As winter approaches, you are likely doing less with your chainsaw. Before putting it away for the winter [or any time more than a couple of weeks] be sure to take these steps to ensure it is ready to start up again when spring comes…
The first issue you need to consider is the fuel. Most of our fuel now contains ethanol- a plant derived fuel additive. If you let your chainsaw [or any other motor] lay around for more than three weeks, the ethanol will quickly begin to breakdown and clog up the ports, jets, and fuel line if left untreated. Do not run it out of gas for the winter, as this will allow the interior seals to dry and possibly crack. Instead, empty the gas out [in a well ventilated area] and pour in a little ethanol-free gas/oil mix, run the saw for a few seconds to completely coat the interior, and then shut it off and store it. Doing this will keep the seals moist and the carburetor won’t gun up. When you are ready to use your saw again, add back your standard gas/oil mixture.
NOTE: if you don’t use your chainsaw often, only using an ethanol-free gas/oil mix may be the way to go. A 72 oz. can fill your tank 2-3 times and can last in the tank for 2 years without worry.
Now is also a good time to remove the air filter and thoroughly clean it [follow your manufacturer’s instructions]– usually washing it with soap and water [for paper-type air filters] or fuel [for a wire-type filter]. They also are pretty cheap- so you can always just replace it.
Next we address the ignition system… At a minimum, you should remove and inspect the spark plug–look at the condition and color of the electrode on the bottom of the spark plug. A slight grey is what you want to see. A black, sooty, or oily electrode is not. If you have any doubt, just replace it with a new one.
While you have the spark plug out, spray a light household oil into the cylinder port to help keep it lubricated over the winter. Mildly dirty spark plugs can be cleaned with fine sand paper, but make sure to clean off any sand particles that remain on the electrode prior to reinstalling.
Another thing to check is the pull cord for tears/fraying.
While not necessary, it is nice to sharpen your blades to make sure it is 100% ready to go the next time you go to use it. See here for tips on sharpening your blades.