Had a YS 91 AC in mine, balanced right on the specs. I used BB coreless servos retired from pattern planes when I put in digitals. Be careful if flying with the 3D rates. Was flying mine Sat, doing snaps and spins. Came down out of a short dive toward the ground, was going to pull up into a hover, and the plane snapped before I knew what had happened. Didn't get to fly it much, but what little bit I flew it, it was awesome. The 91 had plenty of power, would pull up out of a hover like a rocket with an APC 15x6.