Water in gas tank

Unchained · Post by **Unchained** » Tue Oct 30, 2012 9:49 am

I started having problems getting my port engine started and have found that I have water in the gas and itâ€™s cloudy looking. I had the same problem last year, had the tank pumped out and replaced a dry/cracked O-ring at the deck fill suspecting that was the main problem. I was told to check out the tank vent to see if water might be getting in that way, but Iâ€™m not sure where this is located. I have twin 125 gallon tanks. Can someone point me in the right direction? Any other suggestions on how water can get in? Thanks. Mike.

aweimer · Post by **aweimer** » Tue Oct 30, 2012 12:07 pm

Should be a brass breather on the side just next to the tanks.

BobCT · Post by **BobCT** » Tue Oct 30, 2012 1:31 pm

Metal thru hull w/screen. Up high on each side.

Unchained · Post by **Unchained** » Tue Oct 30, 2012 8:06 pm

Thanks guys, sounds like it's easy to find. I'll take a look when I am out there on Saturday. Maybe next season we'll have better luck. No matter the problems though, I still love this boat.

Big D · Post by **Big D** » Tue Oct 30, 2012 8:42 pm

As mentioned, there will be a vent out the side of the hull for each tank. Probably chrome with screens covering the holes in the fitting, they MUST have screens. Follow the vent hose from the top of the tank to the hull for the location of the vent. While you're down below following the vent line, take note at the path it takes. Ensure that it leaves the tank and goes uphill toward the hull fitting with no sags. This is important so that any overflow will not get caught in the sag and prevent ventilation. It's important that the vent fitting at the hull have a 90 degree elbow on the inside of the hull pointing upward such that the vent line coming from the tank is looped above the vent then down to the 90 deg elbow in the fitting. This prevents any water/wash that gets in through the fitting from going down the line to your fuel tank.

This may not be easy to determine but how much water are we talking about? You also need to consider your source for fuel, maybe they have water in their tank, and the possibility that this may be the result of ethenol fuel usage and the moisture it naturally draws out of the air. You'd be surprised how much water from that and condensation can accumulate in a fuel tank. Do you have water separating fuel filters installed?

Unchained · Post by **Unchained** » Tue Oct 30, 2012 9:46 pm

This is great information. The gas in my other tank is fine and was ok all last year too. This is why I suspect water coming in from somewhere. I have a Racor 10 micron fuel/water separator and a second Fram fuel/water separator on both tanks feeding each engine. I replaced both on the port side just 3 weeks ago when I started having problems keeping the engine running and they were filled with water. Now the new ones are filled again.

Big D · Post by **Big D** » Tue Oct 30, 2012 10:00 pm

Check the items noted above regarding vents and hose paths. The only other way for water to get in is through the deck fill fitting. It is marked "GAS" right?

Had to ask, seen this happen a few times.

Unchained · Post by **Unchained** » Wed Oct 31, 2012 8:04 am

Yes, I have heard of that happening, but that's not the case. I will check out the items you listed. Thanks Big D.

Allen Sr · Post by **Allen Sr** » Wed Oct 31, 2012 5:15 pm

How about a neighbor washing his boat and 'accidently' spraying your vents and water intruding that way?

Just an idea.

prowlersfish · Post by **prowlersfish** » Wed Oct 31, 2012 5:41 pm

Allen Sr wrote:How about a neighbor washing his boat and 'accidently' spraying your vents and water intruding that way? Just an idea.

And thats a good reason to have the hose go up hill first

Lawman · Post by **Lawman** » Sat Nov 03, 2012 2:37 pm

Big D wrote:Check the items noted above regarding vents and hose paths. The only other way for water to get in is through the deck fill fitting. It is marked "GAS" right? Had to ask, seen this happen a few times.

+1 I use a little Petroleum jelly and smear it over the gap all around the gas cap once you have screwed it down. Water runs right over it and you can put on a new layer everytime you fuel up.

Unchained · Post by **Unchained** » Thu Nov 08, 2012 8:55 am

Thanks for all of the great input guys! I just got a look at it and found the problem. The little plastic surge device that is part of this setup had come apart and the end from the tank, which was about 6" long, was pointing straight up. Directly above there is where the two vent hoses connect to the louvered fresh air intake, if that's the correct term. Anyway, one of the vent hoses had come off and when it would rain, the water came in through the louvers and leaked down the opening, right into the tank hose. Hopefully no more problems after this is fixed and the bad gas is pumped out. I'm going to check the other tank setup as well and replace that surge device too.
Are these devices a good idea? The opening is much smaller than the hose itself and looks like it doesn't let the tank breathe enough.
Any thoughts on this?

Mike

Big D · Post by **Big D** » Thu Nov 08, 2012 9:26 pm

Surge device? I'm assuming this is in-line on the tank vent hose, if so, it is a check valve that lets air in but will not let fuel out if tank is overfilled so it doesn't spill over the side through the vent fitting. Good to have, I've installed a few.

prowlersfish · Post by **prowlersfish** » Thu Nov 08, 2012 9:29 pm

Photo ?

rickalan35 · Post by **rickalan35** » Fri Nov 09, 2012 7:37 am

I don't really follow. Please explain again if you get time. Don't believe I have anything like this on my tri