John, I've got a couple planes that I basicly use a 2 line setup with extentions through the cowl for fueling and defuling. I've also got a couple that that system just isn't pratical, and a three line setup is required. My first choice in a setup is an open engine so I can get to the lines with no problems. I say lines because if I can, I use a closed system for fueling and defueling. I run the vent to the top of the jug for both fueling and defueling, although I seldom defuel a tank, but rather plug both lines at the end of the day. Again, the pesky exceptions get in the way and defueling isnessary, so a good three line setup is required.

Gene, i've had two of the tank bungs go south on me in the last year. They do tend to take s set when installed then shrink from there. It sure makes one glad that they put a drain in the tank compartment and also didn't built the tank in place.

Don