idosubaru Posted July 18, 2008 Share Posted July 18, 2008 I've heard all the talk about old gas but I'd like to hear what actually happens when a car has problems with it. then there's the "this car sat for three years, i gave it a new battery and it started right up" threads. Online i didn't find much - yes it can go bad but it depends on lots of things..exposure to air, transport, refining, blah, blah blah. So - what really happens and does it ever actually happen? Does it start at all? Does it run bad? This is semi-related to a non-starting car I have now, but I've always wondered about this anyway and figured it would be good to learn/decipher the truth here in a separate thread. Link to comment Share on other sites More sharing options...
DaveT Posted July 18, 2008 Share Posted July 18, 2008 I would like to know what happens also. I figure the lighter components evaporate away. Car gas tanks are not sealed, temperature changes will eventually vent fumes & bring in air & moisture. Gas over 2 years old mixed with fresh runs ok with a ratio of 2:6 - 2G of old 6G of new. The old stuff is filtered & settled to remove water. I've run some fresher dead gas straight, with no trouble. Some I had to mix 50/50. I would think that with the lighter, more volatile components gone, it would be harder to burn. But when the old gas / new gas ratio is too much too old, I get knocking. So add a couple more gallons of new, problem fixed. Another sign of close to too much too old is harder starting. But this I would expect, since less volatiles would be even further reduced by the cold temperature. Link to comment Share on other sites More sharing options...
nipper Posted July 18, 2008 Share Posted July 18, 2008 http://autos.aol.com/article/general/v2/_a/does-gas-go-bad/20070703144909990001 that sums it up. nipper Link to comment Share on other sites More sharing options...
screwbaru2 Posted July 18, 2008 Share Posted July 18, 2008 I know the one year I did not use stabilizer in my lawnmower I had to flush the gas out and refill it before it would start. I kept gas for over a year in a 55 gal drum buried in the ground (don't ask) with stabilizer in it with no problems. Good article Nipper. Link to comment Share on other sites More sharing options...
nipper Posted July 18, 2008 Share Posted July 18, 2008 I know the one year I did not use stabilizer in my lawnmower I had to flush the gas out and refill it before it would start. I kept gas for over a year in a 55 gal drum buried in the ground (don't ask) with stabilizer in it with no problems. Good article Nipper. i made the same mistake with my first motorcycle. Had to rebuild 4 carbs, sidedrafts no less, yuck. nipper Link to comment Share on other sites More sharing options...
idosubaru Posted July 18, 2008 Author Share Posted July 18, 2008 http://autos.aol.com/article/general/v2/_a/does-gas-go-bad/20070703144909990001 that sums it up. nipper ha! that's the article i read as well when i searched - but it was on MSN or something else...must be an AP thing or something like that. i found the commentary under the article more enlightening "i used 2 year old gas and it was fine". i'm still wondering if anyone *really* has actually experienced it. i'm not surprised it can go bad, that it degrades, or of the chemical complexity of it, of course it wouldn't last forever. and if it does cause problems, no start, poor running, bad mileage....what do people actually experience? Link to comment Share on other sites More sharing options...
nipper Posted July 18, 2008 Share Posted July 18, 2008 ha! that's the article i read as well when i searched - but it was on MSN or something else...must be an AP thing or something like that. i found the commentary under the article more enlightening "i used 2 year old gas and it was fine". i'm still wondering if anyone *really* has actually experienced it. i'm not surprised it can go bad, that it degrades, or of the chemical complexity of it, of course it wouldn't last forever. and if it does cause problems, no start, poor running, bad mileage....what do people actually experience? Didnt i just say i expierienced it? It gums up the tiny itsy bitsy fuel ports in the carb or fuel injectors so fuel wont atomize. It depends upon how big the ports are. ALso if you put in fresh fuel, fuel is solvent. It will dissolve the gum. http://www.cnn.com/2008/LIVING/wayoflife/04/09/aa.bad.gas/index.html Some others...since you dont believe us :-p http://en.allexperts.com/q/Motorcycle-Repair-837/98-Yamaha-FZR-600.htm http://au.answers.yahoo.com/question/index?qid=20080525044929AAXl1H9 it's a common problem with seasonal engines. The more low tech the engine, the less it is affected, but eventually even the lowest tech will have an issue. nipper PS Your not getting any coal this year Link to comment Share on other sites More sharing options...
idosubaru Posted July 18, 2008 Author Share Posted July 18, 2008 Didnt i just say i expierienced it?............................Some others...since you dont believe ushey! you assume the worst of me (usually that might work) - you were posting when i was - i didn't see it until after i posted. i will say that my fully developed hate of carbs is probably due, a little bit, to the gas and what it does to them. but they still suck from here to mars! Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 18, 2008 Share Posted July 18, 2008 It draws moisture for one thing. The VW I recently resurrected sat for 12 years in a damp garage. It had about 1/8 to 1/4 tank of very old, very varnished gas in it. Probably started out as more like 1/2 a tank. The lighter components do evaporate, and the gas draws moisture from the air. That moisture condenses in low temps and rusts out metal tanks, etc. It will collect at the lowest point in the system. I had to open up the fuel pump and clean the rotor as it had a thin film of rust keeping it from turning. It the case of the VW it wasn't terminal. Once I got the pump turning again it fired right up (fuel injected even!) and I filled the tank with fresh gas and immediately drove it through a full tank (once I got the brakes fixed). GD Link to comment Share on other sites More sharing options...
