G'day Mate,
The only time you will have trouble with inverted motors, of any type, 4 or 2 stroke, is if you tank height is not right, that is needle valve on carby, level with, or up to 3/8" lower than the needle valve. It must be at the right height, because if it is too high, & that is usually the problem, the fuel will siphon into the carby & cause BIG problems, fuel lock & bent conrods & so on.
Another solution, if it is a problem getting the tank low enough, might be to have the motor at 90 degrees (side on) that way you muffler will exit under the plane, & help keep it clean, just a thought.