Gas seeping from fill cap

[badrano]

My boat is all winterized including a full tank of gas. I thought this problem went away, but once again I'm smelling a gas odor.
Looking at the boat, gas is somehow seeping from the gas cap, running down the trim to a point just past the through-hull drain fittings and then dripping to the ground.
The first time I noticed this, the trail followed the trim and seeped across the bottom side of the swim platform and down the transom. The pic below (not mine...grabbed pic from Google) shows the trail.
What can I do to stop this as it is staining the gelcoat?

 

[alldodge]

Don't fill it up.
My Rinker use to do the same thing and only happens when it gets warm if I filled it up. Gas expanded do to getting warmer then when it was filled.

 

[ahicks]

I agree. When the nozzle clicks off the first time, do not add more for any reason.

 

[badrano]

Don't fill it up.
My Rinker use to do the same thing and only happens when it gets warm if I filled it up. Gas expanded do to getting warmer then when it was filled.

That's what I thought. This didn't happen with my 204 but then I never went to the station, filled her up after doing all the winterization. With the 204, I filled it up, brought it back and then winterized it which meant running the engine to do the oil change....I burned fuel doing all that so it wasn't full full.

After the first time it happened, I bought a fuel hand pump thinking I'll pump some out but the tubing isn't rigid enough to push down the fill hose in to the tank.

 

[alldodge]

It doesn't burn much at all doing winterization. Depends on how warm it gets. Then if it sits with the bow up a bit higher then when hooked to the truck, this also can add to the issue

 

[JimS123]

It must be really hot weather for the gas to expand that much. I would look at the gas tank vent.

 

[ahicks]

Seems like the vent would (should) be placed a little higher than the fill, to prevent full tanks from draining there?

 

[cptbill]

Check the venting system, I'm not a big fan of that system that's built into the fill/cap

 

[JimS123]

Seems like the vent would (should) be placed a little higher than the fill, to prevent full tanks from draining there?

It would seem that way. Nevertheless, the 2 most recent family boats purchased had the cap just above the rubrail, and the vent about 6" below it.

 

[mike_i]

I've had that happen many times when the weather got hot. Gas would come from the vent which is a couple of inches above the gas cap. As others have said don't top the tank off. Does the tank vent thru the gas cap or is there a seperate vent?

 

[MRS]

Loop the vent hose so the top of the loop is higher than the vent it worked on my old boat. Might work on yours worth a try.

 

[ahicks]

Loop the vent hose so the top of the loop is higher than the vent it worked on my old boat. Might work on yours worth a try.

THAT'S how they could get away with the vent being lower than the fill!

The top of that loop would be the only thing that needs to be higher than the fill.

 

[MRS]

Yup

 

[tpenfield]

Combo gas fill & venting cap?

Don't fill the tank

The vent line probably has fuel in it from being so full, and the combination of vapor pressure and temperature expansion is forcing the fuel out of the tank.

 

[dingbat]

Combo gas fill & venting cap?

Yep...have them on both fuel tanks.
Pretty common config anymore