Topic: Cam Chain Adjustment Question

[Dr. Frankenstein]

I am happier than a clam at high tide that I finally got my '72 CB500 Four up and running, but I have a question about the cam chain - what does the UPPER cam bolt do?? I've adjusted the cam chain according to the manual with the lower adjuster, but when I start the bike there is a rapid 'ticking' noise, and I think it's because of the upper adjuster possibly making it too tight/loose?  My valves are set perfectly at .05 and .08, so I don't think it's those.

When I had the bike apart and was wrestling with the cam chain sprocket, I noticed that when I turned that bolt IN/tightened it, it pulled the tensioner closer to the wall of the block; and conversely when I turned it out, it of course pushed the tensioner away from the block/towards the cam chain sprocket.

I haven't tried to adjust it yet - (it's 7:00am and these are the kind of things that wake me up) - but I think the ticking noise just has something to do with the adjuster(s), I'm just not sure if it's that or something more sinister...

[bryanj]

The upper bolt is not an adjuster but just a retaining bolt and should be done up tight

[HondaMan]

The Tensioner Adjuster is a spring-loaded gizmo on the rear tensioner assembly. The lower stud with the slotted screw head is the tensioner lock and adjuster and should NOT be turned: just wiggled back & forth a little if it was stuck. Wiggling the screw can release a stuck tensioner spring sometimes, if needed. Since yours was just apart, it's highly likely to NOT be needed to release it.

Here's how I do them: engine off, I remove the #4 intake valve cap and slowly kick the engine over until it is just starting to tighten on the valve. (If you are looking at the spark advancer behind the points, there is a 'corner' on the advancer's backplate: the timing indicator will be pointing at that 'corner' right then). Right there, I release the nut of the Tensioner's mounting, and the built-in spring will take up the cam chain's slack. Then just snug that nut back down and put the cap back on.