gas tank vent

[bobbysky]

Well I just got my boat lift this last week. I have it setup at a slight angle so that I can just lower it enough to power off and on. I went out yesterday and gas was leaking out the filling hole (even with the cap tightly screwed on). When I unscrewed the cap there was gas just sitting at the top of the fill line. I lowered my boat and started her up and took of and it instantly went back down.

Do you think my vent is clogged or something? I noticed it has a check valve, could that plug up?

[R&T Babich]

The tank is vented to the atmosphere to keep pressure from building up in the tank.
If your boat was tilted nose up the fuel would flow to the rear of the tank and could start leaking out of the fill cap.
When I fill our boat up at home the fuel will leak out of the vent when there is too much fuel because it sits nose low.
Perfectly normal.

Is the check valve you mentioned the one at the fuel tank pickup?
That is to keep gas from being siphoned into the bilge if there is a leak in a hose going to the engine.

The fuel/air separator near the vent is a chamber to allow air in the tank to escape before the gas when filling.
If it was clogged and the engine was running after awhile the engine would starve for fuel because no air would be getting into the tank to allow fuel to be pulled out by the pump.