Fuel Handling and Storage

What You Need To Know About Running Ethanol Gasoline In Small Engines

Running Small Engines

Typical 2-cycle engine machines: Chainsaw, string trimmer, hedge trimmer
Typical 4-cycle engine machines: Generator, lawn mower, lawn tractor, wood splitter

1. Today’s gasoline is almost always mixed with ethanol. Ethanol can harm some of the internal parts of small engines. If you have access to aviation gasoline to use in your small engines, all of the following procedures that deal with gasoline and ethanol can be avoided because aviation gasoline contains no ethanol. Aviation gasoline can be stored for about 6 months.

2. If you don’t have access to aviation gasoline, always use high-test gasoline in any small engine.

3. Gasoline containing ethanol for use in small engines cannot be stored in a gas can or inside your small engine for extended periods of time. The gasoline/ethanol mixture becomes unbounded after about one month and then the ethanol will begin to harm your small engine.

4. Adding a fuel stabilizer to the gasoline you use for your small engines will help to minimize the effects of ethanol because it helps to keep the gasoline and ethanol bonded together. The best fuel stabilizer to use is a marine-grade stabilizer which is frequently colored blue (Star-Tron is one brand). Follow the stabilizer manufacturer’s directions for mixing the stabilizer with your gasoline. The usable life of stabilized gasoline is about two months.

5. Gasoline older than two months, even after it has been stabilized, should be used up in your car, and then go get fresh gasoline. It is perfectly acceptable to use up any old gasoline in your car, even if it has been stabilized or had 2-cycle engine oil mixed into it. Do this when you have a nearly full tank of gas and it will be safely diluted.

6. Small engines need to be run at least once a month for several minutes to help keep the gasoline/ethanol mixture mixed up and bonded together. In between uses of your small engine, especially for generators, keep the gas tank about half full, so that twice a year, you can pour in about a half gallon of freshly-purchased, freshly-stabilized gasoline.

Storing Small Engines

1. MotoMix 2-cycle engine fuel contains no ethanol and is formulated to allow 2-cycle engine storage for up to two years. To store a 2-cycle engine, start up and run the engine dry of the of the existing gasoline in the gas tank. Then put in 2 to 3 ounces of MotoMix fuel and run the engine for about one minute. Then shut it off and put it in storage.

2. To store a 4-cycle engine, do not run the engine dry. If you have been using unstabilized gasoline, pour some stabilizer directly into the gas tank. The amount of stabilizer you pour in should be the correct proportion to the amount of gasoline in the tank according to the stabilizer manufacturer’s directions. Don’t worry about stirring the tank; the vibration of the running engine will mix the stabilizer and gasoline. Run the engine for one minute, then shut it off and put it in storage. Don’t worry about repeatedly adding stabilizer because you cannot over stabilize gasoline.

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