I have to agree with Dick on this. It's as much related to fin, side area and dihedral as CG.

I was trying to help out a newbie that had an ARF Piper Cub. But it was a Piper Cub with a devil complex. I've never flown a model that was so prone to stalling and spinning. Checks showed no bad warps, decent weight to wing area for a moderate loading and a decent CG position. The second time they brought it out it even had some washout. Nothing helped. Even from level or only slightly climbing flight it would hiccup and snap roll into a very hard to recover spin. It eventually bought the farm as you can well imagine and the father and son were looking at the bits with an eye to rebuilding. I recomended they burn it instead and move on to a model that could actually fly. They did and never looked back.