Cam bushes

Hi,

I'm getting ready to get my 1973 850 back on the road. I've noticed that the cam bush on the timing side has a slight groove in it, in the axial direction. It feels to me like it's from the key rubbing on the bush when splitting the cases. I know the key was in the cam and it went through the bush when I was separating the cases.

I was thinking the cam would stay with the timing side and so I didn't pop the key out before separating the cases. Like I said, I can feel and see a small groove. The edges aren't sharp, no burrs or anything like that. It feels much less significant than the oil hole that's in the cam bush. Do you think it's safe to run it like that? With a new bush, would I need to get it line bored?

-Eric

I looked at this bush some more this morning. The key seems to clear it easily if I insert the cam. It's dark, so it must have been that way for a while:

https://onedrive.live.com/?cid=6d60bfeb ... LIXjtFTu4g

Hi Eric
If there is minimal movement of the cam in the bush and the bush is not obviously worn then I would be inclined to reuse it. If you think you may struggle to trust the bush for longevity then you will need to replace it.
Ta.

Eric, I wouldn't worry about the 'dark groove' as long as you don't have any noticable movement of the cam in the bush. If you replace the bush(es) you should get them line bored :!:

My 1st Combat was 1st vender shop maintained for hot rod demo sales bike then 1st & 2nd owners let same same keep in going so when I opened just for leaks found the cam bushes spiral oil grooved to continued the pactice and llate came across mention of this to help cam spin nice longer. I also opened oil drain holes and textured case wall to tend to drain into the holes.

I have a scrolled cam and plain bushes. I understand that scrolled bushes require a plain camshafts.

ewgoforth said:

I have a scrolled cam and plain bushes. I understand that scrolled bushes require a plain camshafts.

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Not so. I have a scrolled cam and scrolled bushes.

I think the main thing is at least one surface be grooved and glad to know no problemo if both are grooved which I'd wondered about. On the DS its considered an old school upgrade to use the dual bushes to gain an oil resivior between them. If cam out it'd be a good time to cryo temper it and lifters and maybe dry friction coat too.