Getting water in fuel tank

You know the drill..

Moderators: Redneck_Randy, badmoonrising, lakerunner

Post Reply
Message
Author
bkvanbek
Posts: 7
Joined: Fri Jul 14, 2017 8:02 pm

Getting water in fuel tank

#1 Post by bkvanbek » Wed Jul 28, 2021 4:24 pm

Our 2016 Premier with a 115 Yamaha is getting water in the fuel tank. It has Sea Legs and sometimes when it is loaded we get water flowing over the tank, that is in the transom. There is four penetrations in the top of the tank. Three, the fuel filler, fuel gauge unit,and inspection cover have multiple screws around the perimeter and a rubber gasket. I took these apart and applied a gasket maker/sealant to these. The fourth, the fuel supply fitting bulkhead has no visible gasket and I don't know how it is suppose to go together. I did not take the nut off, as I don't know if it may fall apart in the tank, so I just piled the sealant around this fitting.
What is the most likely cause of water getting into the tank? How are the fuel supply fittings put together?

User avatar
Rick McC.
Posts: 419
Joined: Fri Mar 31, 2017 7:12 pm
Location: Weeki Wachee, Fl

Re: Getting water in fuel tank

#2 Post by Rick McC. » Wed Jul 28, 2021 8:31 pm

The worst problems I ever had with water in the fuel was caused by water in the storage tanks where I bought the gas.
Rick

Sights are for the unenlightened.

User avatar
steve1313
Posts: 679
Joined: Tue Aug 22, 2017 6:33 am

Re: Getting water in fuel tank

#3 Post by steve1313 » Thu Jul 29, 2021 4:57 am

Rick's point is a valid one. Are you sure the water is leaking in and not coming from your fuel source? It certainly sounds like you've done everything possible on your end to seal the penetrations.
Steve
"Serendipity" - 2017 Sweetwater 2286 WB Tritoon w/ 150HP Yamaha
Slipped at Lake Anna, Virginia
Primary Residence: Richmond, Virgina
Lake House: Lake Anna, Virginia

bkvanbek
Posts: 7
Joined: Fri Jul 14, 2017 8:02 pm

Re: Getting water in fuel tank

#4 Post by bkvanbek » Thu Jul 29, 2021 5:27 am

Of course water could come from the gas source. But I believe that is less likely because I only got it from gas stations, no dock gas or gas cans. Also the fuel intake fitting looks suspicious, but I don't know how it should look.

User avatar
Rick McC.
Posts: 419
Joined: Fri Mar 31, 2017 7:12 pm
Location: Weeki Wachee, Fl

Re: Getting water in fuel tank

#5 Post by Rick McC. » Fri Jul 30, 2021 2:23 pm

bkvanbek wrote:
Thu Jul 29, 2021 5:27 am
Of course water could come from the gas source. But I believe that is less likely because I only got it from gas stations, no dock gas or gas cans. Also the fuel intake fitting looks suspicious, but I don't know how it should look.
The worst fuel/water problem I ever had (actually the only one) came from a local gas station; from their pump right into my boat tank.
Rick

Sights are for the unenlightened.

bkvanbek
Posts: 7
Joined: Fri Jul 14, 2017 8:02 pm

Re: Getting water in fuel tank

#6 Post by bkvanbek » Sat Jul 31, 2021 6:01 am

I am curious how you know the water came from a gas station. But really what I am trying to find out is how the fuel fitting, at the tank, for the line to the engine is suppose to be waterproofed.

Steiner
Posts: 390
Joined: Thu Aug 01, 2019 7:51 am
Location: Lyman, SC

Re: Getting water in fuel tank

#7 Post by Steiner » Sat Jul 31, 2021 5:43 pm

Bulkhead fitting should have a nylon washer top and bottom. I did a fuel return on an old car tank like that when installing fuel injection. It's below the fuel level on the side of the tank and never leaked. It had a shoulder on it and only used a nut on the bottom though. If they used a fitting with no shoulder and a nut then the threads are a leak path even if it had a rubber or other sealing washer under the nut. If there's nothing under the nut it's even worse.
https://flic.kr/p/aqJpQY

Image
2019 G3 SunCatcher V322 SS tritoon, Yamaha F200
2019 F-150 XLT SuperCrew FX4, 3.5L EcoBoost Max Trailer Tow Package

User avatar
Rick McC.
Posts: 419
Joined: Fri Mar 31, 2017 7:12 pm
Location: Weeki Wachee, Fl

Re: Getting water in fuel tank

#8 Post by Rick McC. » Mon Aug 02, 2021 7:25 pm

bkvanbek wrote:
Sat Jul 31, 2021 6:01 am
I am curious how you know the water came from a gas station. But really what I am trying to find out is how the fuel fitting, at the tank, for the line to the engine is suppose to be waterproofed.
Well; there were a few clues.

1. The new boat ran fine before I gassed up there; but was messed up after. I believe that about seven gallons of water were ultimately removed from the boat tank; which is a good bit more than one would ever get from condensation.
2. Right after I bought the gas; they closed it down, and had some multi-point pumps running throughout the property for several weeks attempting to alleviate the groundwater contamination from the old leaking tanks.

I’ll hazard a guess that, when the seasonal groundwater table was high; water got into the tanks. During the dry season, when the potentiometric surface of the groundwater was low; the gasoline leaked out of the tanks into the surrounding soils, and had been doing so for many years.
Rick

Sights are for the unenlightened.

Post Reply