Can anyone help with a shifting problem,my 1976 xt500 which ran great until it would not go into 2nd gear.If I start the bike up put it into what I believe is 1st gear then try to shift to 2nd gear it does not go in only makes noise if I shift again it goes to 3rd gear then 4th and 5th.Does the cases have to be split or can this be fixed by going into the clutch side? Thank you