I often wonder about these "additives".

My one tractor dealer used to pick up free and do service in the late fall/early winter. He always added stabilizer. Then he sold the dealership and I only took it to the new dealer once (jerk!). After I stopped taking it for service, I never added stabilizer and have never had any problems starting and being in business in the spring.

The one outfit that I used to do aircraft work for, used Microlon in their aircraft engines. This stuff, with Teflon, was developed to keep rifle barrels cool. Then they came up with engine additives. While it's still available, even for small engines, I'm afraid of it. Some of the A/C mechanics were using the Microlon in their vehicles. I even used it in the Harley. But, one of the guys pulled the oil pan of his vehicle and found that the Microlon had turned into a cake in the bottom of the pan. That was 20 years ago, and it's still available. ?? They sure have a great story.

Does any of this stuff do, what's it's supposed to? Or is it more harmful?

Here is a link that might be useful: Microlon small engine

So what can you add to sta-bil to prolong its shelf life, synthetic Sta-bil?

The "Mistery" oil AKA MMO.

Hercules,
Thanks for posting that. I have about 8 ounces remaining in my 1.5 year old bottle I use in my generator and pressure washer. That's not something I ever thought about--the stabilizer becoming unstable.
So the bottle says it keeps gas good for 12 months. What happens after that? Does it just start to varnish and gum up the carb like unstabilized gas or do the red flakes start to appear?
Does diesel last longer thean gasoline? When I was in Iraq we ran some all-fuel deuce-and-a-halfs on Saddam's stock of jet fuel at Al Asad. I'm pretty sure it was at least a decade old, and the trucks ran fine.

remoser---Ahh!!--MMO, so few people know of it and what a great product it is...add it to your oil or your gas in the recommended amount and it surely is a Marvel what that oil clears up..cleans injector, carbs, etc...when I first found out about it, the yr 1975 it got me ten thousand more miles on my slant six(225), and extended me another 23000 before I had to do a valve job...I use it now in my bike, truck and car...the JD gets a dose next week...good stuff...

Marineguy:

I have a couple of small engines that I run infrequently, and a separate gas can for them. That fuel has stayed "fresh" with Sta-Bil for as long as 16-18 months..at least it smells fresh and still runs well in these engines.

What I was referring to was the Sta-Bil product itself...still in the bottle. Apparently something in the chemical makeup of Sta-Bil begins to crystallize and form these flakes somewhere between the 2 and 3 year point AFTER the bottle is opened....thus the warning on the label that the product is OK for up to 2 years after first opening. Once mixed with fuel, I've never had a problem (that I'm aware of).

Sorry, I have no experience with diesel powered equipment and diesel fuel stability, but todays gas formulation will allow it to "go bad" in a matter of months if untreated.

Hal

Does Sta-bil work? who knows?

I have a walkbehind snowblower, which this past winter in the end of Jan 07 I got (had) to use it, I realized as I went to start it, that it had I had accidently left the gas turned on, and the carb had sat since last season with gas in it, yes it was "old" gas, I primed it, pulled the starter, and on the second pull it fired right up and ran just fine! The old gas was over a year old, and didn't seem to make a difference to the snowblower, I did not use any treatment or additive in the gas.

Could it be that the more "modern" gas does not go "bad" or "stale" like it use too?, (and it is all hype to sell additives) And also does it not foul up, or varnish the carb if accidently left in the carb for a year?

Shawn

I think a lot depends on the local gas and it's additives. Also think the engine has a lot to do with it. I use both MMO and Stabil. I have a procedure for getting gas in my cans. Always follow it. I put Stabil in before filling them up (even my 2 stroke gas). I run MMO through when the seasons change in New England.

-gh

I use Sta-Bil in all my small engines , in fact my Honda pressure washer had a bottle along with the Honda owners manual. Some people say that SeaFoam is a better product but I never tried it myself. I have 2 bottles of Sta-Bil in garage and I know one is well over a year old....but I always check it for "flakes" before I use it. Has anyone here used SeaFoam ?.

Duke,
My Honda/Karcher pressure washer also came with a Sta-bil sample. Also it mentions in the manual to use a stabilizer. As far as conspiracy theories go, I don't think Honda will benefit from the sale of Sta-bil.
For the generator and pressure washer (and push mower that sits in my shed as a backup), I always turn off the fuel and run the carb dry before storage, on top of using stabilizer. Never had any problems.

Here is some very good information concerning shelf life of gasoline. It comes straight from the horse's mouth.

Here is a link that might be useful: Long term gasoline storage

grumpy,

I found this to be interesting in your link

"This section applies to outboard motors, jet skis, snowmobiles, and lawn-and-garden equipment.

The ownerÂs manuals of much small-engine equipment recommend that the gasoline be less than 30 days old. They also recommend that the equipment not be stored with gasoline in the fuel tank. The tank should be emptied and the equipment run until the fuel line and carburetor also are empty. Both recommendations are intended to protect essential fuel system parts from gum deposits. While Chevron gasoline is stable for much longer than 30 days, it is ChevronÂs policy to defer to the recommendations of the equipment manufacturer."

-gh

Marineguy: Diesel fuel (#2 Fuel oil) and the genre (including the range of JPs) are "light oils" and as such do not break down or "destabilize" as quickly as Volatile Organic Compounds (VOC). The temperature of the storage vessel, whether the storage vessel has freedom of exchange with outside atmoshere (simple venting), or if the vessel has controlled head pressure (non vented) has much to do with the "shelf life" of these fuels. I would suppose that if the proper storage method were employed, light fuel oils could remain viable for decades on end. But then questions like, "Why store this stuff when we can just make some more?" might arise. As an active member of USMC (Thank you Sir!) you might be able to put out some "feelers" about long term storage of fuels as addressed by our U.S. military. I have heard that our military has (or did have) ships loaded with all types of gear, equipment and vehicles docked at Diego Garcia in "very long term storage" conditions. I don't know if fuel for the vehicles is/was stored as well. You might be able to find out something about "fuel storage" if you can throw some questions in that direction. Just a rambling series of thoughts.

Mownie,
That would be the Maritime Prepositioning Force, three squadrons of cargo vessels capable of embarking enough supplies and equipment to fight a war on 24 hours notice.
No idea how they stabilize their POLs.

Here is a link that might be useful: MPF

Thanks for the link. Interesting articles.

Sea Foam - you're supposed to be able to clean all the carbon out of your engine by pouring a few ounces into your carb while the engine is running. Once it stalls, let it set 10 minutes, then start it up and watch the white smoke pour out, followed by the experience of a smooth running, carbon free engine.

In reality, you may find that those carbon deposits were the only thing maintaining a tight ring or valve seal, so beware.

I guess as an additive it helps keep things clean.

Stale-bil?

Un-sta-bil?

De-sta-bil?