Mercruiser 5.0L winter water in gas tank - Help Please

[FabienLamour]

Crownline 21ss 2007

How can I eliminate water in my gas thank. There is quite a bit of it, the new water filter had 1/8 or less when i replaced it today.

thanks

 

[Bondo]

Ayuh,.... Welcome Aboard,.... The water will be under the gasoline, so pump it out, from the bottom of the tank,.....

When it turns from water, to gasoline, stop pumpin',....

It'll probably take a couple of filter changes to get the last little bit of water,.....

 

[alldodge]

Did it just leak in or has it been there over the winter?
What does the gas look like when the filter is emptied in a clear baggy or container?

 

[FabienLamour]

No idea what happened. Last September boat was runnning fine while gas tank was full of fresh gas. Winterized it and stored in garage always. Up in Canada cold winters. Now i have been having issues non stop,,, changed sparks, rotor, wires, idle speed control motor,,,,now water in my gas? Still strored in garage...just replaced the new water filter from last October and a few tea spoons of water in filter.

 

[Rick Stephens]

On some boats you can gain access to the fuel gauge sender.. Removing it will let you shine a light in and see the bottom of the tank. Makes it easy to see if there is a lot or a little water on the bottom.

You hear people talk about phase separation of ethanol fuels when they get water in them. With all your other symptoms and subsequent repairs, you might consider whether that may have happened. What phase separation is is when water is introduced to a fuel with ethanol, the ethanol and water are molecularly attracted and combine together, pulling the now heavier ethanol water mix to the bottom of your tank. Ethanol is added to the fuel as a way to add octane booster. Since the ethanol is somewhere around 10-15 points of your octane, when you mix it with water it separates out and pulls that amount of octane out of the remainder of your fuel. So the bulk of the fuel now has less octane than your engine needs to run. Remedy is usually to pump it out and replace with clean fuel. You can burn this fuel in lawn mower and other garden type engines.

Ethanol is highly hygroscopic. If the air around the fuel has a lot of moisture in it, the ethanol will suck it in and destroy the fuel. Most common solution is to make sure you store with the tank full which limits the amount of surface to contact air.