I've seen one fly with a YS 63 locally, After all is said and done, He wishs he had stuck with the 46. Seeing as he has added 14 ounces of lead in the tail, and the extra ounces in the engine, his plane now weighs in at close to 5 pounds, and flies for 7 minutes on the supplied tank. His 3D, and slow speed/harrier flight is suffering.
Now, My 3.3 lb Magic on the other hand, will pull vertical out of a hover like a rocket with the 46FX and 11x4 Zinger. Except for vertical snaps, I fly at quarter to half throttle. It hovers at quarter throttle, and I fly for 15 minutes on 8 ounces of fuel. With this kind of unlimited performance, why spend another $130 on a big, heavy 4 stroke that would cause you to have to add lead to the tail, and supply more fuel?

Dont get me wrong, I LOVE YS engines, I have three of them in other planes, but in a plane like this, I dont see the need at all!