I bought the 450 xc about three weeks ago and have not ridden it yet, Because of the weather and because I wanted my brother to look over it. Good thing he did, it only had about a cup of radiator fluid. The problem that I'm having is that when the quad is at idle and you rev it up, it makes a bad crackle sound when you let off the throttle and sometimes will shoot out a pretty little flame. We dont think that is correct... Do you guys think it needs to be re-jetted or what other problem could it be.. Thanks for all your help.