Longetivity of Gas in Tank

[Kaizer]

I was wondering, what are the consequences of keeping the same tank of gas (WITH SEA FOAM Added) in the bike for over a month or longer. What will happen? I let gas sit in her for a while since I don't ride too much or too long. Let me know. Thanks!

[Merritt]

Dunno what sea foam is, never used it.

I do however, pour some fuel stabilizer in my tank in late fall/ early winter.  Gasoline can start to to gum up and varnish in as little as 60 days.  Fuel stabilizer will keep it from going 'stale' for up to two years (no guarantees).  A little stabilizer in your tank at the beginning of winter (and when you refill), will keep it from going bad.  My bike fires right up.

[daliumong]

agree on the fuel stabilizer. its a good thing to have, relatively cheap too, only like 5 bucks is enough to treat an entire tank maybe 5 times over

[platinum_black]

if i am right sea foam is a form of stabilizer so you should be fine, as it was created primarily for the fishing industry to stop the fuel going stale and to also prevent varnish and carbon problems.

[jrains89]

yea seafoam is a stabilizer as well as a bunch of other awesome things. you'll be fine.

[grayghost]

used to be in the refining business, and the 3 main problem areas of "old" fuel:
  (1) condensation in tank
  (2) potential problems from existant gum (usually related to chemical structure of the charge stock at the time of fractionation)
  (3) if exposed to high temps (90-100+F) lighter end components of gas may evaporate leaving a significantly different residual fuel from
       a vapor pressure/possible lower octane standpoint.
#3 can really pose a problem with 2 strokes where the oil/fuel mix is actually done in the tank VS an injection method.

i don't use any fuel (whether stabilized or not) past 90 days (mostly due to a chance for condensation in my neck of the woods)- may not
make any difference, but at that point i'll drain it off to use in a fill up on the mower or such.

[simon79]

My personal experience -

I fired up my bike a couple weeks ago after letting it sit since last October.
There was - and still is - 0.5 to 1 gal of non-stabilized 98-octane gasoline in the tank, and I had kept carb float bowls and fuel lines - at least the two tubes going from tank to carbs - empty to avoid fuel gumming up in there.
The engine started up almost immediately, no smoke, no sputtering as far as I can recall.
On a side note, my bike is stored into a garage, sheltered enough from water, cold and humidity.

Maybe I've just been lucky, but that's it.
I'd probably worry about fuel staying there for several months and/or in a poor storing condition (IMHO).

Cheers

[ivany]

I let my bike sit for about 6 months with no prep (can't really remember, sold it to a friend who didn't ride it).

It had a new battery in it when I gave it up and when I bought it back about six months it fired up after a few cranks. It ran kind of crap for the first 50-100 miles but once I got a tank though it it was mostly back to it's old self.

Just my experience. Don't think that if you let your bike sit for more than 17 hours without stabilizer, draining carbs, etc then it'll never run again...

[theUBS]

Just don't forget that a stabilized tank of fuel might not do you any good if you didn't run the same stabilized fuel through your carbs before you parked it! 

[Kaizer]

Sounds good. For those that have used Sea Foam, how MUCH do you put in there for a full tank? I use 5 capfuls for my 5.3 gal tank. Thanks.

[bill14224]

I use Sta-Bil. Two ounces is enough for 5 gallons, and of course run it a few minutes so the gas in the bowls is treated.  I learned my lesson about 25 years ago.  Parked my Seca with no prep from Thanksgiving until about Vanentine's Day.  Bike ran like crap.  4 carbs full of varnish.    2 ounces of Sta-Bil and it never happened again.    I like easy.  Stabilizer is easy.

[pwostrel]

Seafoam is great stuff I like it better than regular fuel stabilizer, you should be just fine with the seafoam. Good luck!

PW

[theUBS]

I use Sta-Bil. Two ounces is enough for 5 gallons, and of course run it a few minutes so the gas in the bowls is treated.  I learned my lesson about 25 years ago.  Parked my Seca with no prep from Thanksgiving until about Vanentine's Day.  Bike ran like crap.  4 carbs full of varnish.    2 ounces of Sta-Bil and it never happened again.    I like easy.  Stabilizer is easy.

Sometimes I'm really glad the GS is a simple machine with 2 cylinders and 2 carbs!  If I ever own a 4-cylinder bike, may it be fuel injected!!

I started last season (when I purchased my GS) with goofy carb issues , so I was pretty adamant about using the Sta-bil before I parked it.  My buddy and I both used it in our GS's at the beginning of winter and they both fire and idle smooth now!  Money well spent!

[wladziu]

Stabil: naptha and isopropyl (and dye, of course)
Seafoam: naptha, isopropyl, and pale oil.

The isopropyl is hydrophilic.  I guess you could say that it helps the gas "absorb water".  
The pale oil is a naptha derivative, therefore has a lower flash point than gasoline and high solvency.  Like naptha, it's highly hydrogenated.  

So, basically, it helps stabilize fuel.  There.
The cause of fuel varnish is still being researched.  The best guesses are a hydrolytic reaction, thermogenic shock, different forms of catalysis, and a few other things.  Hydrolysis occurring as the unstable aromatic fuel compounds try to oxidize (however slowly) by breaking water apart to find obtain oxygen.  The resultant oxidized compounds form as sticky sediment, which is also acidic to metal surfaces.  The high hydrogen levels in naptha and pale oil (I suppose) lend molecular stability, slowing (but not stopping) the hydrolysis reaction.  

