Could someone tell me how to hook-up a fuel tank to the engine, both 2 and 3 tubing installation? I'm building an Hobbico ARF and the motor I'm going to use is a Magnum 61. It's pretty close quarters to dress the fuel tubing. I'm worried about how to fill the tank. The third line seams to be the best solution, but what about the possible air leak when the fill line is plugged?

Thank,

Greg

An easy solution is to use a Du-Bro fuel valve. It uses 2 lines. The fuel supply line is disconnected while fueling so the engine doesn't flood. The overflow goes to the muffler which should be disconnected to avoid filling the muffler with fuel.

2 line set up:
One line from the clunk to the engine. A filter can be used before the carb to keep it clean. Over-flow line to the muffler. (Fill the tank from behind the filter if one is used).

3 line set up:
Same as 2 line except the 3rd line if used for over flow. It must be blocked so the engine will get muffler pressure. (I don't use or recommend this).

EXCAP232

Three line : one line to the clunk --- this should clear the dead center of the back of the tank when held upright. This connects to the carb.
second line to the vent . The metal tube should just clear the top of the tank inside.
third line to a second clunk (if you plan on de-fueling) or just inside the tank if you don't. This is the line which is plugged after filling. Anything can leak but seldom is it the "third line". A 4/40 by .25" screw will work well (assuming medium size fuel line).

Two line : same as one and two above. Just omit the third line. To fuel/de-fuel unhook the line at the carb. If your installation wont allow it (cowl etc.) then use a DuBro filler valve or the equivalent.

If the plane has a cowl, the Dubro fueler is probably the best option. If not, there is another option for a 2 line setup.........
Sometime quarters are so close that it isn't easy at all to disconnect the line to the carb for each fuelup. I use a hand crank fuel pump and install the GP fuel fittings (around $10) set into the cap of the fuel jug. Here's the setup.

From the LHS get a "T" fitting. Make sure the ID of the "T" is at least as large as the ID of the tubing you're using. Install the "T" in the line between the fuel tank and the carb/fuel inlet. Attach a short piece of tubing to the 3rd. leg of the "T" just long enough to extend upward and clear of those cramped quarters. This will be the fuelup point. Rather that plugging this line by running a screw into the open end after fueling, the LHS should also have a plug or the plug used by a fuel dot. Also, there are small clamps available to put around each connection of the "T" to lessen the chance of leakage.

The fuel jug and fittings set.....to pump from the jug, a piece of tubing goes inside with a filter on the end. The pump is connected to one fitting installed in the cap that is connected to this tube. The pressure/muffler line is removed from the engine and connected to a piece of tubing going back to a second fitting installed in the jug cap (a closed loop type of setup). All these fittings are included in the set...just need to purchase a few extra feet of tubing. When the tank is full, the overflow flows back into the jug. Then, reconnect the muffler line and insert the plug into the "T" that was used to fill. To defuel the tank, simply reverse the pump direction with the same connections until the tank is empty.

Others probably have more if not better suggestions but this one works well for me.