A bad glow plug will do that too when you pull the ignitor off. If it runs now then you should be fine. You will have to lean it out as you break it in because they are set rich from the factory and as you break it in it will seem to run rough and want to stall with alot of white smoke coming out of the pipe which is normal because the richer it is the more it will smoke especially with the traxxas fuel. You really should only have to lean out the high speed to get it running pretty good and fine tune it later after the break in.