My 01 ES foreman will not shift up or down while riding. It doesnt do it all the time but at least two or three times while on a ride. Switch the engine off at it goes back to workn for a little while. Also my mph gauge was reading all sorts of speed going from 0 to 99 to 50 and so on but it quit for now. Anyone with any ideas on why these problems occur. THANKS ALOT!