I have a 2005 Sportsman 500 HO and as I drive froward in high it will show on my display that it will go down from H to L,N and R causing it to backfire. I talked to my dealer about this problem and he told me it was the rotary shifter switch. I instaled a new one but still have the same prolem.. Any information to help with this would be great.

welcome to the forum. try checking all the connection for corrsion or bad connections and put dielectric grease on them before reconnection to prevent corroding. i would have thought the tranny switch as well. make sure there aren't any chaffed wires in the loop that might be grounding it out. i would guess the bike is back firing when it shows reverse on the read out because the reverse limiter is kicking in.

Your display it just screwy,the Tranny is not actually shifting gears for real is it?

WOW thats a bad NEW design, even if your display wants to do its own crazy thing, the reverse limiter should be activated only if the tranny is shifted in reverse "for real" by a switch at the tranny not a display sensor getting fooled by a display because its brain box is taking a trip.