I have a 4 Star 40 with a 46FX on the front end. It (the airplane) is nearing retirement as it is getting quite worn and is need of recovering (at least!). A 46FX is plenty of power for it.... you can fly around all day at half throttle or less. I think anything too much larger might be asking for trouble... but hey, that's just my opinion.

If I can make one suggestion,...do a search or two on the forum for possible mods/changes/enhancements/improvements before you start working. The mods I made were to get a Sullivan tail wheel mount (instead of the stock unit), some tri stock on the vertical stab and dual aileron servos. The one mod I wish I'd made was to replace the landing gear mounting nuts with larger nuts and use nylon bolts to hold the gear on.

Have fun with it, it's a nice flying airplane!