Motorcycle Repair: Cam chain tensioner 76 CB750A, honda cb750a, crankshaft rotation

Question
Hey, I have a 1976 Honda CB750A that I got recently.  I adjusted the cam chain tension as per the user manual (ran the engine at idle, loosened the lock-nut and bolt and retightened them) and as soon as I loosened the bolt I heard the valves begin to tap - not major tapping but a sound that was not there before.  I tighted the bolt and lock nut and the tapping persists.  I was just wondering if the sound was normal or cause for concern

Answer
It is better to do the camchain tensioner adjustment with the motor off. It is too easy to tighten down the bolt when the plunger is on the outbound motion, instead of the inbound direction.

If you put a wrench on the end of the crankshaft, you can turn it back and forth while watching an open valve through a handy open valve cover. If the valve action doesn't follow crankshaft rotation in either direction, then the camchain tension is not set properly.

Loosen the lock bolt, put a small rod (allen wrench will do) inside the end of the recess where the end of the tensioner plunger is located. If the end extends outside of the tensioner housing, just watch it as you turn the engine over by hand until it goes in as far as it can, on its own. THEN you can tighten down the lock bolt and the noise will be gone.

More tips at www.sohc4.net

Bill Silver