You have to get a second engine b/c you have to keep that trainer going. You are never too good to stop learning how to fly. There is always something new you can do with a plane, especially when you finish training. You know the limits of that trainer and now would be the time to stretch those limitations and do new things in the air instead of boring holes in the sky. I have a few engines sitting and waiting to go into a new plane. I have a 40 LA Blue, 46 Magnum, and a 0S 40 waiting for that next plane I steal at a swap meet or get from someone at the field. I don't think you can have enough engines b/c you can never have enough airplanes. IMHO