You only need two fuel lines coming out of the tank...

When the aircraft is sitting upright one of them will be higher than the other. The high one with the metal tubing bent towards the top of the fuel tank will go to the outlet on the exhaust to provide back pressure.

The other one will go to the engine's carburator to provide fuel. The copper tubing on this line will extend about 1/3 of the way into the tank. Then were will be fuel tubing with a "clunk" on the end. While holding the fuel tank vertical (the outlets on top) the clunk should be very close to the bottom of the tank, but not touching.

This ought to get you started...

I used to have links to some really great diagrams on the web for setting them up, but I can't find anything now. Anybody have those?