Can you be a little more specific on how the engine quit. Do it warble or bog down before it died on you?
Well, the first time is stopped, I had been flying around for probably 3-4 minutes at 1/4 - 1/2 throttle, then I gunned it to full throttle while climbling slightly. Sounded like it may have loaded-up a little then stopped.
Second time, had been flying around for 2-3 minutes at 3/4-full throttle, then lined the plane up for a high-speed pass. Just as I was about to cross mid-field, the engine just stopped. No bogging or anything. Just stopped while at full throttle and full speed.