747,

The 49" WS Rascal is designed for a .049 to .07 glow fuel motor. A .40 sized motor in it would be grossly overpowered. However I don't find anything wrong with using the Rascal as a trainer with the proper sized engine. I've been training my brother-in-law on a 40 sized Rascal and we've been having a ball.

If you want, you could use a .40LA bushing motor in a SIG LT-25 great 4 channel trainer. It's wing span is 63"

John