju ...