After you switch to the YS 63 you will wonder why you did not before. Doing it for tank location is only a bonus. The ys has superior throttle response and fuel consistency. I can hover my 5 LBS OMP all day long at about three clicks above idle. Be sure to use the APC 14 x 4 W. A 12 " will allow the engine to over RPM. Too high of RPM will damage the motor. Real 3D flying does not need a tremendous amount of RPM, you need low end torque and thrust. I can hold my 5 lb omp's nose up at about 3,000 rpm. This is at about 1/8 throttle. You will have 7/8 throttle left to power out of a boo boo. At this throttle the motor is quiet, smooth and easy to handle. A two stoker has to develop more rpm's to gain the same thrust. It will be more jerky. Don't get caught in the RPM and HP game. For real 3D flying you need thrust. With the ys 63 and the 14 x 4 you will have a 2 to 1 thrust to weight ratio. That is the key to good 3D. A two stroke will not deliver that much thrust (low end) on a plane this size.