Could a loose cam chain bend a valve?

[jonathan_whitwell]

I had the cam chain tensioner set up wrong on my 82 gs750, and it got really loose and loud so I pulled it over and took it home in a truck. I re-installed the tensioner correctly, but now there's a really bad slapping noise that gets worse with more rpm's. It sounds normal at idle, but once I give it just a little throttle it gets way worse. I've checked to make sure the cams didn't skip a tooth, and that they're synced up with the crank. The only other thing I could think of is that I might have bent a valve. Does anyone know how prone these engines are to bending valves by running it with the cam chain too loose? Is there any way to check for bent valves without removing the cylinder head? Is there anything ELSE that could be making this kind of noise?

[earlfor]

I've heard of people incorrectly installing the cam chain one tooth off and not understanding why the bike runs so badly. :-) I've never heard of a bent valve resulting from it though. My best guess is a slack tensioner would not cause a bent valve. The cam chain is pulled by the crankshaft sprocket, so the front side is always in tension when the engine is running. The tensioner is on the back side to take up slack in the return run of the chain.

Earl

[earlfor]

I would remove the spark plugs, and remove the right engine case cover. Take a 19mm wrench and slowly rotate the engine clockwise by hand. If a valve it hitting, you will be able to feel it unmistakably.

Earl

[Nessism]

If a valve is bent the lash clearance will increase since the valve will not close properly. Compression will be off as well.