Gas Cap Venting

Throttle1971

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I have a 2005 GW 232 with twin tanks (Aux and Main) that have Perko gas caps. More than one occasion if I fill the tanks up to the top the pressure will allow some of the gas to leak out from the caps and down the side of the boat and in the water. Especially from the Main gas tank. From reviewing the manual it appears that the gas vents at the base of the gas fill. I have put on two new gas caps and new rubber o rings. Anyone else experience this issue?
 

wspitler

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The caps are vented and if you fill the tank to the top as it heats up, even slightly, the air (if any) and gas in the tank expands. Normal occurrence. Happened to my tanks and I didn't think I had topped them off, but must have!
 

seasick

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The gas nozzle should have tripped off before the gas reached the top of the filler neck. When that happens, stop adding gas (topping off). Simple as that.
 

Throttle1971

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So it is normal that if you overfill the gas will leak out of the cap? What keeps water from leaking in the cap if gas can leak out?
 

seasick

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So it is normal that if you overfill the gas will leak out of the cap? What keeps water from leaking in the cap if gas can leak out?
The cap has a one way valve that lets excessive pressure out.