I have a nitro trainer running on a OS Max FP .40. Before one of my flights last week, I "floored it" from idle and the engine just quit. I made the mistake of restarting it and just flying anyways. It happened again when I was still below 1 dumb high, and facing the opposite direction of the runway. I escaped with little damage though. Today, I went flying again. I never had this problem. The engine seemed to quickly accelerate from idle. The thing is, once flying the engine seemed to be making a noise like it wasn't running properly. It sounded rough-ish. I tried adjusting the idle, but just realized I had no idea what I was doing. Is this the problem or is it something else. Could the prop be out of balace? The engine seemed to vibrate a lot. Is this normal? I also had trouble starting it the first time.

Any help would be appreciated!<br type="_moz" />