ok this may sound weird but here goes . a couple of times now when ive come into a tight corner or the like too hot i've stalled the bike.it's usually not a big deal as it usually fires right back up as a i release the clutch. but on a few occasions it didn't fire. when i go to kick it over the kick starter is locked the first time it happened i freaked. but i rocked the bike back and forth a little and that seems to do the trick. i'm wondering is this just the piston getting caught if you will on the compression stroke and therefore making it fel as if it is locked. other than that the bike is as solid as any bike i have ever ridden. quite simply the best four stroke 450 out of the box period . grayracer if you see this thread your comment would be highly appreciated thanks.