[QUOTE=izzy-israel- Could someone please give me any suggestions on what the problem could be?[/QUOTE]


Failure to maintain the same fuel tank to spraybar (jet) relationship in the inverted position as it would be in the upright position.

That's the bottom line your tank is too high! This happens often when the fellows invert and do lower that fuel tank to match how much the spray bar was lowered.

Lower that tank, get out the chainsaw to do so if necessary or just mount the engine sideways.

John