Tail draggers usually have 2 degrees of right in them to compensate for engine torque. You could put in 2 degrees of down and give it a try. The CG effects the plane by making it go up and down. Nose heavy will make it fall and tail heavy will make it climb, but tail heavy will also usually effect your flight controls as well. Balance the plane again and if it is right on, then put a couple of washers on the top motor mount screws and see if that helps. Good Luck, Dave