hi

the most obvious problem in installing an engine inverted is the tank position. try to position the tank so the center line of the tank is about 3/8 to 1/2 inch below the center line of the ventura or the fuel nipple on throttle. if tank is higher than this the fuel will siphon into the engine flooding it, extinguishing the glow plug. most modern engines will run as well inverted as well as upright with proper set-up.

happy flying
pt19 flyer