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
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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 front and rear brake pads
The front and rear brake pads must be
checked for wear at the intervals specified
in the periodic maintenance and
lubrication chart.
Front brake pads
Remove the front brake caliper by
removing the bolts.
Bolt
Brake caliper
Lining thickness
Check each front br ...
Installing the shift forks and shift drum assembly
1. Install:
Shift fork-L "1"
Shift fork-C "2"
Shift fork-R "3"
Shift drum assembly "4"
Springs
Shift fork guide bar "5"
NOTE:
The embossed marks on the shift forks should
face towards the right side of the engine and be
in the following sequence: "R", "C", "L".
2. Check:
Tr ...
Checking the cylinder head breather hose
1. Remove:
Left side panel
Refer to "GENERAL CHASSIS" on page 4-1.
2. Check:
Cylinder head breather hose "1"
Cracks/damage → Replace.
Loose connection → Connect properly.
CAUTION:Make sure the cylinder head
breather hose is
routed correctly.
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