Furnaceman:

The Evolution .46 will run just fine at almost any angle.

However the FIRST thing you MUST do is remove the blue collars on both of the needles.

Then take out the high speed needle and put a TINY bit of lock tite blue on the threads, no where else.

Push the carb down hard as you tighten the retaining screw, and tighten all of the cap screws as they come loose early on.

Finally assume that your plane is completely UNTUNED and re-tune it, or have someone do it for you.

The engine runs in all attitudes, but it has a slightly tighter tolerance when it is inverted.

If you get deadsticks either retune or look to your fuel system...