I know the Chilton book states the valve lash is hydralic but when there is a lack of clearance & compression is leaking past valves, is there a shim that can be replaced? Or do I have to remove the cyl. head, pull valve, cut valve & reinstall to mantain clearance ? Chilton won't say. Our local Dealer is ordering a "factory" manual for me, but until then has anyone tried to fix the clearance on a twin cam motor (1800) without pulling the head ?