Yamaha YZF-R125 Service Manual: Fuel pump system
Troubleshooting details
This section describes the measures per fault code number displayed on the FI
diagnostic tool. Check
and service the items or components that are the probable cause of the
malfunction following t ...
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 ...
Other materials:
Overheating
Engine
1. Clogged coolant passages
Cylinder head and piston
Heavy carbon buildup
2. Engine oil
Incorrect oil level
Incorrect oil viscosity
Inferior oil quality
Cooling system
1. Coolant
Low coolant level
2. Radiator
Damaged or leaking radiator
Faulty radiator cap
...
Installing the starter clutch
1. Install:
Starter clutch assembly
Starter clutch bolts "1"
NOTE:
While holding the generator rotor "2" with the
sheave holder "3", tighten the starter clutch
bolts.
Do not allow the sheave holder to touch the
projection on the generator rotor.
Stake the end "a" of each start ...
Checking the rectifier/regulator
1. Check:
Rectifier/regulator output voltage
Out of specification → Replace the
rectifier/
regulator.
a. Set the engine tachometer to the spark plug
lead.
b. Connect the pocket tester (DC 20 V) to the
rectifier/regulator coupler as shown.
Positive tester probe
red "1"
Negat ...