water in fuel

[lateralinfo]

the fuel i use is supposed to be of top quality. i had left my boat sitting in the water for almost a month without turning it one with the fuel tank filled to 90%.
when i took it for its first trip, i had a "water in fuel" alarm multiple times in the starboard engine. every time i would empty both the water separator and the filter. 10-15 minutes later, same alarm.
when i got back to the marina, i opened the fuel tank through the fuel sensor, ran a hose to the bottom of the tank, and siphoned out roughly 10L of fuel. there was a couple of inches of water in the bottom. but then that was it, no more water came out.
the water separator were rusted (both of them) and filled with pieces of depbris (rust and other stuff), so Suzuki recommended changing them.
after that, i took the boat for a sea trial, all is going well. however, i still found a couple of drops of water in the water separators and they both are already starting to rust on the inside. also, some minor traces of dirt was found
so, i have some questions:
1- could this be due to water condensation in side the tank cause i didnt winterize the fuel tank with additives (temperature is around 10-15 degrees celsius) or should i suspect a leak in the tank?
2- how can i avoid this situation in the future?
3- should i worry about the quality of the fuel remaining in the tank? should i simply dump it?
4- my plan is to use the remainder of the fuel, and once empty i would clean the tank. any tips on how to clean the tank properly while the boat is still in the water?

[Harper]

Is your tank metal or plastic? Those temperatures don't seem cold enough to cause any condesation problem, especially if it's a plastic tank. The cool temps might foster condensation in a metal tank, but that seems like an awful lot of water for just a condensation problem. So I would suspect some other way that the water is getting in. Any rain during that period?

[lateralinfo]

yes it rains a lot and i cleaned the boat several times. the tank is built in the boat so i am not sure since its covered with fiber but i think it a metal tank.

[Moonlighter]

There are 4 main ways for water to get into a fuel tank

1. When the fuel is contaminated with water at the gas station. You can test this by using a special water filtering funnel - here they are called “Mr Funnel”. Getbthe large sized one and use it to filter the first 10 litres ypu put into the tank at the gas station, if you see any sign of water, you now know the source! Time for harsh words with the gas staion management.

https://www.mrfunnelaustralia.com.au...formation.html

2. Thru the gas tank filler cap - eg the seal on the gas tank cap is damaged, or the cap wasnt put on properly.

3. Water is getting in thru the tank”s breather hose when the boat is underway, seen this a few times where the breather outlet was badly positioned or angled forwards, and in certain sea conditions, water was forced into the breather outlet as the boat cuts thru waves, and thus went into the tank.

Or, some idiot was washing down the boat with a hose and sprayed water directly up the breather outlet!

Solution? Reposition the breather outlet to a better position, or shield it so it is impossible for water to get into it. Or, kick the person who washed the boat in the butt!

4, thru the fuel tank sender unit fitting. If water can get onto the top of the tank thru a insoecion hatch etc, then the sender unit filling is usually the lowest area and water can pool there and gradually seep into the tank if the sender unit gaskets etc are not in tip top ocndition. Solution is to replace the sender unit gasket, and fix the hatch to prevent water getting onto the tank.

So you can check all of those things and see if you can eliminate them one by one from being the problem.

[Solarman]

There is a phase separation of ethanol that turns to water, and leaves an orange/rust colored substance too. Are you sure the fuel you're buying is not ethanol?

Good luck.

[Murray]

I would not use the remaining fuel in your outboard. If the fuel has separated from old age chances are it will not be clear but rather the colour of an amber ale.

[lateralinfo]

actually, the water from the fuel separators have an orange hue, and has a weird substance in it. but when i pumped some more fuel from the outlet hose, the fuel color seems ok with only a few drops of water on the bottom (attached pic).
the new water separators are starting to rust.
do you recommend getting rid of the fuel and changing the water separators? WhatsApp Image 2019-03-25 at 11.44.42.jpegWhatsApp Image 2019-03-25 at 14.28.10.jpeg

[Murray]

That amber colour isn’t what fresh fuel should look like. Fresh fuel will be clear, no colour.