I agree. I had excellent results using APC 11x5 props on the older .40 FP, an older engine that's similar to the .40 LA. This results in excellent climb and reasonable top speed for high wing trainer style aircraft. These engines are like four-strokes and make their best power at lower rpm. Putting a tiny prop on these engines because you think that it is written in stone that an engine has to spin 14,000 to 16,000 rpm just because it's a two stroke leads to the dog reputation of these engines.