ORIGINAL: Ed_Moorman

If you left the tank in the stock location, it's no wonder you had problems.

The Pulse was designed for an upright engine with the tank set high in the fuselage. Normally, in a non-pumped and regulated engine, the center line of the tank needs to be in line with to a quarter inch lower than the fuel jet in the carb. This is hole where the fuel comes out in the center of the rotating barrel.

When you invert the engine, the tank is too high. This results in the engine running rich until you adjust the needle. Fuel can also siphon into the carb when you are on the ground. Once you go inverted, the tank becomes too low and your engine should lean out.

Bottom line, you need to adjust the tank height lower to allow you to keep the engine inverted or return the engine to its designed orientation.