I have a Rx Warrior that I run on the asphalt. I took the stock handle bars and controls off from it and replaced them with a set of drag bars and 3' risers. Kept the stock brake set up but replaced the throttle with one from Wahls. Now the sled will only idle. when I hit the gas it sounds like there is a rev limiter on it, will not rev up. Back fires just a little Any ideas?