For me, the 12.25 x 3.75 was the perfect fit for my STOCK 46fx on a somethin extra. That engine is on a canard, and now likes an 11 x 5. But no way is that prop too much, that's what it was defined by. My OS 50 loves it too, though I haven't had time to try many props. Now my SE goes up as fast as it goes horizontal!

Gordon