Follow up question to fuel smell in the salon

[denpooch]

Hey there and Happy New Year to the crew.
A couple of months ago I posted regarding a fuel smell in the salon. After many responses, I have decided to change out the fuel fill hose on both port and starboard this Spring. Folks have noted that hoses can be compromised due to the age of the boat and additives in the gasoline. I have a 2005 Mariner.
I was speaking with a friend and he mentioned that perhaps the fuel 'vent' line is the culprit.
I do not recall seeing any vent line on the boat. My previous vessel had the vents on the hull near the fill which were easily observed.
Do all boats require a fuel vent line?
Does the Mariner have a fuel vent line? If so would you know where they live.
Many thanks.

[g36]

If you don't see the classic looking vent close to the fuel fill the boat may have fuel fills with a incorporated vent but it will have some kind of venting.
https://www.perko.com/catalog/fills_and ... inch_hose/

[km1125]

You could start at the tank and identify the fill and vent hoses... and then trace them back to where they connect on the hull or deck.

[Viper]

All fuel tanks will have a vent line. Whether the line vents through the hull or the deck fill assembly will depend on the application. Newer builds have more complicated fuel storage systems to minimize venting vapors to atmosphere. Usually it's the fill hose that fails as it's not very often that the vent hose has fuel in it unless the tanks were in a habit of being overfilled. It pays to check all hoses while you're in there though.

[plittle2005]

Stop right here! If you have ANY gasoline odor detectable in or on the boat (except while filling) you have a potential explosion and fire situation. Don't ask me how I know!

Before operating this boat again, you MUST find the source of leakage and eliminate the leak. ANY gasoline odor is unacceptable!

That said, the fuel fill hose is a likely culprit on a boat of that age, or the tank spigot flange gasket. It is less likely (although still possible) that the aluminum tank would be leaking due to corrosion or seam failure.

Another POTENTIAL source of leakage would be if filling full on a cold day, and then the ambient temp. goes up substantially, the fuel could be expanding and being pushed out the vent, or out the fill flange on the tank top. But if the level is lower then the odor is coming from a lower source and is even more serious because it will be continuous.

Remember, one cup of gasoline, fumed, equals 6 sticks of dynamite. Good luck finding your leak!

[denpooch]

Thanks crew.

[Jay Fusaro]

Plittle2005 is 100% correct. If you have your owners manual that should show you where the fuel vent is. Also, I had a 1998, 350 mariner and had a fuel smell right after the boat was manufactured. It ended up being that the fuel line was not securely connected to the fuel deck fill. It was loose. Be sure the fuel line is clamped correctly and securely to the fuel fill deck plate.

[Wsullivan71]

All good replies. Here is what my fuel fill hose looked like when I changed it after buying the boat!

[Viper]

Wow, that's pretty bad for its age.