bhole is correct. I don't remember where the CG is supposed to be on a 4*, but not all planes use the Spar as a balance point.

Second: Even if that IS the correct CG point, remember that it is only a reference point. Now that you have flown the plane, and you KNOW it's tail heavy, Shift some weight forward, or add nose weight. Keep making slight changes until the plane flies the way you want it to.