Sour fuel question

[sogood]

As part of the overhaul of my Wellcraft, I've had to remove about 80 gallons of old fuel from the tank. Still some more to remove, but then I'll need to clean/ flush the tank and fuel lines. The carb has been rebuilt by the previous owner and the boat was "test run" using a portable tank.
​So, what's the best way to get everything clean again?
I'm based in Ireland, so American product trade names might not mean a lot to me. I'm more interested in what type of cleaning products are recommended and the best procedure to use.
Needless to say, new fuel filter and water separator are on the shopping list. FWIW the boat is fitted with a Mercruiser 5.7.
Thanks in advance.

 

[Scott Danforth]

if you just need to clean crap from the tank, a good lacquer thinner has always worked for me on metal tanks. just make sure it is drained. there are water based chemicals out there for cleaning fuel tanks. your local radiator shop may know of something.

if you want to flush the fuel lines, the lacquer thinner will not harm the metal lines. not sure on the rubber lines.

use the water based chemicals on plastic tanks, etc.

 

[redneck joe]

Can ypu remove the tank?

 

[sogood]

Thanks for the responses. The tank is aluminium from what I can see and it is removable, in that, a section of the deck is removable, exposing the tank. However, it is embedded in an expandable foam type of material. So a lot of cutting and chopping might be needed to free it. Then there's the issue of replacing the foam when refitting the tank. So, if possible, I'd rather not have to remove it.
​I'm sure it would make the cleaning/flushing/draining easier with the tank out, but if there's an easier way..........................

 

[Scott Danforth]

pulling the fuel sender will allow access to the inside of the tank. if there are no baffles, a good soap mixture and a pressure washer will do wonders.

 

[airshot]

Water white (clear) kerosene works well also and is less flammable/volatile than other solvents. Also safe for metal and rubber hoses. With some serious sloshing around it will pick up water residue if you pump it out quickly after sloshing it around, and any small amount left over will mix with the gasoline without a problem

 

[sogood]

I've already had the sender unit off to pump out (most of) the old fuel, still some left to go. So you're saying a detergent mix followed by a power wash? Will that get into all the corners or would most of any lacquer/crud etc. be sitting on the bottom of the tank? Thanks for the responses.

 

[frantically relaxing]

Unless there's sand or other dirt in the tank, I wouldn't mess with it, just let a new tank of gas do the work... add new fuel and filters, and replace the filters after you burn thru the first tank of gas. After that you should be good to go...

and don't bother with cleaning your fuel lines, replace them. Cheap insurance.

 

[sogood]

Many thanks for that. I had been harbouring such a notion and it seems to be the way to go. New filters are on the shopping list along with a water separator or two.
​Thanks again.