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 and lubricating the cables
The following procedure applies to all of the inner
and outer cables.
WARNINGDamaged outer cable may cause the cable to
corrode and interfere with its movement. Replace
damaged outer cable and inner cables
as soon as possible.
1. Check:
Outer cable
Damage Replace.
2 ...
Checking the spark plug
1. Remove:
Right side cover
Refer to "GENERAL CHASSIS" on page 4-1.
2. Disconnect:
Spark plug cap
3. Remove:
Spark plug
CAUTION:Before removing the spark plug, blow away
any dirt accumulated in the spark plug well
with compressed air to prevent it from falling
...
Rider seat
To remove the rider seat
Insert the key into the seat lock,
and then turn it clockwise.
Seat lock
Open.
Pull the rider seat off.
To install the rider seat
1. Insert the projection on the front of
the rider seat into the seat holder
as shown.
Projection
...