How long does it take for fuel to go stale?

[Theweapon52]

My question is exactly that. My bike has been in storage for just over 2 months now and i did not add any stabilizing additives to the tank, am i in trouble?

My bike is also fuel injected and i only use 91 octane, does that make any difference?

Cheers!

[BuzZz]

Gasoline starts to 'go bad' the minute after it is refined. It starts flashing off the lighter (most flammable) constituents as soon as it is exposed to the air. If you can smell gasoline, you are smelling it lose it's potency.

The trouble with gunk, goop, and varnish starts sometime later and is just residue from those lighter ends flashing off building up in the remainder. This takes time and that varies on the exact recipe of the fuel and how it was stored. Metal containers keep are more impermeable to the smaller molecules of the lighter vapors than plastic, for instance

All that don't answer your question, does it?
You're probably OK with your bike at 2 months. You might want to run some injector cleaner through it after you burn off this left over tank... even in this tank. But that is more to ease your own mind than anything else......

[HYPERR]

Actually funny you ask that because we just had a warm day and I started up and rode three of my bikes that has been sitting since early December(so just about 2 month). I have been riding my KLX250S during the winter months because of the snow, slush, and all the sand/salt on the road. The three bikes that I did not ride were connected to a battery tender but I did fail to stabilize the fuel or add any additives as I never anticipated that all three would sit so long.

Here are the results. All 3 bikes are fuel injected and are in tip top running condition. The BMW had 93 octane in it, the Ducati 89, and the Honda 87.

BMW R1150R: Took three attempts to start and run. It always started on every crank but it backfired, hiccuped and stalled twice. Once running though, it ran flawlessley.

Ducati Hypermotard: It has the servo starter so it starts on its own. It went through the first crank session and it made no attempt to start at all. On the second crank session, it started and stalled. It started instantly on the third crank session and it ran flawlessly.

Honda CBR600RR: I hit the starter and the bike started instantaneously like it always does. Afterall it is a Honda.

I took all three bikes for a ride between 10 - 15 miles and they all ran perfectly. So from my experience, the gas was fine after 2 month. Of course it also depends on the blend of your area and how much junk they put into your gas.

[TEvo]

I have heard that any quality modern gasoline is stable and robust enough to last through a typical CONUS winter without the need for additional additives or fuel stabilizer.

Off topic: I wish Ducati would get rid of that servo assisted start feature. From my experience, it doesn't add anything except a feature that tends to drain the battery.

[BuzZz]

I've heard the same thing about modern fuel. I only half believe it. Marketing will lie to the public with no qualms whatsoever, so always have a grain of salt handy when reading anything from some big company's marking department... specially an oil company.....

And fuel stabilizer is cheap peace of mind for me, but I wouldn't lose a ton of sleep over my gas if it was only a few months of storage.

[TEvo]

On the flip-side, it also makes you wonder how much "marketing" the fuel stabilizer manufacturers do...

At any rate, I'll find out this year. I forgot to go get stabilizer when I stored the bikes in mid-November. Looks like there will be a period of warm weather but realistically, I don't expect to be riding for another month.

[good old bikes]

Now all gas contains 10% ethanol and the ethanol actually sucks water out of the air. The ethanol is connects to water molecules like dry-gas. The new gas is supposed to last for about a month.

[Mr. Invisible]

The problem with gasoline is that after most of it evaporates it leaves behind a gooey substance resembling laquer.

I have a lawn tractor that I have never put stabilizer in and have had to clean the shutoff needle 3 times in 12 years. I have also seen the laquer left behind in one of my 5 gallon gas cans.

There are two ways to get rid of the laquer left behind. One is if the engine will run, run it and the gasoline will flush it through. The other, if it is built up too bad is to rebuild or replace the carb or injector.

My weedeater usually don't run good till the second or third tank of the year but that is also oil gum added to the laquer.