This is not an easy plane to balance. Mine would sit on the balancing stand and if you let the tail down a little it would fall back until the tail touched the table and if you pushed the nose past horizontal it would fall forward off the balancing stand. There is a very small distance from completely horizontal on the balancing stand and the plane will tilt one way are the other. If you will work from holding the plane on the balancing stand straight and level and see which way it wants to go then add a little weight and go back to holding it level and try again. You might be surprised how little it may take to balance it. I just worked on it until I could get it to remain level without holding it, but it would still go way off either way if you lightly pushed on the nose or tail. It flies perfect. I have an OS 46FX with the battery pushed under the servo tray all the way against the servos and the receiver pushed against the battery mine took 1/4 oz to balance, mine is the arf built as per the instructions. Hope this helps.
fossil