Motorcycle Repair: CB77 cam ahain

Question
Bill
I recently had new valves and guides installed in the head of my 1965 CB77. After reinstalling the head I had difficulties reconnecting the cam chain. On the first few attempts the chain connected to the cam sprocket one link short. I took off the cylinders and started again from the crank shaft sprocket being careful to attach the chain correctly to the crank shaft sprocket. This time the chain attached correctly to the cam sprocket and the master link fit easily. But, now the cam chain is extremely tight and the chain tensioner was very difficult to install. What am I doing wrong or what are some solutions. I should add that I turned the motor over several time and found no tight spots in the rotation.
Thank you.

Answer
Bill, When you reassemble the top end of the engine with new gaskets, guide roller and camchain it raises the stack height temporarily until the gaskets compress and the parts all settle down a bit.

When this happens, I put a couple of sockets on top of the studs as spacers and use nuts to help compress the top end parts temporarily while stringing up the camchain. Once the camchain is connected and everything is completed with the head, release the nuts/spacers and install the top cover gaskets, breather plate (holes on the bottom) and the cylinder head cover. Torque all the nuts in a criss-cross pattern to 15 ft lbs. Go over the pattern several times and then recheck them again in a half hour.

Look carefully inside the camchain tensioner hole to be sure that the camchain is riding on the center of the guide roller. The tensioner roller should self-center as you install it, but go slowly as you pull the bolts down evenly. If the motor turns over smoothly, then you should be okay. As it runs in the chain will loosen, the gaskets compress a bit more and the pressure on the camchain should even out.

I have seen aftermarket gaskets that were a bit thicker than OEMs, which can aggravate the problem. Sometimes there are a few high spots that develop on the cylinder head gasket surface and top of the cylinder block that need to be planed down, as well.

Bill Silver