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Clutch noise

The savage

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Hello dont know if anyone can help I have a 92 cb750. When I engage the clutch it really rattles after th revs pick up it's fine, changing gear on the go is fine also. Drop down to a speed which would normally be too slow for the gear your in it does the same. The problem started after I changed the reg/rec then it wouldn't start. After much cranking and misfiring I discovered I had disconnected a wire on one of the coils. Restarted with horrible noises, rattling and slapping. I changed the cam chain which stopped the slapping noise but I have a slight rattle from the alternator which stops when it's under load ( not too worried ) but this is where the awful noise seems to come from when I pull away. So I guess I'm asking whether anyone can tell me if this is the alternator chain or something to do with the clutch or something else. Don't think the carbs are that out of balance as it was fine beforehand. Any help most appreciated.
 
'...it was fine beforehand.'

Look at the work done there. If the camchain was worn enough to need changing then for sure any tensioners/guides running against it needed the same. Not doing that could easily modify the noises to be different. Same with very worn chain sprockets, the worn chain wears them too and then a new chain still makes noise of some sort.

Don't know if that one incorporates a riveted clutch 'shock' plate like some have in the past, doing so with loose or missing plate rivets can make that noise too.
 
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The manual shows a different steel clutch plate at one position but does not say whether it is rivetted. The outer clutch housing can be loose too to make noise, there is no jackshaft on these to make noise with carbs not being synced well. There is an alternator chain tensioner too that could be worn.
 
Hi thanks for the reply just looking for ideas before I start to pull it apart again. Alternator chain rattle- I've read that the tensioner can give up. So that's a possible cause as the noise comes from the right area. Will look into the clutch as that is easier than pulling the engine apart. Really annoying as apart from some gummed up carbs it's been a really nice bike. It's done 30k miles don't know why everything would go at once most annoying.
 
Anything including cars that use a chain tensioner of some sort generally wears all parts concerned with that chain run pretty much the same, and the tensioners and guides often fail way before the chains themselves. It's pretty much a function of the design shortfalls. The chains constantly present new wear surfaces as they are moving but the slippers. guides, and tensioner blades cannot and wear in one spot mainly to fail quicker. When you redo chains you also redo the parts that run against them or commonly a mistake. Cars are the same way but the guide parts are much more beefy than bike ones are, the latter are often very frail parts that can break easily as the bikes are in no way intended to last as long as cars which can go well over 150K miles now and expected to. We pretty much don't expect that of motorcycles and the designers take note of it.
 
I didn't check the cam chain tensioner but I did notice the little tower you press down protruded twice as high as it did with the old one. I don't mind taking engines apart but I do have time constraints and leaving bits lying about for long time periods especially in my shed is not conducive to stress free reassembly. It's trying to isolate the problem then I can decide whether it's time to say goodbye or dig in and sort it out. The conundrum is if I fix it how long or what is the next thing to go wrong. Don't mind in situ repairs many engine out strip downs not so appealing.
 
'It's trying to isolate the problem...'

Why ALL the tensioner parts get changed by mechs who have already found that out. The chain being new quits making noise itself but any part that touches it does not, and worse on most bikes with vulcanized rubber coated surfaces to then wear down to bare steel to then make noise, the rubber may only be a 1/16" thick on the running flats of the guides.

'The conundrum is if I fix it how long or what is the next thing to go wrong.'

Again, for the same reason.............in car repair you change EVERYTHING, or get bit by the noise thing. ALL parts wear equally or at least close. Meaning you change the chain, tensioners, guides, rails, any pulleys involved in the chain run and if more than one chain you have to do it on those the same way. Pretty hard to stop the noise with just one part on those mechanisms. On bike engines with multiple chains it can get expensive real quick.

On chain drives one has to make a judgement, to go all the way or do nothing, the in between commonly results in disappointment.
 
Had a moment to go up the shed. Started it - familiar rattle. Switched the lights on but they didn't immediately come on then they did and the rattle stops. When engaging the clutch the rattle seems to eminate from the same place, the alternator . Any ideas about what might cause the rattle. Given my troubles started with my tacho going hay wire and the battery drying out. I assumed it was reg/rec and replaced it, could it have been an alternator problem if so what and what would cause the rattling. The alternator looks like it spins permanently and i guess being under load dampens the rattling . Thanks
 
I had the same thing, the rivets that hold the gear to the clutch basket were loose, replaced with a good clutch basket and the problem went away!
 
We're talking about a totally different design engine here. Way more than one design DOHC 750 by then (92 model)..........
 
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