I just finished my first timing chain job on my 1975 R90/6 with a double row chain. I wanted to type it up while all that info is still fresh in my mind. I am a novice mechanic, but I got plenty of help from List Gurus, local Airheads and a local shop. I did all the hands on work myself. Here is what I learned . . .

YOU CAN DO IT. You will want to replace everything. Don't do a rinky dink job that will need to be redone sooner rather than later. Replace the chain $35, crankshaft nose bearing $10 and sprocket $65. Also replace the tensioner $10 and spring $2, and all gaskets and seals $17. These are 2003 prices. I got everything from Motobins and Eurotech. I found that the most worn piece was the crankshaft sprocket. The chain and bearing actually do not wear that much, but that sprocket is half the size of the cam sprocket and made of some soft stuff. The teeth get narrow and pointy. The gap between the teeth gets really wide as the sprocket wears. That's where most of the slop in the old chain comes from.

REMOVING THE OLD CHAIN . . . First remove the tensioner and spring. Before you cut the endless chain installed at the factory, make sure that somebody else has not done this before you. Look for a master link. If you need to cut, there are two