What is it?

[dfast7181]

The other day I was filling the boat with fuel and while doing so a thick, honey/yellow colored, clear, liquid starts to ooze from the fuel tank vent out on to the deck. Any ideas on what this is? The fuel in the boat was about 6-8 months old. I use an additive to keep the fuel stable and prevent microbes/algee growth. Even the guy at the fuel dock didn't know what it was.

 

[Peggie Hall HeadMistress]

Whatever it is...

It's at least a partial obstruction in the vent line that shouldn't be there. It's just important that fuel and water tank vent lines be completely clear as it is that holding tank vent lines never become blocked. , 'cuz ALL tanks need an escape for air displaced by incoming contents--i.e. filling the water or fuel tank...and a source of air to replace contents as they're pulled out by the pump--i.e. fuel pump, fresh water pump. If the vent is even partially blocked, it'll interfere with filling the tank and make it hard, if not impossible for the water or fuel pump to pull anything out the tank.

So I'd replace the vent line if I were you. Make sure that you use hose rated for fuel...it'll most likely be the standard 5/8" diameter, but take a piece of the old one with you when you buy it.

 

[kloudie1]

Woah.. doesn't sound good !! The line and vent itself should be cleaned because if it is coming out when you are filling, it will be going into the tank when the engine is running and emptying the tank.. Probably some kind of water/bug gook from a critter making a nest in the vent..or it could be old fuel residue.. In any case, you have a low spot/trap that is accumulating liquid. That low spot should be reconfigured so that it does not trap liquid. The vent line should run uphill from the tank to a high spot under the deck somewhere, then back down to the vent, with no traps..

 

[dfast7181]

Thanks Peggie and Kloudie1 for the responses. Never thought about it clogging the vent so thanks for bringing that up. Next time I'm at the boat I'll pull the vent hose and have a look. If I ever find out what it was/is I'll let everyone know.