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

Troubleshooting


Troubleshooting


Troubleshooting


    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:

    Installing the water pump
    1. Install: Water pump assembly "1" O-rings "2" NOTE: Align the projection "a" on the impeller shaft with the slit "b" on the camshaft sprocket bolt. Lubricate the O-rings with a thin coat of lithiumsoap- based grease. 2. Fill: Cooling system (with the specified amou ...

    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 ...

    Checking the lean angle sensor
    1. Remove: Lean angle sensor 2. Check: Lean angle sensor output voltage Out of specification Replace. a. Connect the lean angle sensor to the wire harness. b. Connect the pocket tester (DC 20 V) to the lean angle sensor coupler as shown. Positive tester probe yellow/green "1" Neg ...

    2026 Copyright www.yam-r125.net |