A friend of mine bought a LT-40 and learning to fly. I put a OS 40 LA on it.... It is a very reliable engine and why spend the extra money for a 46 FX when it's for a trainer that is meant to fly slow? I have a 46 FX on a fun fly plane and I think that it would just be more power than needed and for people starting out usually they are trying to save the money anyway to buy all that they need to get started.... But I guess you can get the 46 FX so that when you are ready for another plane you got a powerful motor. That is my idea.. Anyway, good luck and get flying !!