Yamaha YZF-R125 Service Manual: Circuit diagram
4. Main fuse
5. Main switch
9. Battery
17.Engine stop switch
25.ECU (engine control unit)
30.Fuel pump
64.Ignition fuse
Fuel pump system
...
Troubleshooting
If the fuel pump fails to operate.
NOTE:
Before troubleshooting, remove the following part(s):
1. Rider seat
2. Fuel tank
...
Other materials:
Faulty lighting or signaling system
Headlight does not come on
- Wrong headlight bulb
- Too many electrical accessories
- Hard charging
- Incorrect connection
- Improperly grounded circuit
- Poor contacts (main or light switch)
- Burnt-out headlight bulb
Headlight bulb burnt out
- Wrong headlight bulb
- Faulty battery
- Fau ...
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 pin
1. Check:
Piston pin
Blue discoloration/grooves
Replace the
piston pin and then check the lubrication system.
2. Measure:
Piston pin outside diameter "a"
Out of specification Replace
the piston pin.
3. Measure:
Piston pin bore diameter "b"
Out of specifica ...