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 the switches
1. Clutch switch
2. Main switch
3. Front brake light switch
4. Sidestand switch
5. Rear brake light switch
6. Neutral switch
7. Turn signal switch
8. Horn switch
9. Dimmer switch
10.Pass switch
11.Engine stop switch
12.Start switch
Check each switch for continuity with the pocket tes ...
Checking the clutch plates
The following procedure applies to all of the
clutch plates.
1. Check:
Clutch plate
Damage Replace the clutch
plates as a
set.
2. Measure:
Clutch plate warpage
(with a surface plate and thickness gauge "1")
Out of specification Replace
the clutch
plates as a set.
...
Checking the fuses
The following procedure applies to all of the fuses.
CAUTION:To avoid a short circuit, always turn the
main
switch to "OFF" when checking or replacing
a fuse.
1. Remove:
Rider seat
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Fuse
a. Connect the pocket te ...