Interesting. My current build is a TF Corsair, with an RCV 120 SP 4 stroke. I was thinking about this after my previous post, and think I have a good solution, that is both clean, and fairly simple.

I'm planning on installing a refueler valve assy [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXD745&P=0]Dubro Refueling Valve[/link]

I will now be installing 2 of them. One for the fueling line, and one for the pressure line. The valve stops flow when the kwik fueling probe is inserted, so that it can only go in one direction. So, by installing both 'nozzles' you can fill with one, and catch overflow with the other, and alleviates the need to disconnect from the muffler, which I will not have access to once the cowl is installed.