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 shift shaft
1. Check:
Shift shaft
Bends/damage/wear Replace.
Shift shaft spring
Damage/wear Replace.
Checking the stopper lever
1. Check:
Stopper lever
Bends/damage Replace.
Roller turns roughly Replace
the stopper
lever.
Stopper lever spring
Damage/wear Replace.
...
Checking the diode
1. Check:
Diode
Out of specification Replace.
NOTE:
The pocket tester or the analog pocket tester
readings are shown in the following table.
a. Disconnect the diode from the wire harness.
b. Connect the pocket tester ( × 1)
to the diode
terminals as shown.
c. Check the diod ...
Cast wheels
To maximize the performance, durability,
and safe operation of your vehicle,
note the following points regarding the
specified wheels.
The wheel rims should be checked
for cracks, bends or warpage before
each ride. If any damage is
found, have a Yamaha dealer replace
the wheel. ...