Yamaha YZF-R125 Service Manual: Electrical components
1. Main switch
2. Clutch switch
3. Front brake light switch
4. Ignition coil
5. Throttle body sensor assembly (intake air pressure sensor, intake air temperature sensor, throttle position sensor)
6. FID (fast idle solenoid)
7. Rectifier/regulator
8. Lean angle sensor
9. Starting circuit cut-off relay
10.Turn signal relay
11.Radiator fan motor relay
12.Headlight relay
13.ECU (engine control unit)
14.Fuse box
15.Starter relay
16.Battery
17.Rear brake light switch
18.Sidestand switch
19.Neutral switch
20.Crankshaft position sensor
21.Coolant temperature sensor
22.Speed sensor
23.Radiator fan
24.Horn
- Checking the switches
- Checking the bulbs and bulb sockets
- Checking the fuses
- Checking and charging the battery
- Checking the relays
- Checking the turn signal relay
- Checking the diode
- Checking the spark plug cap
- Checking the ignition coil
- Checking the ignition spark gap
- Checking the crankshaft position sensor
- Checking the lean angle sensor
- Checking the starter motor operation
- Checking the stator coil
- Checking the rectifier/regulator
- Checking the horn
- Checking the fuel sender
- Checking the speed sensor
- Checking the radiator fan motor
- Checking the coolant temperature sensor
- Checking the throttle body sensor assembly
- Checking the fid (fast idle solenoid)
Troubleshooting
If the fuel pump fails to operate.
NOTE:
Before troubleshooting, remove the following part(s):
1. Rider seat
2. Fuel tank
...
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 ...
Other materials:
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 ...
Replacing an auxiliary light bulb
This model is equipped with two auxiliary
lights. If an auxiliary light bulb burns
out, replace it as follows.
Remove the socket (together with
the bulb) by pulling it out.
Auxiliary light bulb
Remove the burnt out bulb by pulling
it out.
Insert a new bulb into t ...
Checking the rocker arms and rocker arm shafts
The following procedure applies to all of the
rocker arms and rocker arm shafts.
1. Check:
Rocker arm
Damage/wear Replace.
2. Check:
Rocker arm shaft
Blue discoloration/excessive wear/pitting/
scratches Replace or
check the lubrication
system.
3. Measure:
Rocke ...