Or, perhaps the hydrogenated naptha/pale oil binds with h-bonds with water.  Together with the isopropyl, hydrolysis is prevented altogether.  
Either way.  
Or, maybe I'm way off.  I'm not a fan of orgo, anyway.  

Shell and other companies do a lot of research in this area.  They've tried additives over the years.  Modern fuel is much more stable than the stuff 25 years ago.  Any volatile aromatic wants to oxidize, even Sta-bil.  It's just a matter of how quickly.  But, I'm not sure how the allowable 10% alcohol addition effects varnishing, in the face of all those additives.  
I used to want to work for them, until I became educated on their global immorality.  

My point is:
A $3 bottle of magic is easy insurance.  
But, if you're just wanting to get rid of condensated water, just buy pure isopropyl from the hardware store.

My personal opinion is that it lowers the volatility of the fuel too much to constantly use it.  Not by much, but I still don't like it.  It works well as a solvent for one time use, and to break up carbon deposits on valves.  Old folks used to do the same thing by pouring in a few ml of water into the intake, though it doesn't do anything for the carb.  

[Kaizer]

Ok, can I use both sta-bil AND sea foam or just stick with sea foam? I forgot to mention that my tank has also been lined and treated by the radiator place two years ago. It has a red lining that seems to be giving my gas a darker color. Not sure if that is a good sign. Hmmm.

[theUBS]

Stabil: naptha and isopropyl (and dye, of course)
Seafoam: naptha, isopropyl, and pale oil.

The isopropyl is hydrophilic.  I guess you could say that it helps the gas "absorb water".  
The pale oil is a naptha derivative, therefore has a lower flash point than gasoline and high solvency.  Like naptha, it's highly hydrogenated.  

So, basically, it helps stabilize fuel.  There.
The cause of fuel varnish is still being researched.  The best guesses are a hydrolytic reaction, thermogenic shock, different forms of catalysis, and a few other things.  Hydrolysis occurring as the unstable aromatic fuel compounds try to oxidize (however slowly) by breaking water apart to find obtain oxygen.  The resultant oxidized compounds form as sticky sediment, which is also acidic to metal surfaces.  The high hydrogen levels in naptha and pale oil (I suppose) lend molecular stability, slowing (but not stopping) the hydrolysis reaction.  

Or, perhaps the hydrogenated naptha/pale oil binds with h-bonds with water.  Together with the isopropyl, hydrolysis is prevented altogether.  
Either way.  
Or, maybe I'm way off.  I'm not a fan of orgo, anyway.  

Shell and other companies do a lot of research in this area.  They've tried additives over the years.  Modern fuel is much more stable than the stuff 25 years ago.  Any volatile aromatic wants to oxidize, even Sta-bil.  It's just a matter of how quickly.  But, I'm not sure how the allowable 10% alcohol addition effects varnishing, in the face of all those additives.  
I used to want to work for them, until I became educated on their global immorality.  

My point is:
A $3 bottle of magic is easy insurance.  
But, if you're just wanting to get rid of condensated water, just buy pure isopropyl from the hardware store.

My personal opinion is that it lowers the volatility of the fuel too much to constantly use it.  Not by much, but I still don't like it.  It works well as a solvent for one time use, and to break up carbon deposits on valves.  Old folks used to do the same thing by pouring in a few ml of water into the intake, though it doesn't do anything for the carb.  

Thanks for the info.  My only concern--it worked.  I'm painlessly buring off last season's gas! =]

[wladziu]

You can use both, but it's not gonna increase effectiveness.
It's the difference between 1% milk and 2%.  Just get whichever's cheaper for the volume. 

Sta-bil is stored in a plastic bottle and has dye, which may contribute to the flakes in the bottle when it's old.  Oxidized hydrocarbon attracted to the dye, in my opinion. 
The Seafoam's can is probably coated in plastic, also, but it doesn't let UV light through. 
Just a product storage issue, though.  Find a store that sells crates of it, and hope that you don't get an old batch from the warehouse. 





I just don't like buying into the mass marketing.  OMG!!1Stabil!!!wtfTEHgreatest!!Seafoam!1Rar! FTW     It's just freakin' isopropyl and kerosene/lighter fluid. 

If it didn't lower the volatility (ability to produce energy) of gasoline, then it would be added at the distillery.  Just wanted to point that out.  Some people like to argue about it. 





The red tinge is the gas acting as a solvent on the epoxy (and it's colorant) probably used to coat the tank. 
Basically:  Epoxy has oxygen, the gas wants the oxygen.  It breaks apart the epoxy to get it.  A strong resin will resist it, though. 
I don't have much experience with this type of thing.  It might decrease after a while, but it's not gonna completely stop. 
I'm too lazy right now to figure out how that might affect varnishing on the engine components. 


If you want to figure it out yourself, then Shell might pay you eleventy billion dollars. 
Something like this:
http://www.freepatentsonline.com/4485244.html

[Kaizer]

Nice!  I could use trillions of dollars! Already busy with my research though so it will have to wait. I figured the gas would be reacting with the coating inside the tank. I just hope it won't do long term harm.

[wladziu]

Oh, yeah.  The engine.  I dunno!  I just like chemistry. 


I have no idea if it will settle out of solution and varnish the carb bowls even worse. 
I have the same problem with the fancy blue fuel hoses the previous idiot installed. 

Wish I could tell you, but I'm not up to par on my organic chem stuff, yet.  Guess you'll have to just wait and see. 
Let us know if it causes a problem.  Seriously!  Don't forget!  I want to know.