Persistent water intrusion in fuel 19.5 tournament

[Ray400]

This problem just doesn’t want to go away . I have changed the seal on the gauge sensor, replaced all the deck plates, checked all hose connections , fill is above deck so water leak seems unlikely. vent is integral to fill fitting but don’t see how water could enter that either. Water does pool above gauge sensor and I am thinking that my new seal might be leaking again. Now thinking I might pressurize tank if possible from fuel outlet if possible.
hoping this year I can ditch the portable tanks and go back to internal tank but just pumped a quart of fuel out and container was half water! Poly tank with no access panel so I am resisting removal unless no other option.
thoughts anyone? much appreciated

 

[seasick]

I am confused. Is the poly tank the one getting water? If so is that the original below tank poly tank?
Why does water pool over the sender?
Have you replaced the o-ring on the deck fill fitting ( is there an o-ring??)
From where, did you pump out the gas that was half water?

 

[Ray400]

Yes it is the original poly tank and there is a slight depression in the poly surrounding the sender.
there is no O ring on the cap it is not at deck level but above and I am pumping water through the fuel line that feeds the motor. I put four gallons in this season as a test but will remove all of it this morning.

 

[DennisG01]

Even those integral fill/vent fuel fittings still have an o-ring in the cap. It's probably a Perko cap? A knurled edge that, usually, you just spin off with your palm? But it still has two holes for a key?

 

[Ray400]

Yes that is correct knurled cap I will replace o ring
just pumped out remaining 2 - 3 gallons appears mostly clean so most water came out in the first 1/2 gallon pumped yesterday

 

[seasick]

Yes that is correct knurled cap I will replace o ring
just pumped out remaining 2 - 3 gallons appears mostly clean so most water came out in the first 1/2 gallon pumped yesterday

Your gas tank could have had water for a long time unless you pumped it empty using the sender opening. The regular pickup sits above the tank bottom with about an inch of space. When the boat sits at rest the water is level but when you get on plane, the hull sits at an angle and the fuel and any water move aft making the level of the water higher. When the level is higher than the pickup tube, all you pump ot to the motor is water.
Check that o-ring in the combo fuel fill.

 

[Ray400]

yes that is next step i will remove sender and get every drop out. i am also thinking of using a sealant instead of the rubber gasket for the sender.

 

[wspitler]

Depending on the size of your tank and the number of hot cold cycles and humidity in the environment if left near empty a large tank can generate a pint of water every few months from condensation alone.

 

[Mustang65fbk]

Agree with wspitler's above comment. I try to use ethanol free fuel whenever possible but if you don't use that, or have that as an option where you live, you could potentially see quite a bit of water in your gas tank if it's been sitting for quite sometime. I'd recommend replacing your fuel water separator annually and only using ethanol free fuel if possible.

 

[seasick]

In general, if the flange is flat and all the screws work OK, sealant is not advised but it isn't the end of the world if you do. There are two things to pay attentions to: The sealant if used has to be suitable for gasoline, many are not. Secondly do not overtighten the screws. Doing so can distort the flange ( although that is more common in metal tanks and not poly)

 

[Ray400]

Interesting point re condensation. Tank was empty all winter because I was using portable tanks last summer. so it’s very possible recent water is from condensation. I Cannot get ethanol free fuel in NY - at least here on Long Island

i do think I will attempt to pressurize tank from the fuel outlet though to see if anything is amiss before putting in 50 gallons ...
appreciate all the advise here Tnx

 

[seasick]

There may be an anti-siphon valve on the pickup connection. That may block air from getting into he tank. You nave to also close off the fill and vent lines. You may be able to do that by sealing off the fuel fill hole.
Finally do not exceed 3 psi. It is not all that hard to overpressure and damage the tank.

