I started with the 46fx on mine but went to the ys63 and it was a HUGE differance. The fact that I made taller landing gear and and it swings a 13x6 prop adds to the equation but it is a completley differant plane with that setup.

With the 46fx and an 11x5 it was managable but still twitchy and the throws were low. After the switch it calmed down and I could fly it wildly straight up and down. It imediatley made me seem like a better pilot.

Without a doubt the 3 most popular engines for it are ys63, saito72 and irvine 53. Spend the money on the YS because they are a better more powerful engine.