RE: Engine for 4*
HI Chemie,
The plane was an ARF in Red. It came in 100% red. I mean EVERY corner of it was just plain red. They give you sheel of decals (the long starts that you see on top and side) the problem with this is the decals are a light white see through and are for show on the ground only. In the air can't see them. I flew the first day with just the stars on the top and the side and I had such a hard time with it because I could not figure out if the plane was up, down, left right. I Safely landed and went home. Bought a roll of white ultracote and made the strips and stars under the wing. It's helped a lot with the visibility. I HIGHLY advice that you add some pattern to the bottom (stripes, Checkers, of whatever that fancies you).
46 size engine is perfect for this plane.
As far as uses for 55ax, they exist, there are planes that can benefit from the extra power, 4* just isn't one of them. People that do kit builds will add different things in their planes which may make it heavier and they would have the option of using 55ax. Other scaled 40 size planes could also benefit from a 55ax such as the decathlon.