I have a sig extra 300xs with a brand new zenoah g45 with a 20x10 prop. I am wondering whether to keep this engine or get another one that would be better for 3d? I know zenoahs are really heavy and my rx battery is near the tail to keep it balanced. Can you recommend any engines, preferably gasoline, that would be better suited for this plane, or should i keep the g45? I want something in the 400-600 dollar price range also. Thanks.

I would keep the g45. Fly it like it is, and then when you're ready to move on, sell the engine and airframe and invest in something else when you move on or move up.