"Pure gas". How long does it stay good?

[KEITH KRAUSE]

After taking my carbs apart for cleaning twice in the last 2 years I've decided to run only pure gas. I'm lucky there's a station close by that sells 91 octane pure gas.
I still won't be riding the GS more than 100 miles a month (?) and it will still be in a very hot (100 degrees) garage during the summer.
For convenience, I'd like to fill the tank (5 gallons) but that would mean the gas needs to stay good for 5 months. I think that's pushing it. To be safe and avoid gumming up the carbs again, how long would you keep pure gas in the tank?
I know a lot of you run only pure gas and have experience with it. I've run ethanol gas for so long I cannot remember using pure gas. I never had problems with ethanol gas in the past but I know it's storage life is much shorter and I'm sure my hot garage is making things worse.
I want to have a safety margin, so would you recommend getting fresh gas every 2 months...3 months? Thanks for any help.

[Tom R]

I've had good luck with stabil over the winter.

[chuck hahn]

If its gonna set 5 months as expected then do the long term storage as lined out in the service manuals. Its basically what i preach except i add in drying the carbs with compressor air down the fuel line once the bowls are drained. Pure gas will be ok for 5 months... Ive done it and I wouldnt tell you otherwise. Someones gonna chime in about this but take whoevers experience you choose I guess.

1.. Remove the fuel line from tank and drain the bowls into a tuna can or something you can slide under the bowls.
2..Dry the bowls well with compressed air and then close all drains.
3..Stick a bolt into the fuel line to keep out bugs.
4..Place a rubber cap over the fuel line nipple on nthe petcock. Available at any auto parts store.
5..Fill tank to just below the filler hole. Leave a little expansion room and put the gas cap on.

I promise you when you get the bike back out and hook up the fuel line it will start as it should and youll ride away like it was yesterday. Run the gas out and fill with new gas like normal.

[wymple]

I just drained the pure gas with Stabil out of 3 bikes I have stored, and put in fresh gas. All 3 were done in February of this year, and all three drained out looking thick and smelling bad. Stabil will not get any votes from me, I could have gotten better results without it.

[Steve]

We don't have pure gas available here, but if it were my bike, I would probably add StaBil as a preventive measure, anyway.

Yeah, the ethanol evaporates out of the float bowls quicker than pure gas, but even pure gas evaporates, so either treat the gas or drain it.

.

[jabcb]

There are some competitors to Stabil. Are any of them better?

[Alan Schlosser]

I've run "pure" gas for years in the bike and lawn equipment. I do put a splash of Sta-Bil in before the end of the season. Never drained the carbs and never had an issue starting things up in the spring.

[Nessism]

I think the problem relates to fuel inside the float bowl's evaporating and turning to varnish. Whether or not you use pure gas or regular gas/ethanol fuel the remnants of the evaporation process may cause issues. Personally, I've had great results using Marine grade Stabil along with standard ethanol laced fuel. My bike sometimes sits for 2-3 months between starts and I haven't had any issues with gumming since I started to use Stabil. I think the ideal process would involve treating the gas with Stabil, running the bike long enough to get it all through the carbs, shutting down and then draining the float bowls. The small amount of remnant fuel in the carb passages shouldn't hurt anything.

[Dogma]

One bowl of gas evaporating over winter or longer has never done me any harm. Stabil or similar is a must, to keep the water from separating out of the fuel. When the bowls fill with water on the first prime in Spring, it's just no good (and may lead to rust). I used to forget to stabilize my gas mower almost every fall, and in the spring I had to drain some fuel out of it before it would start.

A few years ago, a strange thing happened. The airbox boots on both GSs shrank and hardened over winter. There was some sticky residue on the bottoms. No idea what caused that. This was back when the Brown County rally was in May, so I discovered this on the day of departure. I ended up swapping the 1000G boots onto the 850 and rode that, with gas that was about 3 years old. Power was way down on that first tank, and it got about 28 mpg. The next tank of fresh fuel brought it back to itself.

I should probably run a tank with SeaFoam through them every season as insurance, but I haven't had any varnish troubles with either since rebuilding the carbs years ago.

BTW, I hear they're looking to legalize E15.

[Steve]

I think the ideal process would involve treating the gas with Stabil, running the bike long enough to get it all through the carbs, shutting down and then draining the float bowls. The small amount of remnant fuel in the carb passages shouldn't hurt anything.

My standard procedure (when I remember to do it ops) is pretty similar. I think the suggestion is to add one ounce of StaBil per gallon of fuel. I double that. I like to start with a partial tank (half or so), add 8-12 ounces of StaBil then ride the half mile to the gas station. That loads a super-concentrated mix through the carbs. I fill the tank, which reduces it to a double dose, then go for a ride "around the block". Depending on the weather, the "block" might be 2, 5, 10 or 25 miles. With any of them, treated fuel is in all circuits in the carbs. I don't bother draining the bowls.

.

[Nessism]

My standard procedure (when I remember to do it ops) is pretty similar. I think the suggestion is to add one ounce of StaBil per gallon of fuel. I double that. I like to start with a partial tank (half or so), add 8-12 ounces of StaBil then ride the half mile to the gas station. That loads a super-concentrated mix through the carbs. I fill the tank, which reduces it to a double dose, then go for a ride "around the block". Depending on the weather, the "block" might be 2, 5, 10 or 25 miles. With any of them, treated fuel is in all circuits in the carbs. I don't bother draining the bowls.

.

Steve, you should look into the Marine version Stabil. You only need 1 oz for 5 gallons. Anyway, I agree with your approach to get stabilized fuel into the carbs. I don't normally drain the carbs either but Keith lives in a hot environment so maybe getting all the fuel out would be a good idea?

[KEITH KRAUSE]

I appreciate the replies.
I used Stabil anywhere from the normal dosage to twice the dosage and the carbs still gummed up. I haven't tried the Marine grade Stabil. I don't doubt Ed's advice but I wonder if the hot garage is too much for a fuel stabilizer to work as you want it to.
If I make sure to put in fresh pure gas no longer than every 6 weeks, do you think the carbs will be OK?

[KEITH KRAUSE]

By the way, I just got the carbs back together, cleaned, new o-rings throughout.
The damn fuel T failed the leak test. Oh well, it was the original T. Didn't leak 20 years ago when I took everything apart but just bumping it a few times while cleaning things this time disturbed it too much. Thank goodness for Z1 Enterprises. $18.95 for the T and $24 for the 2 connector tubes with all O-rings provided. Since the new aluminum T has o-rings instead of being all rubberized, I can just order new o-rings if I ever need them. I have left over o-rings from Robert Barr's VM o-ring kit. I wonder if his o-rings can be used on the Z1 T?
The new T is made of aluminum. Any opinions on it's longevity? I thought they were made of brass. I was told a million years ago the carb bodies are made of "pot metal"?? The T fitting appears to be the same metal.

[chuck hahn]

Yes they can....and i have found Z1 orings are often way to big and very difficult to get the fuel tees into carbs. Roberts are far superior in my opinion.

[Nessism]

Is the fuel tee anodized? If so it should last. If not...it will corrode more easily.