I am back into my 08 YZ450 after it ingested a ton of dust at the last 2 harescrambles. I'm already in it for a new cylinder, piston, rings and more than likely valves. The reason I am asking about the crank is due to my guidance from the local Yamaha "stealership". With the dust ingestion came running hot and the kickstart side intake valve hitting the piston ONCE! I attribute the valve smacking the piston to piston/cylinder wear and/or a stuck intake valve. My thinking is that when the engine ran hot, the valve springs weakened allowing that valve to "float". The cam journals did not seize, or even begin to seize. SO, for the direct question...How do i check the crank and what is the spec that i'm checking against? I'd love to throw another $1500 at it for a complete rebuild, but it's just not in the cards this go round. This is an OEM crank that was replaced last winter...9-10 races on the entirely new rebuild and now this. What do the wise have?