Yamaha YZF-R125 Service Manual: General information
NOTE:
The following guide for troubleshooting does not cover all the possible causes of trouble. It should be helpful, however, as a guide to basic troubleshooting.
Refer to the relative procedure in this manual for checks, adjustments, and replacement of parts.
Troubleshooting
...
Starting failures
Engine
1. Cylinder and cylinder head
- Loose spark plug
- Loose cylinder head or cylinder
- Damaged cylinder head gasket
- Damaged cylinder gasket
- Worn or damaged cylinder
- Incorrect valve c ...
Other materials:
Checking the starter clutch
1. Check:
Starter clutch rollers "1"
Starter clutch spring caps "2"
Starter clutch springs "3"
Damage/wear Replace the starter
clutch
assembly.
2. Check:
Starter clutch idle gear
Starter clutch gear
Burrs/chips/roughness/wear Replace the
defective part(s).
3. Check:
...
Fi system
The fuel pump delivers fuel to the fuel injector via the fuel filter. The
pressure regulator maintains the
fuel pressure that is applied to the fuel injector at only 250 kPa (2.50 kg/cm²,
36.3 psi). Accordingly,
when the energizing signal from the ECU energizes the fuel injector, the fuel ...
Checking the ignition coil
1. Check:
Primary coil resistance
Out of specification Replace.
a. Disconnect the ignition coil connectors from
the ignition coil terminals.
b. Connect the pocket tester ( × 1)
to the ignition
coil as shown.
Positive tester probe
red/white "1"
Negative tester probe
orange ...