New Engine Sound - 79 GS1000

[Guest]

I may already be onto the answer, but looking for some confirmation. I have a 1979 GS1000 with about 50-60k miles on the engine. Recently - only noticed when warmed up and only at idle - it has an light irregular rattle that sounds like it's coming from the top end. I'm guessing either the cam chain tensioner isn't working right, or the cam chain is stretched, or maybe both?

[tom203]

Have you checked the camchain tensioner to make sure it is free to push out? Have you seen/read this link?

http://members.dslextreme.com/users/storagecliff/images/engine_odds-n-ends.html#A06

[Skowinski]

Have you checked the camchain tensioner to make sure it is free to push out? Have you seen/read this link?

http://members.dslextreme.com/users/...-ends.html#A06

Thanks. I haven't yet, but plan to check the tensioner, and measure pins on the camchain also. About to pull the top end off for a valve/guide/seals check anyway. Just was curious if my description of the sound was like others found when these things were not right.

[BadBillyB]

This is a classic example of "camshaft end float".......Billy

[tkent02]

About to pull the top end off for a valve/guide/seals check anyway.

I'd ride it another 100,000 miles or so first. A GS that isn't making noise isn't running.

[tkent02]

Here's the deal, a cam chain adjuster that isn't working the engine will sound like a paint can full of gravel on a paint shaker, it's very noisy. A stretched chain won't make noise, just alters the cam timing a bit, and it won't happen until way past 100,000 miles unless the engine has had a very strange history like racing it with no oil changes ever...

As far as valve guides and seals, how much does it smoke?

[Skowinski]

I will look into the cam end-float issue, thanks.

Smoking is not too bad, but varely visible at times, not at others. It isn't likely to be the cylinders, as I installed a 1085 Wiseco piston kit about 5,000 miles ago. The top end has not been looked at in a very long time though.....