On my LA 40s , Fp 40s and all the others I use the APC 11 X 4 prop for the thrust. We are on grass. One thing not mentioned is to have the airplane sitting so that the wing is at a positive angle. We have had newbies, and not-so-newbies, with BB 45s and 46s on their trainers who can't get off the ground when the wing is at a negative angle.

I do not have that particular trainer, but do have 2 Right Flyer 40s, and an Eagle 63. All take off just fine with my bushing, airbleed carb .40 engines.

Ken Erickson