I know the CG is 20mm in front of the lower wing and 64mm from the bottom. But my question is why I had to add 9oz to front of the plane to balance it. This is an ARF and the engine is the Magnum 30 which is recommended. 9oz is almost the weight of the engine (engine is 9.6oz). Did you guys had to add this much weight with yours?

Thanks
Barry