Inspect the needle bearing bore surface on the basket next. Run your fingernail across the bore feeling for signs of wear. The bearing surface should be smooth and free of imperfections. If the surface is grooved or worn the basket will need to be replaced.
If any grooving is present, use the end of a pick to evaluate how deep the grooves are. Any grooving that can catch the end of the pick is also likely to be able to catch the edge of the clutch discs. When this happens, the clutch will have difficulty engaging and disengaging. If your bike had clutch disengagement/engagement problems prior to disassembly, basket grooving is the most probable cause.
Some manufacturers provide a specification for the clearance between the clutch disc tang and the basket fingers. This clearance can be measured by temporarily installing a clutch disc into the basket and using a set of lash gauges to check the clearance between the two parts. Both the clutch disc tangs and basket fingers will wear so if the clearance is outside the service limit it may be possible to prolong the life of the basket by installing new clutch discs. This is a short term fix however, and replacing both components at once is advisable.
Pressure Plate Inspection
Disc and Plate Inspection
Clutch Disc and Clutch Plate Inspection
Lastly, inspect the clutch disc tangs for wear, chipping, or damage. If any tangs are damaged the disc should be replaced.
Clutch Spring Inspection
I hope you enjoyed this passage from my book detailing clutch inspection. If you have additional tips you'd like to share please leave a comment!
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