Scott...if you are able to refuel without spilling it just isn't that rough yet. Where I boat it can get way to bumpy to fill the tank without fuel sloshing out. The tee in-line set up only needs backflow preventer valves installed to make the system work. One valve on the carb side of the tee and one valve on the fill side. To fill, close the carb side and open the supply side...pump fuel in and reverse valves to run.