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Fuel going bad
https://slantsix.org/forum/viewtopic.php?t=64892
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Author:  rich006 [ Thu May 14, 2020 8:44 pm ]
Post subject:  Fuel going bad

I pulled my engine in February thinking it might take a couple of months or more to rebuild. But surprise, it has taken a lot longer (still at machine shop). I have a pretty full gas tank and there is (probably) still fuel in the carb. How long is too long for fuel to sit in a garaged vehicle? Do I need to do anything special to the carb other than pour out the bowl? Any tips on siphoning fuel out of the tank?

Author:  plymouthcranbrook [ Thu May 14, 2020 9:12 pm ]
Post subject:  Re: Fuel going bad

Put in the correct amount of Sta-bil fuel stabilizer for the amount of fuel in your tank. It will be fine for a year at least and one year I ended up putting more in at the end of that time and still had fuel 6 months later. Just keep the cap on tight.

Author:  Dart270 [ Fri May 15, 2020 5:46 am ]
Post subject:  Re: Fuel going bad

I never worry about this and have never noticed a problem. Just yesterday I fired up my 68 Dart after 1.5 yrs in storage. It stared like it had been run yesterday and settled into idle. The days of needing Stabil are long past, IMHO, as the additives in modern gas are far better than what they were when these cars were made.

I have also fired up racecars after 6-8 mo of storage and gone and run them at the track and seen no ill effects.

Others may disagree with me, but if it were my car I would just forget this as a problem. I might pour the gas out of the fuel bowl vent, but likely it has evaporated already.

On a related topic, I feel that "bad gas" out of the pump is also long dead history. I have never noticed any tangible difference in gas on how the car runs when I fill up, unless I change grades (87, 89, 91...). This is one of those persistent myths, like not storing/charging a battery on the floor, that just refuses to die.

Lou

Author:  matv91 [ Fri May 15, 2020 7:03 am ]
Post subject:  Phase Separation in Ethanol Blended Gasoline

https://www.boatus.com/seaworthy/SeaApr10Ethanol.pdf plug vent line to evap canister also

Author:  SlantSixDan [ Fri May 15, 2020 10:59 am ]
Post subject:  Re: Fuel going bad

Project Farm sheds some light:
https://www.youtube.com/watch?v=UvS_D4_lF5U

Author:  ProCycle [ Fri May 15, 2020 11:54 am ]
Post subject:  Re: Fuel going bad

Quote:
I never worry about this and have never noticed a problem. Just yesterday I fired up my 68 Dart after 1.5 yrs in storage. It stared like it had been run yesterday and settled into idle. The days of needing Stabil are long past, IMHO, as the additives in modern gas are far better than what they were when these cars were made.
Here in the motorcycle world my experience is exactly opposite. 3-4 weeks of sitting with fuel in the carb can produce a bike that will not start. 30 years ago it would take 6+ months to go off. Tiny pilot jets clog with the thinnest layer of varnish. Fuel in a carburetor that is well vented to atmosphere goes flat quickest. Fuel in a closed fuel tank stays good much longer. Fuel in fuel injected bikes that have little or no exposure to the atmosphere stays fresh for a very long time.

My unscientific take on this is that the light, easy to vaporize components that aid cold starting have been decreased in modern fuel to cut evaporative emissions. It now takes less time for enough light components to disappear and cause hard cold starts. I have also noticed that gas looses its 'fresh' smell much faster than it used to. When I drain fuel out of a carb that's been sitting for a month or two it has very little odor.

Author:  Dart270 [ Fri May 15, 2020 6:58 pm ]
Post subject:  Re: Fuel going bad

Far out. It is true that ethanol will absorb water and I have no problem thinking it can cause corrosion. Somehow, something I am doing is making me immune to all of this... Perhaps it is the weather here...

Lou

Author:  rich006 [ Fri May 15, 2020 7:20 pm ]
Post subject:  Re: Fuel going bad

Interesting videos. My carb seems to be empty now, so I guess any damage to it is already done. My fuel tank is pretty full (and the vapor line is plugged), so hopefully there isn't too much moisture in there.

Author:  ProCycle [ Fri May 15, 2020 7:22 pm ]
Post subject:  Re: Fuel going bad

The ethanol certainly does absorb moisture - which can be a good thing up to the point where it starts dropping out of solution.

For me personally the only real problem I run into with ethanol is it attacks certain Japanese motorcycle orings. Items commonly used in carburetors.
5 years exposure is enough to do this.

Image

Author:  SlantSixDan [ Fri May 15, 2020 7:43 pm ]
Post subject:  Re: Fuel going bad

Quote:
Far out. It is true that ethanol will absorb water and I have no problem thinking it can cause corrosion.
Water in ethanol can also prevent corrosion, believe it or don't.

