Yep, I'd tackle the prop issue. Use a Tornado 5X3 or 5.5X3 and let it scream. One thing I think has not been mentioned is to remove all but one of the copper shims, or gaskets under the glow head. Sometimes that makes it harder to start the engine, but it will increase the compression a little bit, and that may help. Check the C.G. also: you don't want a tail heavy airplane. Good luck!