My Son was riding his 450f at an MX track yesterday,when the bike locked up after landing off of a jump.It will start,but the transmission is locked solid. I suspect that he may have landed with his foot on the gearshifter lever,since it is bent downwards,and has a crack around the clamp that fits on the shaft. I suppose that the shift fork may be bent? Is there something inside of the clutch case that may have broken that could be fixed w/o splitting the cases? I plan on tearing into it today,and will post updates. Does anyone have a good transmission for sale? The thing is,that I have a good 250f transmission in my garage,too bad it won't work!