Home Garden

My Husqvarna 48-Inch Mower Will Not Stay Running

A Husqvarna 48-inch lawnmower will not stay running if it loses spark, airflow, fuel or compression. These vital systems not only must be present, but need to be present at the right combinations at the right time. Find the missing element in the engine and you can determine why your Husqvarna lawnmower won't stay running.
  1. Fuel

    • Most running problems on a Husqvarna lawnmower occur when the fuel system gets blocked or hindered. Impurities in the fuel, old gas or bad gas will all slowly clog up the fuel system. Once the fuel is restricted too much, the engine will shut off. Common problems in the fuel system include a dirty fuel tank, dirty fuel cap, dirty fuel filter, clogged fuel line and a dirty carburetor. Never leave any fuel in the tank or system if you're storing the mower. Replace the fuel filter and fuel hose every season and clean the fuel system thoroughly.


    • When the fuel reaches the cylinder, the spark plug ignites it. The spark originates from the ignition module, housed next to the flywheel. As the flywheel revolves around the crankshaft, it builds magnetic energy, which trips the module, firing off the spark to the plug. A poorly functioning module, spark plug or plug wires will often cause a mower to stop running. Replace the spark plug at least once a season. Check all ignition wires to see if they're broken, cracked or frayed. Always remove the spark plug and ground the ignition wire before inspecting the ignition system.


    • Clean, cool air needs to move into the system unrestricted, and the heated gases need to leave the system unhindered. Dirty air filters and mufflers often cause a loss in the airflow into and out of the engine. Pull the air filter out and clean it after every eight hours of operation. Wash the pad in soapy water and allow it to dry completely. Clean the muffler, spark arrestor screen and exhaust port after every 90 hours of operation. Use a wire brush to scrub off any built up carbon deposits.

    Loss of Compression

    • For the moving parts to continue moving, the engine needs vacuum pressure, often referred to as compression. If air is leaking into the system, the machine will often start up but die as it's accelerating. Air leaks often occur around old gaskets and seals around the crankcase and cylinder. Loss of compression will also translate into a loss of power to the moving parts, such as the crankshaft or piston. Compression problems can be difficult to diagnose and expensive to repair. Take the mower to a certified mechanic if you suspect compression problems.