The Tower Hobbies .46 engine included with the Tower Trainer .40 Mk II RTF package is a very powerful, good running 2-stroke engine. They're not as consistently built as some of the more well-known engines on the market (O.S. or Thunder Tiger, to name a couple). Many folks report nothing but good luck and smooth running with their Tower Hobbies brand engines while some folks have trouble getting them tuned in and running smoothly.

I have a Tower Trainer .40 Mk II ARF that I am flying with an O.S. .46 FX engine. I think it's a very good value for a high quality trainer. I would power mine with an O.S. .40 or .46 LA or a Thunder Tiger GP-42 if given the chance to start over. My Tower Hobbies Trainer .40 Mk II is a bit nose heavy with the ball bearing .46 on it, even with the flight pack battery clear back in the tail behind the servo tray. A lighter weight engine would have balanced the plane better while still providing loads of power.

The Tower Trainer .40 Mk II ARF is a very lightweight trainer airframe and should fly well with the O.S. .40 LA.