I have a Airvista Hobbico made for .40-.43 and I have a .46 in it but I dont believe that could be a problem.

But When the aircraft idles should the plane move on flat concrete surface?

Most planes will if they're fairly light. Once the engine has been run for several flights you'll probably be able to lower the idle setting slightly, but it may not be able to sit still on concrete.

The .46 isn't too much if that's what you're asking.

PS. A lower pitch prop will help too.

Thanks CafeenMan I am currently using a 10x5. but after a few more tanks ill try to lower the idle.

Try a 12-4. 10 x 5 is too small for a .46 on a trainer.

The larger diameter will give you more flywheel action which means you can idle lower. The lower pitch will give less thrust. So you get a double plus. :thumbup: