I have a Saito .91 on my VF Edge.... I mounted mine inverted, and I think I'm a little low (fuel tank to high).... 5.25 is on target... I have a 6v nicad just in front of the wing joiner... Remember to mount the throttle servo in front of the wing joiner.... It's a little crowded in that area, but I have had ZERO problems.... It's a great flying model... and pretty tough. I can hover (slow pullout), and torque roll mine.... Saito .91 with a APC 15x4w