sportrider,
You're right about 25% to 30%. The 30% or 33% would be better, if you haven't been flying very long. True center of gravity is perfect at 37% of the wing chord. The full size Ceesna 206 the center of gravity is 12%, but don't get too slow. I would set the c of g at 30% fly it. Make sure you have plenty of elevator authority. I have a 1/4 scale Sig clipped wing Cub and have my c of g set at 37% and it flyies beautifully.
Good luck,
Darrolair