Anti-syphon valve ?????

[axespino]

When I had my saddle tanks I would have a problem after half of the tank was empty. It turned out that the boat sat for a long time with half a tank of gas and the dip tube above the gas line became pitted with holes and when I got below that point it started to suck air. I put a temporary tank and it ran fine so I plugged the dip tube at the top of the tank and had some fittings welded 1" from the bottom for my suction hoses. No problems after that