My 2003 Wr 450 F is jumping out of gear. I had problems with no 3rd gear, I pulled the motor out split it apart, took the transmission out and noticed the 3rd gear shift fork was worn and slightly bend. I put a new clutch in it, new shift fork and all new seals and gaskets, put it all back together and now I get 1st gear but I need to hold the shift lever down with my toe for it to stay in gear, if I take my toe of the gear lever it jumps out of gear. Shift through the rest of the gears and theres nothing. Anyone have any ideas what the problem may be. I think there is only one way to mesh the shift cam, shift forks and gears together to get it all to fit back in the housing. Is it possible I may have put a shift fork in backwards or something. Any tips on this would greatly be appreciated.