Homeowner Helpers: Maintaining your lawn mower

Homeowner HelpersMaintaining your lawn mower means it’s safe, operates properly, uses less fuel and will last longer.

You could turn to a pro. But that will likely cost you up to $100 or more and you could end up waiting a week or longer because this is a busy time for repair and maintenance services. So why not do it yourself? It’s not difficult and requires only basic tools.

Start with your owner’s manual. It should tell you what needs to be done. If you don’t have the manual, use your model number to find it online.


Equipment and supplies for maintaining your lawn mower:

  • A socket wrench, spark plug wrench, screwdriver, locking pliers, drain pan, work gloves, spark plug, motor oil and fresh gasoline.
  • You’ll also need a metal file or grinder and a blade balancer (Home Depot sells a balancing and sharpening kit for around $15). If the air filter is dirty (and they usually are), you’ll have to replace or clean it; again, check your owner’s manual.
  • Your owner’s manual will also tell you what grade of oil you need and the spark plugs you can use.

Now you’re ready to start.

  • Safety first. Before doing anything, disconnect the spark plug to prevent an accidental start-up. Just pull the rubber cover off the end of the spark plug.
  • Empty the gas. If you still have gasoline in the tank from last summer, drain it. Old gasoline can foul the carburetor. Your owner’s manual should show you where you can do this. You can also turn the mower upside down and drain the old gas through the fill hole. Don’t throw the gas out — add it to your car: it won’t harm the vehicle.
  • Drain the oil. Most lawn mowers have a drain plug that you open using a Maintaining your lawn mowersocket wrench. You can then tip the mower on its side or empty the oil through the fill hole. The oil flows fast, so be ready with a container to catch it. Take the used oil to a recycling depot, which abound in Ottawa.
    Tip: Oil flows better if it’s warm — try leaving your lawn mower in the sun for an hour before working on it.
  • Replace the spark plug. It’s about the best $10 you can spend on your lawn mower because it ensures a fast start. Remove the old plug using a spark plug wrench or a socket. Tighten in the new one by hand and then snug it up using the wrench or socket. Don’t over-tighten.
  • Maintaining your lawn mower


    Blade balancer.

    Sharpen and balance the blade is an important step in maintaining your lawn mower. Dull or nicked blades can damage grass by cutting unevenly or even tearing shoots out, while an unbalanced blade gives an uneven cut and increases fuel consumption. Hold the blade in a gloved hand and use a socket wrench to undo the bolt securing it to the shaft. Sharpen the blade with a hand file, grinder or sharpener attached to your drill, maintaining the blade’s existing cutting angle. Check the blade’s balance using the balancer; if one end dips, you need to either replace the blade or remove more metal. Make sure the blade is well-tightened when you replace it and check tightness periodically over the summer.
    Tip: Clean caked grass from the undercarriage while the blade is off. A sharp, flat piece of wood works best and won’t scratch the undercarriage.

This video on  sharpening and balancing a blade applies to push and riding lawn mowers.



  • Final check. Clean debris from the top of the cutting deck, make sure the engine fins are clean of grass (the fins keep the engine cool), and clean up any spilled oil from the engine housing or elsewhere.
  • Add fresh oil and gas, and you’re ready to go.

Got a maintenance task you’re not sure how to do?
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