You guys should go to the glow airplane engine forum and search for pump and/or regulator. [link=http://www.rcuniverse.com/forum/forumid_114/tt.htm]http://www.rcuniverse.com/forum/forumid_114/tt.htm[/link]

I had problems with my 4-stroke dying after rolling and abrupt stops. I learned a ton of info from the plane guys. There are pumps and regulators available.

I started out trying the Cline regulator [link=http://www.billsroom.com/pcfs/]http://www.billsroom.com/pcfs/[/link] which is a one-way valve in the pressure line from the muffler to the tank and a pressure regulator to the carb. I had problems with it, maybe it was the spring loaded stopper on the tank or the size of the engine but I could not get enough fuel. It would probably work with the stock engine.

I actually have an electric fuel pump from a RC jet company now. It pumps from the tank and back to the tank with a tee in the line to the Cline regulator. The regulator now get a constant low pressure supply of fuel no matter what G-forces the truck sees. I don't have the pump info now but it is tiny and very low current at the approx 1.5 volts I'm running it at.

I also made a fuel bladder tank using an airplane tank and a plastic bag. It seams to be working very well and will keep running upside down while I leisurely walk over to get it

I can take some pics and get the pump info if anyone is interested.