I have a magnum 120 on mine, I have the same problem, if I put the fuel line next to the carb on the inverted engine all the fuel runs out of the tank. I cant turn the engine because I already made the cowl fit, I'm thinking of lowering the tank but that doesn't look easy to do. Great planes told me the center of the tank should be even with the carb. How do I fix it with out doing to much to plane or engine