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 camshaft
1. Check:
Camshaft lobes
Blue discoloration/pitting/scratches
Replace
the camshaft.
2. Measure:
Camshaft lobe dimensions "a" and "b"
Out of specification Replace
the camshaft.
3. Check:
Camshaft oil passage
Obstruction Blow out with
compressed air. ...
Checking the valves and valve guides
The following procedure applies to all of the
valves and valve guides.
1. Measure:
Valve-stem-to-valve-guide clearance
Out of specification Replace the
valve
guide.
Valve-stem-to-valve-guide clearance =
Valve guide inside diameter "a" -
Valve stem diameter "b"
2. Replace:
...
Replacing the air filter element and cleaning the check hose
The air filter element should be replaced
at the intervals specified in the
periodic maintenance and lubrication
chart. Have a Yamaha dealer replace
the air filter element more frequently if
you are riding in unusually wet or dusty
areas. In addition, the air filter check
hose must be ...