Yamaha YZF-R125 Service Manual: Troubleshooting
- Any of the following fail to light: turn signal lights, brake light or indicator lights.
- The horn fails to sound.
- The fuel gauge fails to operate.
- The speedometer fails to operate.
NOTE:
- Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
3. Left upper side cowling
4. Right side panel
5. Left lower side cowling
Circuit diagram
4. Main fuse
5. Main switch
9. Battery
14.Neutral switch
25.ECU (engine control unit)
31.Fuel sender
34.Rear brake light switch
35.Front brake light switch
37.Tail/brake light
38.Rear rig ...
Cooling system
...
Other materials:
Checking the primary driven gear
1. Check:
Primary driven gear "1"
Damage/wear Replace the
primary drive
gear and clutch housing as a set.
Excessive noise during operation
Replace
the primary drive gear and clutch housing as
a set.
...
Faulty front fork legs
Leaking oil
- Bent, damaged or rusty inner tube
- Cracked or damaged outer tube
- Improperly installed oil seal
- Damaged oil seal lip
- Incorrect oil level (high)
- Loose damper rod assembly bolt
- Damaged damper rod assembly bolt copper
washer
- Cracked or damaged front fork cap O-ring
M ...
Throttle position sensor
1. Check:
Throttle position sensor
a. Connect the digital circuit tester to the terminals
of the throttle body sensor assembly
coupler as shown.
Positive tester probe →
gray/red terminal "1"
Negative tester probe →
gray/black terminal "2"
b. Measure the throttle pos ...