bruce,this is from one of the links here,If the tank has a bubble section, position the muffler pressure/
overflow brass tubing inside the bubble for maximum tank capacity. Most fuel tanks include enough brass tubing to fabricate any three-line system.
Try to reach into the bubble with as straight a brass tubing !QUOT!run!QUOT! as possible. This helps prevent the fuel !QUOT!pickup!QUOT! line from wrapping itself around the vent tubing and getting STUCK in a full forward position, which could cause the engine to quit during the next vertical maneuver,or cause a lean run condition.also run the pressure line or vent line too far into the fuel tank and have your airplane sitting ready for your turn in the box and see how much fuel siphons in the muffler and even engine.sorry for not going into detail that was my meanning.he said fuel was coming out of the carburator like the engine was flooded.