How Is Water Getting In My Gas Tank?

[Noob2U]

OK so I allow gas to pool around the fuel fill door then take a candle to it...right? check!

(just kidding)

We have a list of ideas to catch the culprits and determine tampering but, I'm finding it so hard to believe.

This is what I know. Water Wins. The boat is about 8 years old and I'm afraid something has dried out/rotted/eroded over time and it's probably something that would cost more to get to than the boat is worth.

[FAST FRED]

If the tanks are below deck , folks from the BRONX would use crazy glue to install a few double edged razor blades in the area of the fuel cap.

EZ to check at the local emergency room to see who came in with GUSHERS!

FF

[mongo75]

YES, a lit candle is safe around a gas cap. Jeez, as smart as most of you guys are I sometimes wonder- here's why. (1) the cap is sealed, so no vapors escape (2) gasoline vapors are heavier than air, so therefore they do not go up to the lit candle, but away from it. So before y'all go running around yelling the sky is falling, remeber your science class.

Originally Posted by mongo75

(1) the cap is sealed, so no vapors escape (2) gasoline vapors are heavier than air, so therefore they do not go up to the lit candle, but away from it. So before y'all go running around yelling the sky is falling, remeber your science class.

To your (1): it is not! usually the cap has to act as a tank vent, through a labyrinth!

to (2):
read:

Originally Posted by Noob2U

OK so I allow gas to pool around the fuel fill door then take a candle to it...right? check!.

A gas pool of course will ignite immediately.
so far to the being smart comment.......................

He's already done the most obvious - greasing new O-rings and installing caps tight. Maybe it's the bug/flame screen in the vents. Is the water in both tanks? Does the engine have a fuel cooler? That's a likely culprit if so...and they aren't even needed in temperate or cool climes.

[ancient kayaker]

If vandalism is not the cause, with two mechanics not able to figure it out the real cause is an obscure one. Try to find out when it happens -this may enable the mech to diagnose the problem correctly next time.

Water is either getting in during a trip or while it's sitting on the trailer, and it's either a background activity or a sudden event that can be linked to an external cause.

If you can get a dip tube or other device that will detect water down to the bottom of the tank a regular intervals and before and after a trip, you may get the vital clue. At the least you should monitor the indicated level regularly and especially after rain for unexplained increases and to estabilish if it is gradual or sudden. The amounts of water you have experienced should show up clearly.

[FAST FRED]

Not all boats will vent with the tank cap, most with fixed tanks will have a vent line that goes overboard.

Could this outside vent be installed upside down and work as a rain catcher?

FF

Well thats why I asked:

Originally Posted by apex1

Before you shoot a neighbour bringing back the borrowed drill: does your tank probably have a separate ventilation (not the filler cap labyrinth)? And if so, where does it end?
Regards
Richard

[mongo75]

Originally Posted by apex1

To your (1): it is not! usually the cap has to act as a tank vent, through a labyrinth!

I don't know if gas caps are made different in Germany, but I have NEVER seen a cap in the US that has given me any kind of impression that it will not seal 100%- no vent what so ever. Hence every tank having an overboard drain.

[pistnbroke]

water in tank easy ......stop pissing about ....

Originally Posted by mongo75

I don't know if gas caps are made different in Germany, but I have NEVER seen a cap in the US that has given me any kind of impression that it will not seal 100%- no vent what so ever. Hence every tank having an overboard drain.

You should look in boats, not helicopters! Others have seen that..........

Originally Posted by FAST FRED

Not all boats will vent with the tank cap, most with fixed tanks will have a vent line that goes overboard.
Could this outside vent be installed upside down and work as a rain catcher?
FF

[naturewaterboy]

My 2 cents worth is that your tank vent is letting water in if the water gets in while using the boat. But I'd check both the fuel fill hose and the vent hose, and check the tank. Another likely location is the fuel level sender assembly - it mounts in a big hole that is screwed onto the tank with a gasket. With the amount of water you are getting, sounds like maybe the gasket is bad or missing a screw, and the tank top holds water, funneling it into your tank.

[Luckless]

Rather than going back and forth on the issue of a candle flame near a gas tank, why not try an option that doesn't involve a candle? A small dab of caulking, or a tiny strip of red construction tape will do just as well.

[naturewaterboy]

What would a strip of tape do, and what is chalking? I like the suspense of candles near gasoline - you live life to the fullest when your close to death!

[powerabout]

fill the tank right up to just below the filler cap and then wait to see what happens