Keeping Your Lawn Mower Running

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  • 2-3 hours
  • Intermediate
  • 100-200
What You'll Need
Leaf blower (optional)
Small brush or broom
Siphon hose and gas can
Paint scraper
Garden hose
Bench grinder or new mower blades
Wrench or screwdriver
Oil drain pan
Spark plug
Socket wrench
Feeler gauge or gap tool
Air filter
Gas stabilizer

With proper maintenance, a lawn mower can last decades. Just as a car needs regular tune-ups, a lawn mower should be serviced once a season to ensure the best continued performance. Before beginning any work on your mower, unplug the sparkplug wire.

Step 1 - Clean

Debris buildup leads to an excessively warm engine and causes unnecessary wear and tear. It is important to clean away dirt and debris after every use. Utilize a leaf blower, small brush, or broom to remove any dirt or grass clippings from the engine block, cutting deck, or expeller shoot.

Clean the underside of the mower at least twice a year. Siphon any remaining gas from the mower’s tank before turning it on its side. Scrape off old clippings and dirt with a paint scraper or screwdriver. Wash the undercarriage thoroughly using a garden hose.

Step 2 - Check for Damage

Small animals frequently build nests inside lawn mowers. If the machine has been out of use for a time, check for these and remove them. Also check all wires and seals for damage.

Step 3 - Replace or Sharpen Blades

A sharp blade is essential to healthy grass. Replace or sharpen lawn mower blades at least once a season. If the area being maintained is large, repeat this step more frequently. When removing the blade, make sure to note the direction of the cutting edge for reinstallation.

Some shops offer blade sharpening services. However, this can be done at home using a bench grinder. If blades are older, they will often need to be replaced.

Step 4 - Change the Oil

Depending on the model of the lawn mower, drain the oil through either the oil plug or dipstick hole. If the mower will be tipped during oil drainage, first siphon out any remaining gas. Drain oil into a catch pan for proper disposal and refill according to manufacturer specifications.

Step 5 - Replace the Sparkplug

Replace the spark plug every season. Remove the sparkplug wire and loosen the plug with a socket wrench. Gap the new sparkplug according to manufacturer specifications using a gapping tool or feeler gauge. Replace the plug by hand and tighten it down, being careful not to cross thread it.

Step 6 - Replace the Air Filter

Check manufacturer specifications before purchasing an air filter. To change it, loosen the filter cover and remove the old filter. If the lawn mower requires a foam filter, it must be saturated in oil and the excess oil wrung out with a clean towel before it is installed. This is not necessary with a cartage filter. Replace the cover after installation and check that it has a tight seal.

Step 7 - Gas Replacement

Before storing the lawn mower, add a gas stabilizer to the gas tank and top off with gas. This will prevent dry rot and tarnishing. If a stabilizer was not added last season, drain old gas and replace it with new.