water in Outboard fuel tank

[Sandro]

Old timers were more sensible than we are.
In old motorbike tanks the fuel tap inlet inside the tank was not level with the bottom but 1/2 or 1 " higher. Possible water stayed on the bottom and could not be lead to the carburator.
It worked.
I had a personal someway unseemly experience when 16 or 17 y. o. (about 60 years ago) with my Guzzino (a Moto Guzzi 65 c.c. lightweight motor bike. A wonderful little engine).
After a holyday time football match amongst my school fellows, I was leaving for a 50 km return trip to my country village. When I mounted on the bike I noticed all my friends surrounding and gazing at me. I expected a trick but I started the motor, engaged first gear and left regularly. I made the trip and used the bike the whole summer long.
In autumn, on meeting my school fellows again they asked: "How was your trip home?" "Good." I said. They went laughing to one of them and said him: "If so, next time I have to tank I'll ask you."
He had peed in the Guzzino tank!
They had let me leave, with rain approaching, expecting me to be stopped after a few hundred metres. Things you do at that age.
Immediate tank inspection revealed a large rusty "water" bubble rolling around the flat bottom of the tank but not reaching the high tap inlet.
Sandro

 

[thinwater]

This is well known in the US. The EPA was well aware of the problem for boaters when they introduced E10.

In a nutshell, if the gas contains more than about 0.4% water, particularly if the temperature drops, the water and ALL of the ethanol fall out, creating a bottom layer that is ~ 90% ethanol and either doesn't run or runs very crappy with choke mostly on. It is also quite corrosive to metals, will pit the carb bowl, and the the oxides from the corrosion will clog jets. Additionally, the deposits are not organic (they are aluminum corrosion products) and are not dissolved by carb cleaners.

The solution?
- avoid filler leaks
- add a vent drier if you have an inboard tank (H2out.com)(http://www.h2out.com/#!air-vent-dryers/c1mor)
- use an anti-corrosion additive. Startron (Soltron?) has tested well in the US, as have products from Merc and Bio-bor (Biobor EB).

http://tanknology.com/pdf/Ethanol-Prep-EPA-Water-Phase-Separation-in-Oxy-Gas.pdf

 

[Billows]

Check the container you decant the fuel from.Could be water in that maybe.

 

[thinwater]

^^How? I hear that a lot, but it's not actually that simple if the container is full.

 

[RichardS]

^^How? I hear that a lot, but it's not actually that simple if the container is full.

If the container is full and sealed properly it would have to be water which was aleady present in the fuel supply at the fuel retailer the container was filled.

Richard

 

[thinwater]

^^ My wording was ambiguous. No, I seriously doubt any seller has free water in his fuel (though there may be some dissolved water). What I meant was how do you check for water?

I spent 35 years in the refining business, so I know how to check. But how to do it easily in a full can, without special tools, is not so obvious to me.

Explain.

 

[cleatsandcode]

I've been working away on this problem and come up with a little after market adaption to the fuel breather and works nicely. let me know your thoughts on it!
thetanktop.co.uk