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Ethanol & 2-cycle


nyslowhand
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I have had lots and lots of problems with my Mercury 9.9 kicker trolling engine due to ethanol, even with the various additives (I have tried about all of them). I spoke to Mercury and they admit there is more of a problem on the smaller 4-stokes due to the smaller orifices in the carburetor. The smaller orifices are needed to satisfy new EPA rules on emissions. The smaller orifices result in finer atomization of the fuel and more complete combustion at the expense of greater liklihood of fouling. The best thing you can do on small outboards is to drain the bowl of the carburetor after each use or just disconnect the gas line and burn up whats left in the carb. You should do this even if you think your additive is effective. Advice from a marine engine mechanic with over 40 years of experience. If you leave gas with ethanol in the carburetor it will eventually leave behind the water and gunk caused by the ethanol. Even if you are using additives you will eventually get the problem if you don't get rid of the residual ethanol in the carb. I had a carb job done last winter only to have the carb get gunked up again before I even got to use use it and had to do another carburetor cleaning. By the way, Mercury recommends complete disassembly and cleaning all carburetor parts with an ultrasonic cleaner. For those interested harbor freight has one priced under $100.00. I now drain the bowl after each use. I am also in the process of switching to ethanol free gas, just filled up at the Nice and Easy in Brewerton. Its 91 octane but the engine owners manual says 87-92 is acceptable.

I plan to start using this ethanol free gas for my Stihl chain saw as well.

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That is sound advice adkbuck. What I have done on the garden tractor, the 4 wheelers and snowmobiles is put a shut off valve in the fuel line. I simply shut the valve off and let the remaining gas in the line and carbs burn up. Thankfully the big tractor is diesel. lol

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The Ethanol free fuel that VP Racing fuel sells there SEF smells just like there racing fuel.The premixed Stihl does not.I live up in the hills no large lakes with marinas that have ethanol free fuel.Next time I go down to NJ or Pa I will have to take a 5 gallon can with me and keep an eye out for one.

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Adk, you hit on a very good point about the emissions requirements and the size of the jets, etc. Nowdays they are much easier to plug up, so the gunk that comes off of the dry rotting rubber parts, caused by the ethanol, clogs them up really easy. Running all of the gas out of them is a good idea.

Wdswtr, good idea on the shut off valves. Still have to be aware of the damage the ethanol causes in the rubber fuel lines though. Maybe put the shut off valve upstream of a fuel filter just to be sure? I will have to pop one on my lawn tractor. Thanks for the idea!

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I found one marina in Saranac Lake that sells non-ethanol gas. $4.99/gallon. For my 1987 9.9 Evindrude I just unhook the gasoline hose and let the carb (bowl) run out of gas. This weekend I will need to check my Husquervarna chain saw to see if I can get it started as it has been sitting with fuel for over 3 months without running. It is a 3 year old model and I have heard that the newer engines are supposed to have non-metal parts that do not react with ethanol. Supposedly the older (pre-ethanol) engines have hoses, gaskets and other material that break down with ethanol. Hence the residue gets stuck in the small engine nozzles and holes in the carab(s)It has been siting with ethanol. I still may buy a couple of ethanol free gas and run it in my 9.9 and chain saw.

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Yes shutoff valve before the filter. This way it can filter out any debree/rubber breakdown before it hits the carb. You will eventually get to the point where you will know when to shut the valve off before parking the equipment. You will be suprised how long a small engine will run with just the gas in the line and carbs.

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Adk, you hit on a very good point about the emissions requirements and the size of the jets, etc. Nowdays they are much easier to plug up, so the gunk that comes off of the dry rotting rubber parts, caused by the ethanol, clogs them up really easy. Running all of the gas out of them is a good idea.

Wdswtr, good idea on the shut off valves. Still have to be aware of the damage the ethanol causes in the rubber fuel lines though. Maybe put the shut off valve upstream of a fuel filter just to be sure? I will have to pop one on my lawn tractor. Thanks for the idea!

Yes shutoff valve before the filter. This way it can filter out any debree/rubber breakdown before it hits the carb. You will eventually get to the point where you will know when to shut the valve off before parking the equipment. You will be suprised how long a small engine will run with just the gas in the line and carbs.

What I read and learned from others is that the older engines have hoses and gaskets that will dissolve partially with the use of ethanol enriched gasoline. Hence when the gas sits for a long time the rubber and gasket material clogs the small orifices. The newer engines have hoses and gaskets that resist the ethanol and do not leave any residue. I can see how this make sense. What I don't know is when did every engine manufacturer switch to ethanol resistant materials?? My 1987 Evinrude 9.9 HP is one of those that must have parts that leave residue. Two years in a row I had to remove the carb and clean it. Now, I just unhook the gasoline hose at the engine and let the engine run till it stops. This seems to work just fine.

My Husquervana chain saw seems and a small 4.5 HP lawn mower do not seem to have a problem with the ethanol gas. I started my chain saw this weekend after it sat for about 3 months with old methanol gas. But just to be sure I emptied the gas tank and let the saw run until it was out of gas. My lawnmower, (4 cycle) seems to be no problem.

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What you don't realize is the ethanol we burn in the states is not corn ethanol but sugar cane ethanol which is worse. We sell the corn to others and buy the sugar cane for our use but it's sugar so it gums the carbs and injectors even worse.

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