Bad Gas Leak

[lawton]

I have a 2003 skeeter zx200. Came home from the lake today and parked the boat in the driveway while I went inside and ate lunch. Came back out to clean it and the starboard gas tank (which was almost full) had swelled so much in the sun that it was causing gas to pour out from under the fill cap and run down the back of the boat. I then opened the fill cap (stupidly) and several gallons came flooding out and ran down the driveway. I am assuming there is a vent for this tank that is plugged, does anyone know where it may be?

[GM482V]

If that model has the flip type caps, the vent should be built into the cap.