Cam Chain Tensioner

[GMSKEE]

Is there anything I need to be careful of when removing the CCT. I have a weird noise coming from the engine and normally happens in 3-4 second intravals and about 1-2 seconds in duration and goes away when I speed up. It only sounds when Im stopped or in idle. I belive its my CCT. Do I need to open up the top end for any reason or can I remove the CCT and inspect. Any help would be appreciate.

[hampshirehog]

The noise at idle is usually the clutch. Are you sure it's not coming from there?

[GMSKEE]

It could be but its really hard to tell. I tried to do some research and I dound that it might be cam chain walk, or something like that, it kind of sounds like the knuckles on the joins of the chain rubbing on the inside making that noise. Do you know the noise Im talking about?

[Steve]

If it is an intermittent knocking that is happening at the intervals you are describing, it sounds like "cam walk".

Does it go away by the time you get to about 1500 rpm?

If so, that's what it is. Evidently, some engines were a little more prone than others, but the thrust surface that keeps the cam centered wears away a bit, allowing the cam to move sideways a few thousandths of an inch (hundredths of a millimeter). When you spin the engine faster, there is more tension on the cam chain pulling the cam to center, so the noise goes away. Chances are that your tensioner is still working just fine.

.

[GMSKEE]

Hey Steve,

it is exactly that, goes away at about 1500 rpm. Is there anything I can do about that or should I not worry about it. The bike is a 78 I expect noises but it sounds discerning

[Steve]

Discerning or disconcerting?

Either way, don't worry about it.

There was a fix that BassCliff has posted on his website, if you want to see what's involved in geting it quiet again.
My wife's bike made that noise when we got it 5 years ago, and have put on about 20,000 miles on it since then.
It still makes the noise, hasn't gotten any better, hasn't gotten any worse.

.

[Nessism]

It won’t hurt to check the tensioner, and possibly change the seals while you are at it. Bwinger did a nice write up on how to service the tensioner. You might want to search it out - I suspect Basscliff has a link. I recommend setting the engine at 1-4 T before removing the tensioner and be careful to not turn the engine after the tensioner is out. After you reinstall the tensioner, double check the cam timing to be sure nothing jumped.

[GMSKEE]

Disconcerning! but you knew what I meant. Thank you for your help, I really appreciate it. I kick myself in the ass though, cause I took my bike off the road about a month too early so that I wouldnt do any more damage. Oh well lol. Thanks again.

[GMSKEE]

Thanks Nessim for your input too. I will check the tensioner too.

[mike_of_bbg]

I had noise coming from my tensioner, but it was more of a rattle that appeared at ~2kRPM and went away ~4.5k. While it was happening I could see the tensioner knob rattling (obviously sitting next to the bike and hitting the throttle). I rebuilt the CCT but probably could have gotten away with just adding a turn of tension to the outer knob spring.