Have an Enya 1.55 4-stroke with Cline regulator and on board glow driver. The engine is working well except for one problem. Often when I roll inverted the engine will miss just as I reach inverted position. It will keep on running inverted OK. Also if I push from inverted to upright level flight the engine dies just as I come over the top at full throttle. I suspect the cause may be related to fuel lines or tank, but have checked and all appear OK. Appreciate any suggestions.

TIA