OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines weirdly dirty fuel

hi
I had a friend of mine bring me there tornado with the quantum engine to fix. they said it was running as usual then the fuel ran out so they filled it up with the last of there fuel can. it started as usual ran for say 5 minutes then died out an wouldn't restart. so I think maybe dirty fuel an blockage. so today I get stuck into it an I take the fuel tank off an I start draining it through the fuel line noozle. all that comes out is like orange water.




then that stops an nothing so I take the fuel cap off an its full of fuel so I tip that out when the fuel an the orange water met they instantly separated like a lava lamp. I have never come across this, has anyone else? an what would it be? remember this mower had used a few tanks of fuel before this an hadn't sat for a long period of time either. would it be from the fuel can or from bowser?

Nathan, I can't give you a definite answer but I can provide a few clues. First, I have throughout my life, used petrol that was quite a few years old - mostly in cars but more recently in mowers. I have also used mixed 2 stroke fuel that was up to 4 years old. In no case was the fuel discoloured, and it always worked exactly as new fuel would have. However, this is not the case if fuel containing ethanol is involved. The ethanol is hygroscopic - it absorbs moisture from the atmosphere. Then it turns into the yellow clag you found in that fuel tank.

We do not have ether added to the fuel in Australia, but the practice is widespread in the US. (The ether based additives have names such as MTBE, TAME, etc.) These fuels, which nearly always contain ethanol as well and are called "reformulated gasoline", deteriorate in much less time than ethanol alone - sometimes it happens in as little as weeks. As a result, the addition of fuel stabiliser to fuel tanks that are not emptied at the beginning of winter, is mandatory there.

So, my guess would be that the yellow mess in that tank is the result of long-term moisture contamination of a fuel that contained ethanol. I suggest you clean it out of the tank, fuel line, fuel tap, fuel filter, and carburetor, then make very sure you do not use a fuel containing ethanol in the future.

great advice as always grumpy , her in S.A i think some places have more problems with ethanol now too , seems i have been getting water in just under a week in steel containers and a tad longer in plastic now , just never EVER use the dregs .

good old thing ..... tip it in the car but still dont use the bottom of container seems the fuel now isnt antwhere near as reliable as we would like , premium is a lot better but still sometimes happens

vccomm, I'm used to petrol pumps having a sticker on them if the fuel contains ethanol. In Victoria those fuels normally sell for about 3 cents a litre less than the real stuff of the same octane. I don't buy it - not only does it cause problems eventually through fuel system damage, but it isn't economic in terms of fuel consumption. Ethanol has to be mixed with air in the ratio of one part fuel to 8 parts air. Petrol has to be mixed with air in the ratio of one part fuel to 14 parts air. Consequently the oxygen sensor makes the mixture richer when there is ethanol in the fuel. By my calculations, to break even in fuel consumption per dollar, fuel containing 10% ethanol needs to be 4.5% cheaper than the real stuff. 3 cents per litre price difference, at $1.50 per litre, is only 2% cheaper. And that is before you consider the cost of early replacement of fuel system components. Essentially, I think people who buy or tolerate the stuff haven't thought it through.