As winter approaches, it reminds us that it is time to winterize not only your home and car, but also your gasoline-powered equipment such as lawn mowers and garden tillers, as shown in Figure 1. Winterizing will help extend the life of your small gasoline engines and extend the working life of cordless battery tools.
Figure 1 - Assortment of powered garden tools
Why Is It Important to Winterize
Winterizing is important because gasoline left in an engine's fuel tank and carburetor can degrade over time. During storage, gasoline can interact with air and moisture to form gums and deposits. Therefore you should not store gasoline in the engine's fuel tank for any inactive periods longer than one to two months.
To winterize your small gasoline engines there are two different approaches you can take.
Drain the Tank and check the owner's manual for information on draining the fuel system for off-season storage. If recommended for your specific model, draining the tank will reduce evaporative emissions that occur during storage.
If the owner's manual says the gasoline can be removed and it can be done easily, the gasoline should be carefully drained from the tank and carburetor, if possible and collected in a clean, approved storage container. Any remaining gasoline in the system can be removed by operating the engine until it stops. If you want to make the extra effort, adding a small amount of oil through the spark plug port also helps winterize an engine.
Use a Fuel Stabilizer if the gasoline cannot be easily removed. A gasoline stabilizer should be added to the fuel in the tank to minimize air space in the engine's fuel tank and fill the tank full with the gasoline/stabilizer mixture. The engine should be operated for a few minutes to draw the stabilized gasoline into the carburetor. For added protection you may want to consider taking the time to close the engine's valves. For engines with hand-pull starters this can be done by pulling the cord until resistance is felt.
Storing Battery Powered Equipment
After you have used your battery lawn mower for the last time this season it's a good idea to remove your lawn mower battery for the winter and store it in a cool, dry place. Be sure to store it away from gas cans, the water heater or furnace.
Disconnect the battery cable from the battery; starting with the negative cable (it will have a minus sign). Remove the battery and wipe it off with a cloth. Clean the battery terminal using a metal brush, or clean it with a battery cleaner product. Store your mower in a dry, protected place such as your garage or a garden shed. Never store it next to a furnace, water.
You should also store your motorized lawn and garden equipment in a cool, dry place that is well ventilated and out of direct sunlight.