i went trail riding yesterday put 60 + miles on it with no problems. got up today to do some hillclimbing at bullgap. after about five trips up the hill with no problem on one pass i started in first and shifted into second and that was it . stalled out.. it starts back up but wont go when you let the clutch out.it tries to go but its like its in the wrong gear and you cant put it in nutrel.the shifter moves into each gear like it should but allways seems to be in the same gear. any ideas. is it time for a rebuild?thanks for the help.