 

[Andrew93]

We had a 2001 180 Sportsman with the poly tank. It was drinking water around the sending unit. The top of the tank flexed and pulled the screws out of the fasteners. I found a stainless plate online and through bolted that with a lot of fuel rated sealant with the cork gasket and put in a new sender. It was good after that. Those poly tank flex and the imbedded nuts corrode. Its a bad design in my opinion. Here are a few pictures fo the repair, I was happy with the result

 

[Mustang65fbk]

Interesting point re condensation. Tank was empty all winter because I was using portable tanks last summer. so it’s very possible recent water is from condensation. I Cannot get ethanol free fuel in NY - at least here on Long Island

i do think I will attempt to pressurize tank from the fuel outlet though to see if anything is amiss before putting in 50 gallons ...
appreciate all the advise here Tnx

Pressurize the tank because of what... you suspect there's a leak somewhere? For gasoline, or other things that have a strong smell to them, you should be able to quite easily detect the smell of leaking gasoline and/or see a bunch of runoff in the compartment wherever the tank is located. Even if there's a leak up on top of the tank or the seal isn't doing a good job, you should still be able to smell the scent of gasoline. If there's no smell of gasoline and the inside of the compartment is dry, I'd be willing to bet you don't have a leak, especially if you can't smell anything when the fuel tank compartment hatch is taken off. I'm still thinking it's the fact that the OP lives in NYC where it gets rather cold during the winter, and I'm assuming this is the first time he's attempted to de-winterize the boat for the season? I'd be willing to bet it's condensation buildup in the tank from sitting all winter and as mentioned above, that he isn't using ethanol free fuel.

 

[Ray400]

3 psi ? Good to know I would have gone quite a bit more if you hadn’t mentioned that Tnx!
andrew 93 - when I replaced the sender and gasket I did examine those embedded nuts and all seemed ok but see they will be a problem eventually. I seem to be getting a good seal at this point and all the bolts are tightening down well. BUT I like the idea of a stainless blade to strengthen that spot. If you recall where you got that plate please pass me the source Tnx
mustang - I am also beginning to think it might just be condensation from past storage and lack of use. It didn’t make a lot of sense to me to fill the tanks with fuel if I am using portable tanks. Could even be two winters of empty fuel tank.

 

[DennisG01]

Generally, plastic is much less susceptible to condensation than aluminum tanks and an empty plastic tank is pretty much immune to it.

Yup - definitely don't use more than a couple pounds of pressure. There's really no need for more, anyways.

If I understood you correctly, you said there was no o-ring on the cap? I think you found the issue.

 

[Ray400]

Can someone clear up the O ring question in the type of fill fitting that I have ?
I went down to look at the cap and it is the screw cap with the knurled edge almost like on a classic car. There is a rubber type gasket on the fitting that the cap screws down upon. I went over to another Grady at my marina of a similar year and examined his cap which is identical to mine and no O ring present
This is not a perko style flush deck fitting where an O ring would be an obvious seal.

 

[Mustang65fbk]

mustang - I am also beginning to think it might just be condensation from past storage and lack of use. It didn’t make a lot of sense to me to fill the tanks with fuel if I am using portable tanks. Could even be two winters of empty fuel tank.

That's why I typically leave the tank at 3/4 or close to a full tank of fuel with a fuel stabilizer every winter.

 

[seasick]

Regarding the 3 psi, if your tank was 2 feet wide by 3 feet long, the area is 864 square inches. Multiply that by 3 pounds per square inch and you will realize that the total force applied is 2592 pounds!
In addition, 3 psi is the ABYC spec for certification.

I am not familiar with the filler you described. You did say it was a combo fill, fuel and vent. Is that so. If it is how does it vent. On the Perko combo units there is a sort of one way vent in the cap itself that will let air in when a small vacuum is in the tank. Also on the Perko style, if it was designed to have an o-ring, there will be a groove on the neck of the cap, right below the flat edge on the underside of the cap. The groove is where the o-ring would sit.

 

[DennisG01]

Can someone clear up the O ring question in the type of fill fitting that I have ?
I went down to look at the cap and it is the screw cap with the knurled edge almost like on a classic car. There is a rubber type gasket on the fitting that the cap screws down upon. I went over to another Grady at my marina of a similar year and examined his cap which is identical to mine and no O ring present
This is not a perko style flush deck fitting where an O ring would be an obvious seal.

"Perko style" is not descriptive - meaning, Perko is a brand and makes different styles... and there are other brands of fills that may/may not look like a Perko.

The "knurled edge" sounds like a Perko brand - it would also have two holes for a gas key, but usually your palm is all that you need. This style does, indeed, have an o-ring near the top of the screw thread portion.

However, the "rubber gasket" sounds different. Go to Perko's website and look at their fills to try and match up what you have. There is a possibility that a previous owner either changed things around or even added that gasket. It's the "previous owner" syndrome... you never know.