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Why Does My Craftsman Mower Stop Running?

Whether it's old or brand new, at some point, a Craftsman mower may stop running. This can happen for a wide variety of reasons, and finding a broken part can seem dizzyingly complex. However, focusing on the main engine areas -- fuel, air, spark and compression -- will help narrow down the reasons the mower stopped running.
  1. Fuel Problems

    • Fuel problems occur regularly in many gas engines, including a Craftsman lawnmower. Bad, or old fuel will leave behind a sticky deposit, gumming up the fuel tank, fuel filter, fuel hoses and inside the sensitive carburetor. Most running problems occur due to fuel supply restrictions, so it's sensible to start here. Dump any gas older than two weeks and check and clean the fuel tank. Replace the fuel filter and the fuel hoses. Leave more difficult carburetor adjustments, cleaning and servicing to a professional.

    Air Problems

    • Air problems will stop a Craftsman mower from running well, eventually shutting it off when the engine chokes. The Craftsman mower uses air for the fuel and to keep the engine cool. Overheating and air-flow restrictions can cause engine damage. Take out the air filter's foam pad and replace it. Wipe off anything around the air filter and inside the air filter box. Open the muffler cover and remove the spark arrestor screen to clean it with a wire brush.

    Spark Problems

    • Without a high-voltage spark, no amount of fuel and air will ignite. This spark also needs proper timing to discharge just as the fuel reaches the combustion chamber. Spark plugs will get fouled with carbon, become bent or rounded off and no longer fire properly. Replace the spark plug yearly, preferably at the beginning of the season, and check it periodically throughout the season. Leave all other ignition system repairs to a professional as it contains lethal amounts of voltage.

    Compression Problems

    • For everything to work in sync on the Craftsman lawnmower, enough compression is required to push everything through and keep it all moving. Without compression, the fuel won't reach the gas tank and the engine will die. Compression problems occur when a leak inside the engine causes an excess of air or an excess of compression. Also leave compression problems to a professional for repair.