Now that you mention it jeeper I'm using a heavy prop nut too. I flew it for awhile with the stock setup but later put the battery under the tank. I can't see much difference. Still have the weight on the cheeks. It balances at 4.5 in. I've come to like the wind. It makes for extremely slow landings. The plane will almost stand still if I pull back on the throttle and fly into the wind. Almost like an electric model. I don't have rudder and elevator control down too well, makes trying to hover tuff. I keep trying though.