An easy way to check the plane is to take a real small screw eyelet and screw it into the center of the wing in the CG area and lift up the whole plane (minus any fuel). If it tips to the side you can add some self sticking wheel weights (like noted in the previous post) to the wing tip or where ever needed. You can get the small eyelets at craft stores. I used this technique on my U Stick and even left the eyelet in the wing. Works great.