Bad Fuel Remedies?

[Capn Skippy]

Hi all,

Our new to us (gasoline) gem (she's still unnamed as yet) had fuel that was up to 3 yrs old - full tanks!!

The mechanic thought it was okay to burn it until we used near all of it up-suggesting we didn't refuel until that happened. Local fuel supplier for our club fuel dock had similar advice as long as it had been treated.

Difference between the 2 was where to fill up again, and is why I'm posting. Mechanic wanted it all burned saying new fuel would just end up contaminated rather than making old gas better. Fuel company said don't go to less than 10% and even that they said was probably less than they'd recommend... more harm done to fuel pump and injectors if we "ran it dry!"

What say the esteemed sages here?

Thanks for any input anyone might share!

Mark

 

[Comodave]

It depends what gas was in the tanks. If it is E10 then it is bad and should be pumped out, IMO. If it was rec gas then just run it. We have rec gas at our marina and I have used rec gas that was 4 years old without any problems. Rec gas doesn’t have any ethanol in it so it doesn’t phase seperate. If it is E-10 then it will have phase separated long ago and you may be pumping water into the engine. I had a boat that had E-10 in it when we moved to Michigan. When we lived in Arizona the boat never was laid up for the winter so E-10 wasn’t a problem. Then we moved to Michigan and were going to lay it up for the winter so we had the tank pumped out and filled it with rec gas. So you need to determine what gas is in the tank. Good luck.

 

[boatpoker]

Confused

You say it's gasoline and then you refer to injectors ?
So what is it, gasoline or diesel ?

If it's gasoline, running out of gas won't hurt a thing. Add some gas and start her up.... may have to crank a little to get the fuel from the pump to the carb. On the other hand if it's got ethanol in the gas it may have phase separated and you could end up running water through your carb and into your cylinders and that won't be nice. I wouldn't run 3yr old gas through my engine at all unless I knew for sure there was no ethanol in it.

If it's diesel and you run out of fuel you'll have to bleed the engine and this won't hurt anything either.

 

[Capn Skippy]

I'm not familiar with the term "rec gas" however ours is non-ethanol premium unleaded... I suspect they are near to or identically the same. I have run 2/3 of a tank thru on an extended shake down cruise... seemed fine, but now that weather's changed-or maybe crud in bottom of tank?-it's running a bit rough and idle is challenged.

 

[boatpoker]

It depends what gas was in the tanks. If it is E10 then it is bad and should be pumped out, IMO. If it was rec gas then just run it. We have rec gas at our marina and I have used rec gas that was 4 years old without any problems. Rec gas doesn’t have any ethanol in it so it doesn’t phase seperate. If it is E-10 then it will have phase separated long ago and you may be pumping water into the engine. I had a boat that had E-10 in it when we moved to Michigan. When we lived in Arizona the boat never was laid up for the winter so E-10 wasn’t a problem. Then we moved to Michigan and were going to lay it up for the winter so we had the tank pumped out and filled it with rec gas. So you need to determine what gas is in the tank. Good luck.

Beat me to it You posted while I was typing

 

[Capn Skippy]

Boatpoker - is fuel injected, as in not carbed... Crusader 350xli engines. But yes it is gasoline.

 

[Comodave]

Rec gas is recreational gas for boats and off road vehicles. It doesn’t have E-10 in it. Ours is good for at least 5 years. We bought a boat that was bone dry, filled it with rec gas and it sat for 4 years while we worked on it and moved to Michigan. It ran fine though I did add fuel conditioner every year. Now if you have crud in the tank you should stock up on filter elements.

 

[C lectric]

Ask your mechanic about testing kits. Maybe not for gas but ask. That should answer whether or not you have Ethanol laced fuel.

Most labs will test diesel, coolant, engine oil, hydraulic oils and so on. SO ask about gas. The shipping ,may be the problem.

 

[Capn Skippy]

Ask your mechanic about testing kits. Maybe not for gas but ask. That should answer whether or not you have Ethanol laced fuel.

