I had to add 8 oz. to get mine to about 4.5" cg. Right now I've got an OS 46 LA with a 12.25 x 3.75. It does o.k. but I just ordered a K&B .48 for it, and plan to move the battery in with the tank when I swap engines. Hopefully that should make it a little more exciting.
My wing bolt also feels a bit off, especially when I tighten it down. I'm going to replace it today on the way out to the club.

This is my favorite plane, now I just need to learn some of these 3D moves.