...mm is hard to say, Joe an engine flame out is one of the hardest think to figure out.
Once upon a time I had all the good stuff installed on my airplane to monitor temperature and rpms (I had an eagletree data logger), even having those parameters recorded I could not figure out what did cause the flame out on my BME110.
Don't feel bad, just about all the engines I have opperated have flamed out on me, for the 50% of the events I think I know what happened the other 50% is a total mistery to me.

Engine cooling? I know that the head cylinders is fully exposed and that may account for a good air flow; however some summer days in Wisconsin can get really warm as far I recall.