Join Date: Jun 2018
Location: Hawke's Bay, New Zealand
So when you had the plug out and you spin the rear wheel the piston goes up and down?
Regarding the clutch drum: The clutch drum is supposed to be evenly round and not touch the clutch shoes when motor is not running. This should only happen at very high revs.
The crank drives the clutch shoes and when the revs are high enough, so the centrifugal force expands the clutch springs, the clutch shoes grab the drum that is driving the output shaft where the front sprocket is fitted. When turning the back wheel (w/o motor running) it should spin freely as the drum (that will spin from you turning the back wheel) does not touch the clutch shoes.
No, I have not seen a warped clutch drum. But your bike is 20 years old and it could have had a tough life in those years.
You will need to have a really close look at the whole setup to figure out what is causing this.
When going by your description in your first post "....wont free spin..." I concluded that something is stopping the clutch drum from not freely spinning while motor is not running. You also tell us that the clutch shoes had come loose and damaged the side cover. This clearly had happened at high revs (reason for the damage to the side cover) so that could also have damaged other parts.
If you take the clutch shoes and their mounting off there should be nothing that makes the piston move when you spin the back wheel.
Probable issues causing all this:
- The output shaft from the crank is bent
- The r/h crank main bearing is worn/damaged allowing the shaft to move.
- You are missing some parts of the clutch that now makes the clutch shoe mounting and the drum bind.
- The clutch shoes are not fitted properly, or they are the wrong shoes.
- Or is there some damage to the drum?
- The drum is not spinning freely on the output shaft from the crank
If this bike was in my workshop I would start by taking the clutch shoes and their mounting off and then check the drum and the output shaft from the crank for damage, that the main bearing is all good and that the output shaft is not bent. I would spin the backwheel with the clutch off to satisfy myself that all was running freely. I would then make sure that I actually have all the bits that are to be fitted together with the drum and the clutch. And satisfy myself that they are all in good order (if not I would replace any faulty ones). If this was the first time I worked on a setup like this I would find a manual for the job on the net and follow any instructions re how all this goes together. (There is a link on this page to manuals, but they are available at many sites)
Come back and tell us how you are getting on and if you have some other things we can help with please ask.
.................................................LET THE BRIDGES I BURN LIGHT THE WAY!
Last edited by Axzon; 07-11-2019 at 02:54 PM.