Wendell,
The OS 160 will run on normal size fuel tubing. DON'T use a fuel filler valve. They sometimes leak and they add weight. Fuel line setup is simple: 2 lines - run the overflow line out to the bottom of the plane somewhere. Run the other line from the clunk to a Tettra Large 90 degree fuel outlet (part # 4214 - Central Hobbies has these) located on the side of the fuse near the nose of the plane. This will bring the fuel outside of the plane so that you can fill and drain the tank as well as pinch the fuel line if you want to. About 1 - 2 inches in front of that fitting, install another one to bring everything back inside the airplane. Attach a fuel line to this fitting inside the airplane and then run it through the firewall to your pump inlet. Make sure you install a good fuel filter in this line so that the pump is protected. Then just run your pump outlet to the needle valve. I like to install the needle valve on the airplane NOT the engine. Easy. The only thing you need to be careful of is the pressure line that goes from your engine crankcase pressure port to the pump. Make sure this line is short (about 3" or less). To fill and drain your tank, just remove the short hose from the forward fitting on the outside of the plane and attach that hose (still connected to the rear fitting) to your fuel pump - the rear fitting is connected to your fuel tank - remember? I'll try to get some pic's for you when I get back in the shop.

John Pavlick
Team Black Magic