If you don't want to invest in a new, more powerful and HEAVIER engine, try a MACS pipe on that good ole reliable FP.40. I ran one on a Magic, with hi-power mid sized servos. That engine only weighs about 9.5 ounces, but the heavy, stock muffler, robs power and adds weight. with the MACS, short pipe, I could swing an APC 12.25 X3.75, 12X4 and 11.5X4. My plane came in under 3.5 pounds, with wing loading around 11-12 ounces per square foot. I kept moving my CG back until the flying CG test past, nearly same straight and level up side down as right side up. Makes 3-D allot easier. Also make sure you are laterally balanced. Great fun fly and starting 3D, just close coupled making hovers hard. Good luck