Spark Plug and Ignition: A two-cycle engine, with its gasoline-and-oil fuel mixture, is more likely to foul spark plugs than is a four-stroker. Use a plug or socket wrench to remove the spark plug, then wire-brush it clean and reset the gap—with a feeler or a wire gauge—to the recommended limit (usually .020" or .025"). The electrodes at the tip of the plug should be an even dark gray-to-brown color. If they're not, it indicates one of any number of problems—from a poor fuel mix to an air leak—that you should refer to your service shop. When you replace the plug in the cylinder, tighten it moderately but not excessively. And if you purchase a new plug, be sure you get the correct type for your saw. Some newer chain saws utilize electronic ignition, which is maintenance-free. If your older model has breaker points, you'd probably be better off letting your repair shop do the adjustments.
MOTHER EARTH NEWS STAFF