If this is the Great planes arf then it needs alot of power. Go for the 60 fx or similar, a 46 wont cut it. You also must be sure the wing hold down is corrected, as some had extra play if built as suggested in the original plans. I have some old reviews if you need them. This plane (the gp 231ex) for me is not a good flyer. It is heavy and seems to snap easily. Some have said a change in wing incidence may help, I dont know. I know I dont fly mine anymore after 4 to 5 rebuilds after snaps on landing.If its not the GP cap 231 ex then I'm all wet on all this..
Cuda