Yamaha YZF-R125 Service Manual: Faulty clutch
Clutch slips
1. Clutch
- Improperly assembled clutch
- Improperly adjusted clutch cable
- Loose or fatigued clutch spring
- Worn friction plate
- Worn clutch plate
2. Engine oil
- Incorrect oil level
- Incorrect oil viscosity (low)
- Deteriorated oil
Clutch drags
1. Clutch
- Unevenly tensioned clutch springs
- Warped pressure plate
- Bent clutch plate
- Swollen friction plate
- Bent clutch push rod
- Broken clutch boss
- Burnt primary driven gear bushing
2. Engine oil
- Incorrect oil level
- Incorrect oil viscosity (high)
- Deteriorated oil
Jumps out of gear
Shift shaft
Incorrect shift pedal position
Improperly returned stopper lever
Shift forks
Worn shift fork
Shift drum
Incorrect axial play
Worn shift drum groove
Transmission
...
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. ...
Other materials:
Checking the horn
1. Check:
Horn resistance
Out of specification Replace.
a. Disconnect the horn connectors from the
horn terminals.
b. Connect the pocket tester ( × 1) to the horn
terminals.
Positive tester probe
horn terminal "1"
Negative tester probe
horn terminal "2"
c. Measure t ...
Checking the rear brake hose
1. Check:
Brake hoses "1"
Cracks/damage/wear
Replace.
2. Check:
Brake hose holder "2"
Loose connection Tighten the
holder bolt.
Loose or open holder Fasten
properly.
3. Hold the vehicle upright and apply the rear
brake several times.
4. Check:
Brake ho ...
Removing the crankshaft
1. Remove:
Crankshaft "1"
NOTE:
Remove the crankshaft with the crankcase
separating tool "2".
Make sure the crankcase separating tool is
centered over the crankshaft.
CAUTION:
To protect the end of the crankshaft, place
an appropriate sized socket between the
c ...