Fuel line plumbing is a little unusual in this model for a few reasons. First, there are two engines; second, the engines are well above and to the rear of the fuel tank; third, the tank has to be vented to atmosphere instead of connected to the pressure tap on a muffler; fourth, I didn't like the idea of filling and draining the tank by disconnecting one of the fuel lines within the engine nacelles, so I added a separate fill and drain port.

In typical set-ups, only two lines are needed from the tank, one to the engine and one to the muffler. The tank caps (inner & outer) and plug are predrilled for three lines, but only two are drilled completely through the rubber plug. I had to open up that third hole as well as drill a fourth completely through the plug and inner & outer caps. Each engine gets its own fuel line from tank clunk to carburetor.

With the engines being both remote from, and well above, the fuel tank, I'm using a Perry pump on each to assure good fuel flow. When using these pumps, the fuel tank has to be vented, but not pressurized. The vent line will also act as an overflow port during filling.

I'm using a Slimline Excel Fueler to fill and drain the tank. Normally, the top of the fill port is connected to the fuel tank while the side port it connected to the engine. When the engine is running, fuel flows through this fitting. I wanted both engines to be plumbed exactly alike, so I'm using the fitting as a fill and drain port only and capped the port on the engine side. The tank will be filled when the plane is upright. When finished flying for the day, excess fuel will be drained when the plane is inverted to remove the wing.