I've got one with a O.S. 40 LA to save weight and run a 10X5 and it will just about hover. When I run an 11X4 it will hover and pull out of it. The only problem running the 11 is when I land the landing gear flexes just enough to smack the prop. I could use bigger wheels but I like having the wheel pants on it. I don't know how that guy is running a .52. That would use a bigger prop and add a lot more weight than what Im running. The plane DEFINITELY isn't a floater but it does fly well for me inverted. With these small planes you want to run as light as possible. You could use an O.S. 46 LA which is about the same weight as the 40 but with 2/10's of a horsepower more. I've flown a few so anymore questions, just ask