I was helping someone with a XR600 rebuild. The parts are about to be ordered. The cam chain and tensioner are on the list. The question he put to me is "do the sprockets need to be replaced?" I had never really thought of it. For a final drive chain the sprockets are always replaced with the chain, does this follow for the cam chain? This is a very high time engine. It made me wonder so I'm asking here. When I replaced my cam chain I didn't even think about it. The cam sprocket looked good, but I don't even remember checking the crank end sprocket.