I have an ASP .61 2stoke in mine. Needless to say, it has plenty of power, and by all standards is very overpowered I'm sure. I built it several yrs ago(like 10+yrs). I can tell you about the tip-stall too... it happens very easily without the newer concept of the built in wash-out. Mine can be, and is a squirly little thing, likes to ground loop on take off, and will tip-stall if not landed with some power pulling it along. Other then those idiosyncrosies, it's a wild little plane that begs to be turned loose....definately NOT trainer like in the least....so don't let that high wing fool you for a second. Somewhat unique as well too, as you don't see a whole lot of them either. I've only ran across a few other ones in all the years Ive had mine. Good luck.