Author:  emsvitil [ Fri May 15, 2020 8:04 pm ]
Post subject:  Re: Fuel going bad

Quote:
Quote:
I never worry about this and have never noticed a problem. Just yesterday I fired up my 68 Dart after 1.5 yrs in storage. It stared like it had been run yesterday and settled into idle. The days of needing Stabil are long past, IMHO, as the additives in modern gas are far better than what they were when these cars were made.
Here in the motorcycle world my experience is exactly opposite. 3-4 weeks of sitting with fuel in the carb can produce a bike that will not start. 30 years ago it would take 6+ months to go off. Tiny pilot jets clog with the thinnest layer of varnish. Fuel in a carburetor that is well vented to atmosphere goes flat quickest. Fuel in a closed fuel tank stays good much longer. Fuel in fuel injected bikes that have little or no exposure to the atmosphere stays fresh for a very long time.

My unscientific take on this is that the light, easy to vaporize components that aid cold starting have been decreased in modern fuel to cut evaporative emissions. It now takes less time for enough light components to disappear and cause hard cold starts. I have also noticed that gas looses its 'fresh' smell much faster than it used to. When I drain fuel out of a carb that's been sitting for a month or two it has very little odor.

And that's why I turn the petcock off and keep my bike running until it dies and why I added a fuel shutoff valve to my lawn mower and let it die too...……….

Author:  volaredon [ Fri May 15, 2020 9:13 pm ]
Post subject:  Re: Fuel going bad

Quote:
Far out. It is true that ethanol will absorb water and I have no problem thinking it can cause corrosion. Somehow, something I am doing is making me immune to all of this... Perhaps it is the weather here...

Lou
are you running straight gas? (non ethanol blend) that will make a difference. we have just recently been able to get straight pure 100% gas again at a few stations around here but its only available in 92 octane even at that...

I do ALOT of small gas engine stuff, well not as much as I used to, but still more than I need to.... and most "no start" or "runs bad" issues I see around here are from gas left in the machine in the offseason.... though, if the particular machine has a fuel shutoff, and it is utilized and run til the carb runs dry there are many less issues at the beginning of the next season....
though on my 78 Fury (oops 318 car) Ive left it sit 2 years a couple times in the 13 years I have had it, and haven't had any issues with that from old gas.... but I always make sure to load it up with Sta Bil, when I park it for the winter. usually it comes out this time of year, most years....

Author:  hank2 [ Fri May 15, 2020 9:42 pm ]
Post subject:  Re: Fuel going bad

Quote:
Quote:
I never worry about this and have never noticed a problem. Just yesterday I fired up my 68 Dart after 1.5 yrs in storage. It stared like it had been run yesterday and settled into idle. The days of needing Stabil are long past, IMHO, as the additives in modern gas are far better than what they were when these cars were made.
Here in the motorcycle world my experience is exactly opposite. 3-4 weeks of sitting with fuel in the carb can produce a bike that will not start. 30 years ago it would take 6+ months to go off. Tiny pilot jets clog with the thinnest layer of varnish. Fuel in a carburetor that is well vented to atmosphere goes flat quickest. Fuel in a closed fuel tank stays good much longer. Fuel in fuel injected bikes that have little or no exposure to the atmosphere stays fresh for a very long time.

My unscientific take on this is that the light, easy to vaporize components that aid cold starting have been decreased in modern fuel to cut evaporative emissions. It now takes less time for enough light components to disappear and cause hard cold starts. I have also noticed that gas looses its 'fresh' smell much faster than it used to. When I drain fuel out of a carb that's been sitting for a month or two it has very little odor.
I returned to an old carbureted Suzuki bike after some years with a FI later model. I have a couple of zero ethanol fuel stations within 10 miles and a couple more further away. It has seen nothing but the E0 fuel in my tenure. I do dose it for the Winter layup with Stabil marine, biobor or starbron stabilizer. I have seen some evidence of both E10 and E0 current degrading in 2 or 3 months. My slant truck often sees E10, but I usually dose that fuel when I think of it. I'm curious if there is still any actual difference between Winter and Summer gasoline volatility blends. I believe there still are official fuel "seasons", at least in the Northeast. Even dosed E0 fuel in my home stash of 5 or 10 gallons seems to need to be swapped out at least twice a year.

Author:  Dart270 [ Sat May 16, 2020 5:45 am ]
Post subject:  Re: Fuel going bad

I do have a no-ethanol gas station 5 min away and I tend to use that for cars and mower, although certainly not exclusively.

Lou

Author:  Rick Covalt [ Sat May 16, 2020 5:28 pm ]
Post subject:  Re: Fuel going bad

It is really funny how different people have or don't have problems using the same things. I work on small engines now every day and I see dozens of carbs every week that are gummed up, bowls full of gel, bowls rusted through from water....etc. Mostly from people allowing the engines set with old gas in them and then trying to get them to run.
On my personal stuff, I have never added stabil, I have never run them out of gas, and never run ethanol free gas, and I have yet to have a carburetor issue with anything I own. Mower, push mower, and tiller are all started in the spring with a little shot of starting fluid ( Why pull the cord more than once if you don't have to!)
Once they start I let them run and fill them with gas and go about my business for another year. I have been doing this for at least the last 12-15 years without a problem. No I don't have an answer for it either.

As for the original poster. Fire it up and run it . Add fresh gas when you can and forget it.

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