Most labs will test diesel, coolant, engine oil, hydraulic oils and so on. SO ask about gas. The shipping ,may be the problem.

Our fuel is unleaded premium non-ethanol... Just changed in line fuel filter and water separator yesterday and will fill tanks tomorrow using some stabilizer just in case for the remaining old fuel.

 

[Comodave]

Our fuel is unleaded premium non-ethanol... Just changed in line fuel filter and water separator yesterday and will fill tanks tomorrow using some stabilizer just in case for the remaining old fuel.

With that fuel and some stabilizer you should be good to go.

 

[FF]

There are pastes that can be shmered on a stick or the end of a tape measure that will change color with water. Dip the tank.

If the color sez fuel not water the fuel can be burned , BUT will have probably lost the aromatics , the stuff that keeps it from preigniting (knocking) under heavy load.

So burn it up at half throttle or so , no towing water skiers.

 

[High Wire]

When e10 phase separates, the water settles on the tank bottom. That water is the first to get sucked out of the tank pickup. If you have already gotten through 2/3 of all fuel tanks then any water is gone into the water separating fuel filters. Change out those filters and fill up with fresh gas.

 

[PM]

It doesn't matter. Do whatever is convenient. Three year old gasoline is not "over the edge". If it still burns, burn it up.

My Grandfather had an old model "T" that he would fire up every year or so. He was proud of saying that there was still some of the original gas in the tank. 50 or 80 years old. Of course it had been diluted down thousands of times and the "original" aspect of it was probably about a drop in ten gallons but he was right. It still had some original gas in the tank.

pete

 

[RickyD]

You could do what I did with my ski boat that I did not run for 5 years. I pumped it out by tapping into the fuel line that goes into the fuel filter. I pumped it into smaller containers and little by little I burned it in my cars thereby adding lets say 5 gallons of old fuel to 15 gallons of good fuel and burned in a car designed to run E-10. Worked fine. Ok I know 35 gallons is different than 350 gallons.

 

[bayview]

Do not add new gas to the old until the tank is very low otherwise you will be running some old gas for a long time.

Also even if you add octane improved I would not run the engines at more than low load to avoid knocking and burning the valves and pistons. Take it slow and have fun. Wait for later to try speed runs.

 

[wkearney99]

Do not add new gas to the old until the tank is very low otherwise you will be running some old gas for a long time.

This.

With a previous boat we had a season that had a lot of service-related interruptions, leading to a lot of time where the boat sat and the fuel went bad. Not bad enough to be really obvious, just poor running. Eventually though, it was clear that the gas was bad. It wouldn't keep a stable idle, had no top end power and was a bit hard to start. I tried running it nearly empty before refilling and that only partially solved it. Full top-end power just wasn't there.

The solution was, finally, having the fuel removed entirely. Once that was done, along with new filters, the problems stopped.

So you can either chase your tail and eventually have to remove the fuel, or just remove it now. My advice would be remove it all, replace the filters (preferably ones with a sight glass and drain for water) and run a small amount of fresh fuel. Make sure it's running it's best, and that you're not seeing water in the separator. Once you're sure it's running right, top up the fuel and have fun.

 

[Hippocampus]

Not considered is the tank. Worse case is everything is fine until you have a bumpy day. Then the crud in the bottom or walls of the tank gets dislodged and your engine fails at just the wrong time putting you in danger. Would open the examination ports and get a good look see at the condition of the bottom and walls of the tank. If contamination seen pump it out (polish or refunction it) and have the tank cleaned. With gas it’s fairly unlikely for to have stuff growing in it but depending upon what type of tank and past history there may be contamination.

 

[Capn Skippy]

Just wanted to say thank you for all the great advice... In the end we chose to follow mechanics suggestions and (slightly over) dose the tanks with stabilizer - Startron - and then fill the tanks this morning. Afternoon cruise up and down the river w/highly skilled (compared to my novice skill level) friends for an afternoon get together. I'll update everyone next week on how it goes.



Again, my thanks! Great group here!

Mark