The Dude Abides Posted July 18, 2008 Share Posted July 18, 2008 Not exactly 12 years but i would leave my 73 monte carlo in the back yard during the cold months to keep it out of the way. It had a half tank of gas every time. Every spring the thing would fire up with no problem. Ok say ive got a couple of lawn mowers that might be like this. Is there a way i could just clean up the carbs or do i need to have them rebuilt. Ben Link to comment Share on other sites More sharing options...
DaveT Posted July 18, 2008 Share Posted July 18, 2008 i'm still wondering if anyone *really* has actually experienced it. Look at my post above? (I don't mean this to sound snippy) The ratios are what I found made it workable & how to adjust the them. From experience. I'd like to know more details about the chemical changes. Link to comment Share on other sites More sharing options...
94Loyale Posted July 18, 2008 Share Posted July 18, 2008 Well, as far as old gas goes....I've got plenty of experience with that. As my job, I am a BMW and Triumph motorcycle tech. During the winter months up here is when I get all the project bikes to work on. The older ones that have been sitting forever. After cleaning many fuel tanks and cleaning carbs up. Old gas reaks havoc on all of it. It turns into a varnish kind of stuff. Real sticky. But especially with carbs. It clogs up all your ports and jets and makes things real hard to run, if you can get them to run at all. That's why if your going to let something sit, you should drain the bowls on the carbs. But I'm getting off subject, and its late. When taking fuel tanks off to clean, I've had petcocks blocked solid and uncleanable. This could be after just a few years, or 20 years. It all depends on how much gas was left in the bike, and the environment it was stored in. I know I'm speaking about bikes here, but the technology goes hand in hand. As far as cars go...I've got cars to run that have been sitting for years, and they ran decent. As I said before it all depends on the conditions. And I've had ones that wouldn't run at all. The gas goes bad, and everything gets messy and stuck. I've never had as much of an issue with fuel injected stuff that sits as carbs, but that is for obvious reasons. As the carb has much smaller parts, and plenty of places for the fuel to sit. Also, as the gas gets old, it does not fire as easily, and will generally make the vehicle run like ************. But like someone else already said, gas is a solvent. If you add some new gas to the system it will definately help to clean things up. Pardon my rant, its been a long day, 9 to 10! and I just got back from the bar Link to comment Share on other sites More sharing options...
Nug Posted July 18, 2008 Share Posted July 18, 2008 I have an XR400R Honda dirtbike. If I leave it in my hot garage for a month and try to start it, it will do nothing except wear your leg out trying to kick it. I shut the petcock off and drain the carb bowl.Then i turn the petcock back on and let it purge for a second. The fuel that has been sitting in the carb looks and smells different, less volatile than what has been sitting in the plastic tank. The bike will start in one kick after that. Link to comment Share on other sites More sharing options...
bheinen74 Posted July 18, 2008 Share Posted July 18, 2008 I am going to get out my civic from storage, last time i put any gas in it was probably in 2006. it ran fine last summer for the 25 minutes i run, but the gas was 1 yr old then. This time, it will be 2+yr old gas. will report after this weekend. Link to comment Share on other sites More sharing options...
Ginger48 Posted July 19, 2008 Share Posted July 19, 2008 I'm sure how fast gasoline deteriorates depends on the climate. My 87 Subaru sat unused for 3 years in the garage with 1/2 tank of fuel in a cool very dry climate. It started right up 2 months ago as if it had fresh gas in it. My old 1945 Jeep has sat with the same gas in it for up to 8 years at a time and never experienced any problems. I believe heat and moisture are the killers. Link to comment Share on other sites More sharing options...
94Loyale Posted July 19, 2008 Share Posted July 19, 2008 Heat, Moisture, tank venting, and the amount of fuel in the tank. All contribute for sure. Link to comment Share on other sites More sharing options...
kiwi subbie Posted July 19, 2008 Share Posted July 19, 2008 with all the old gas i get out any car i wreaked even if it was 5yrs old or so we just filter it an run it in dads old classic van. it was only 2 cylinder and low compession. it didnt mind it at all lol. Link to comment Share on other sites More sharing options...
WoodsWagon Posted July 20, 2008 Share Posted July 20, 2008 The main thing to do with small engines and carborators is to run them out of gas, and store them empty. Shutting off the petcock on your bike and letting it run untill it stalled would be a better way of storing it than draining the bowl every time you need it to start. I've revived a lot of "junk" snowmobiles by taking the carbs apart and doing a thourough soak and cleaning. Metal tanks you want to leave full of gas, with a stabilizer in it. What the stabilizer does is create an oil film on top of the gas, preventing the VOC's from evaporating. It also helps keep water out. Most of our gas these days is 10% ethanol, wich helps keep the water in suspension in the gas. Leaving a tank half full or empty leaves a bigger area for condensation to form inside the tank. The condensation pools on the bottom of the tank, water being heavier than gas, and rusts the bottom of the tank out. Link to comment Share on other sites More sharing options...
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