1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

what to do about old gas?

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Old 06-24-11, 03:57 PM
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the name is Stan

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what to do about old gas?

my '85GS has been in moth ***** for over a year now.
I start her up every now and then. Even if it's been over a month
she starts up within 10 secs. She needed to have the carb rebuilt
even before I took her off the road. Although my gas gauge isn't reading
anything, I know I parked her with nearly a full tank.
The gauge goes from Full to Empty once I go below 3/4 tank. so the question is...

before the gas really goes bad, should I just drain her now, or
throw in some fuel stabilizer now?

It may be a year or more until I'm ready to put her back on the road.

I guess the old gas could be used in my Honda mower.
Old 06-24-11, 04:29 PM
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i'd drain the gas and use it elsewhere. put in fresh gas and mix in stabilizer with the fresh gas.

the fuel level senders are a common failure. i would purchase a new sender from the dealer and drop the tank and install. i have a gas tank removal writeup with pictures. if you are interested i can post it.
Old 06-24-11, 04:35 PM
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Get rid of the old gas, the newer blends don't last as long as they used to. You don't want to pump all kinds of crap into a fresh carb, clean the tank too.

My favorite joke about using old gas: " How much milk do you need to add to bad milk before you can drink it"? Keep that in mind.
Old 06-24-11, 07:59 PM
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Stabilizer (like Seafoam or Stabil) is a must, but as said, start with fresh gas. Your RX has a drain so no prob getting the old stuff out for your lawn mower

Tank needs to a be as FULL as possible to eliminate _air pockets_. Otherwise condensation will create rust issue in the pocket = plugged fuel lines=tank-pull to clean & re-line.
Oh, and change the fuel filter before you put in back on the road.

BTW oil/seafoam combo squirted/poured into engine via carb mouths and HAND (or "dry") cranked (ie no spark attached) is a great idea to keep things spinning there too.

Unless you can run the car long enough to completely heat to normal range, the condensation (hot exhaust/cool air) issues internally do more harm than good. If properly lubed up and sealed, engine will be fine for years with nothing more than ocassional hand/dry crank over.

I seal the carb mouth AND the exhaust pipes to keep moisture out of the engine and exhaust internals.

Stu Aull
80GS
Alaska
Old 06-24-11, 09:28 PM
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Originally Posted by jgrewe
" How much milk do you need to add to bad milk before you can drink it"? Keep that in mind.
Lactose intolerant me found that to be real funny!

I do run it for a minimum of 30 mins each time I start her up. I'll take this as an opportunity to get me a new sender before they become unavailable. This is something i'd like to do before rebuilding the carb.

Thanks a bunch!
Old 06-25-11, 12:57 AM
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If I still had my scout II I'd tell you to dump it in that, it would run anything that would ignite just the same :x

personally I'd drain it and put new gas in. might even wash some sediment out too.
Old 06-25-11, 02:40 AM
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i would dump that gas. i have read that if your storing a rotary for an extended period it is a good thing to squirt a little tranny fluid in through the plug ports. i guess that supposed to help maintain your apex seals. dont take my word for it though, you know how the internet is..... just cause you read it doesnt make it true.
Old 06-25-11, 06:53 AM
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As long as the tank is full, don't worry about it. As long as the tank is sealed up, it's not an issue. (One more reason why OMG REMOVE TEH RATS NEST is bad: the evap system is there for a good reason)

Tank varnish happens if the car sits for ten-twenty years and the fuel is allowed to evaporate away. Gasoline isn't a chemical, it's a cocktail of dozens/hundreds of chemicals, and the lighter ones evaporate first. An airtight tank won't allow the light fractions to leave the system, and a full tank will prevent condensation rust on the inside.

You're only talking about a year or two. That's not that big a deal.

I would, however, recommend using fogging oil in the engine and DON'T start it all the time. That doesn't do anything useful and it does introduce the possibility of problems since you aren't really warming the engine fully (see: carbon lock) but you are still doing a lot of cold starts (diluting the oil with fuel and moisture) as well as adding heat cycles to the fuel.

In about 2003 or so, I drained seven year old fuel out of a junk car and put it in my RX-7, worked just fine.
Old 06-25-11, 09:17 AM
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my FC passed the california emissions test on 12 year old gas...
Old 06-26-11, 12:32 AM
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Just my experience...
I have not had much luck with gas older than 3 years. My mower would not start the 4th time I put 3 year old gas from my truck in it.
I don't "think" any automotive gas tanks are sealed, they have to vent to relieve pressure. Ever go in the hot garage to fuel something up and the plastic gas can with no vent is blown up like a balloon? I have. Maybe they can be completely sealed, and thus prolonging the usability of the gas? I'm 'thinking" it's not economically viable to make the tank thick enough, or the fuel system able to deal with the pressures variable with the temperatures. Older cars did have vented caps before emissions were a concern.

Removing the rats nest doesn't include the removing tank vent, charcoal canister, and pcv/purge valve.

Sorry, but I have nearly 10 gallons of gas in my garage, most of it is not more than 5 years old, and won't even burn in my mower. It's difficult to get rid of. If you have any in question, I would say use it in what ever you can, while you can. Especially if you're on a tight budget.
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