I have two da-50's one is a year old in my 27% aeroworks ultimate 20-30 flights and is just awesome. The other is new with only a tank or two on a test stand for the initial break in / engine tuning and have had no problems. I would not worry about these engines the number on my second engine is something like 2450. Thants alot of engines with relativly few problems. DA will always take care of you if anything goes wrong. Break it in properly and give it ample cooling and it will run forever