Ok, Ok, Ok...Ive had the shop check the valves on my lightly used 2004 YZ450, and then I checked them, and they are all within spec. Yet I still have a anoying ticking that isn't so subtle. It isn't like you can barely hear it, and it bothers me. When you are just idleing around it sounds like lifters in a car motor that lost its oil-kind of like a tappet sound. When I get on the throttle and hammer it for a while it goes away...mostly. HELP! If it isn't the valves, what else could it be? I really don't want to implode the engine or pay to have to dismantle the whole thing. Any other ideas? I ws wondering if a valve could be off but still be in spec...?