today i was delivering pizzas my bike, (big red) with a new 66cc RAW kit, and i turned it off, then it backfired! i first thought it was something that blew off of my block or something, but i stop to inspect and everything was there. then at my next stop,it did it again. i finally at the next stop, i took out my earbuds, to hear clearly, and i confirmed it. is this normal?
but i was just curious as to why it is happening. and freewheel, i love M$, but i reccomend if you don't like vista and like mac, wait until october 22nd, for windows 7 to come out. it is suppposed to be the mac killer, and has a dock 
