That's the culprit then, in my opinion. You have/had an issue with an underpowered airframe. The LA 46 is a good dependable motor, but it's not a powerhouse by any means. On a plane with more wing and a little more forgiving airfoil, and the 46 would probably be fine, but you're flying a relatively aggressive aerobatic airfoil, tapered wings, and not a lot of wing area. Aerobatic planes need a lot of power to keep the wing producing lift. If you're going to really enjoy this airframe, I would say move up to something like a .61 FX, or the Evolution .61. Or the Tower .61 and .75 - stay away from the Tower .46.

If your LA46 were in a 6.1lb trainer, it would fly fine all day long, no issues - maybe even on a 6lb Sig 4*, but to get good aerobatic performance on that powerplant, I would think you'd need to stay in the 5 - 5.5lb range at most. Our club runs a club-rules pylon race and the LA46 is the required engine, cause it's cheap, easy to tune, and durable. On a 4-4.5 lb Lanier Predator Quickie 500 plane with a 10x7 prop- it really moves those light planes around.

I would run no more than a 11x5 or 6 on that LA 46 on 20% fuel.