RE: Super Cub LP wont balance
Are you testing the COG with battery in or out?
You should be checking the COG with the battery in the plane.
If it is tail heavy, move the battery forward and recheck, repeat process until the plane is a little nose heavy. The plane will fly best when it is a little nose heavy. If you can't get the plane to balance on the COG spot by moving the battery forward, then you will need to add some weight to the nose.