My buddy and I both purchased 08 Yz450F’s at the beginning of the summer. After four rides (not including the break in), It felt like the there was an excess amount of compression when trying to kick them over, I never got it started. After taking it to the shop I found the timing chain tensioner failed, jumped time, and bent the valves on both bikes within a few hours of each other. Yamaha and Beaverton Honda the dealership we purchased them from said sorry out of warranty. Kind of a crappy deal considering they had less then 30 hours on them. In addition the bikes were maintained meticously in between those four rides. Has anyone else had this problem?