[dcb]

This is how RC airplanes work actually, a little pressure tap on the muffler pushes the fuel to the carb. It's only pressurized while the engine is running, and is a pretty damn simple setup. It is low pressure though, and most everything I know of has gone the route of high pressure. That is not to say an accurate low pressure system is impossible or anything.

But if you are thinking of a high pressure system, then you still have to pump something (air instead of fuel) and you would lose out, energy wise, and that whole high pressurize tank thing that would have to be a lot heavier to handle the pressure without distorting, etc.