Engine clink

[tom203]

Hey, I'm grasping at straws here! I'd pull valve cover and spark plugs-then rotate engine slowing and look for something odd on camchain .

[jeffgs]

Does it have a slight miss or a shake when it does it? Vacuum gauge?

Ok you said you heard it in the exhaust pipe itself, is this correct?

[NvMessner]

No. The clink was the loudest on the right exhaust valve...area

[NvMessner]

Alright so...I pulled the valve cove and checked everything best I could. @ tom203- i checked out the tach drive, trippy little thing, and all looked good. I spun it several times and couldnt see anything that stuck out or looked wrong. I checked clearances again and discovered that all my clearances are over by .02mm. Spec is .03-.08. mine are at .10-.13, but i'm not sure that is bad enough to cause any clinking. i could be wrong. Also i noticed, while cranking it over, that there is a spot or two when rotating that it spins on its own. That make sense? So im rotating the engine by hand and at a certain spot it not only gets super easy but spins on its own. Wouldn't that be a compression issue? my compression was 140 and 150...

[tom203]

Easy spin spot is likely from crankshaft balancer and/or valve springs as you rotate. Those clearances should not cause this click , but best to reduce them. (I run mine at .0015 inch to .004 inch max). Make sure buckets turn freely in head when lobs are off them

[NvMessner]

I was talkin to buddy at work and he mentioned lifters. Said he had a similar sound on his old harley.

[jsandidge]

I was talkin to buddy at work and he mentioned lifters. Said he had a similar sound on his old harley.

These engines have overhead cams, so there are no lifters or pushrods.

[NvMessner]

Ha. Yes.....idiot.... Only other thought is a valve clinking

[NvMessner]

I got the bike back together and fired it up. After it got warm the clink started again. I went out and got a stethoscope. After pokin around for a bit I notices the clink was loudest at the tach drive gizmo....which looked fine from the inside....

[tom203]

Extract tach drive carefully, plug hole with something somehow, and see if clink is gone.

[NvMessner]

I got the tach drive out. Still Clinking. Decided to just ride it and keep an eye on it

[tom203]

That's about all you can do now- hopefully it goes away. What kind/weight oil do you use?

[tkent02]

One two 750s we have heard a click like you describe. Kind of a double click, like a bad chain link going around the two sprockets. Looked inside, could find nothing wrong.
One of the engines broke a cam chain at high RPM not too long afterwards, although it was running way too hot with almost no oil in the engine at the time.
Not sure if the click had anything to do with it.

[Mekanix]

That is definitely cam walk !
The exhaust cam is walking side to side every time it pushes on the valves.

Thats why you hear cla clunk......cla-clunk......
I've had a valve cover off and watched this happening.
When one lobe pushes down on the shim and bucket the pushes the cam to the opposite side and when the next nobe comes down that pushes it the other way.
The rest of the time the lobes are not touching the buckets you hear no noise.


Now. For solutions:
1 replace the buckets and shims with new. Rocking buckets will do this kind of t hing.
2 use a cam spacer shim from a gs500 to shim the cam so thay there isnt enough movement to make it walk.
3 replace the cam with one that fits the head better.

My gs500 made this noise all the time at idle untill I swapped cams with one that had a shim with it.
Also you could just leave the rubber half moon piece out of the head on the exhaust cam and watch the cam jump side to side. Also you could push the cam in the middle and stop it from making noise.

[tkent02]

If it was cam walk why would it be so rhythmic, exactly one double click every twenty or so revolutions every time?
I'm no doctor, but it sounds like something going around with the cam chain to me.

Should be easy enough to prove by pushing on the end of each cam as it idles.

What is this cam spacer of which you speak?