Yamaha YZF-R125 Service Manual: Troubleshooting

Yamaha YZF-R125 Service Manual / Electrical system / Signaling system / 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

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 ...

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 the valve seats
The following procedure applies to all of the valves and valve seats. 1. Eliminate: Carbon deposits (from the valve face and valve seat) 2. Check: Valve seat Pitting/wear Replace the cylinder head. 3. Measure: Valve seat width C "a" Out of specification Replace the ...

Checking the piston rings
1. Measure: Piston ring side clearance Out of specification Replace the piston and piston rings as a set. NOTE: Before measuring the piston ring side clearance, eliminate any carbon deposits from the piston ring grooves and piston rings. 2. Install: Piston ring (into the cylind ...