83 CB1100F Engine Noise

[mrmach5]

My 1100 F , 14k miles at some point developed some engine noise. Not a clutch noise, more left or center, kind of a light knock.
Synced the carbs and made some improvement. Also adjusted the cam chain at the front and back .Then I remembered hearing that it was common for the three bolts holding the starter clutch together to come loose ,,,,,,, and sure enough all three loose . So I decided to replace the whole assembly with the far superior Yamaha Y6 starter clutch, and it works flawlessly . So the bike is running beautifully , however I still hear this slight knock.
So its going up on the lift, and I'll start by removing the valve cover to see if anything reveals itself and drop the oil pan to see if there are any clues there. Trying to think of things that could create that sound (other than a rod knock which although not impossible but probably rare in a low miles bike) ?

 

[Oscar Meyer]

This might sound odd but check to make sure you don't have an exhaust leak where the header pipes connect to the cylinder heads.

 

[mrmach5]

Valves all within spec, but found quite a bit of slack in the cam chain, probably what Ive been hearing. I'll attempt to adjust the tensioner but something tells me it may be futile. Guess next is remove pan to see how much tensioner material is in it. Not sure if replacing the tensioner is possible with the engine in the frame.