I have a 2003 Raptor that runs perfect at idle and every gear running top speed. The problem is that when I put the bike in reverse (Clutch still all the way in), the engine backfires, sputters and dies. The ONLY modifications are that I took off the Emergency brake assembly. That left the clutch and e-brake sensor switches unplugged. Any ideas?

 

raptors have a reverse rev limiter, thats why it does that. You can unplug a wire by your shifter and ground it, that will get rid of it. Do a search on reverse limiter or something like that, tons of info on that is available.