so I bought a used 2010 450 during the fall. I threw it in the shed during snowmobiling season. Well i decided to take it out and take it apart and rebuild it fresh for this coming season. I pull the head to find what looks like all 4 valves hit the piston, but it looks like they only hit just once. Did the previous owner not set the timing right before trying to start it? I would think if they hit while it was running, there would be more damage. bike ran fine when I tore it down. I put water in all of the ports to see if the valves leaked at all, but the valves didnt leak, so I dont think they are bent. Another mystery, I see its a vertex piston, and it has a cylinder works cylinder. It appears to me that the companies are linked in some way. Im wondering if he had a bad issue and lost the factory piston and cylinder. Do some people order a new cylinder while they are doing a piston? I never have. Just trying to clear up a few mysteries about this bike. I guess one plus, the valves were in spec.