click click........click

[tkent02]

click click...........click
click click...........click

This sound at idle from a '78 750 we've been working on. Stock engine.
It happens at about as often as the chain goes all the way around the sprockets, something like once per second or so, but we looked and can't see any bad or tight spots on the chain, no kinks. Sound seems to be coming from the head. The sound goes away at higher RPMs, the bike runs fairly well, has good compression.
The tensioner is tensioning fine.
Anyone heard this before?

[TheCafeKid]

bound link? Just cause you cant see it doesnt mean its not there... Try spinning it by hand? Otherwise, if you truely think its motor related, id look into the starter clutch. Doesnt seem to happen as often on these, but ive had one be bad...

[tkent02]

Starter clutch would be every revolution, no?
This is something like once every twenty or so revolutions, has to be the chain, right?
But there are no problems we can see or feel with the chain. It runs smoothly at hand turning RPM, no bent links or anything.

[TheCafeKid]

Starter clutch would be every revolution, no?
This is something like once every twenty or so revolutions, has to be the chain, right?
But there are no problems we can see or feel with the chain. It runs smoothly at hand turning RPM, no bent links or anything.

Wheel bearing? Cam chain? I dunno chief, Id have to hear it for myself...

[tkent02]

Not wheel bearing, it's sitting there idling.

[TheCafeKid]

Not wheel bearing, it's sitting there idling.

then its not the chain either.. clutch? Hell i dunno brother. Maybe the click youre hearing is actually arcing on the head from a bunk plug wire..

[duaneage]

Kinda hard to guess from the info presented. Loose camshaft bearing cap?

[tkent02]

Kinda hard to guess from the info presented. Loose camshaft bearing cap?

Noo, we checked all that obvious stuff.

[Guest]

Cam chain tensioner/guide or chain itself. I'd say broken rear guide binding the chain once and a while.

[tkent02]

Two different tensioners, same noise.
Dunno about the rear guide.

[Don-lo]

A piece of debris (aluminum) stuck in the big gear or the clutch gear will click noticeably.

[Danjal]

You have a parts gremlin loose in your motor. Better get him out before be breaks everything one piece at a time.