I think you should switch to an APC 15X8 and see if that helps. I think you'll still be a little disappointed with the power output since you won't be able to power out of a hover, but it should be able to sit there.

If you really want that 3D performance, you could try a Perry Pump. It made all the difference in my Saito 1.20. It turned it into a rich-running hog into a powerful, economical engine.

-Pat