Ultimate Lawn Mower Maintenance Guide

Ultimate Lawn Mower Maintenance Guide

Tips for Tuning Up Gas-Powered Mowers

We all maintain our health by getting enough sleep, exercise, and nutrition. Similarly, lawn mower maintenance is important for keeping your mower "alive" and able to give your lawn the perfect cut.


How to Do Maintenance on a Lawn Mower

Walk-Behind Lawn MowerMost lawn mower product manuals will include maintenance schedules that you can follow. The average residential mower might benefit from tune-ups three times a year, while some commercial mowers might need service after 25 hours of use (or sooner, in the case of oil changes).

To keep your lawn and your gas-powered mower in top shape, you must learn how to tune up a lawn mower. 

NOTE: Always refer to your owner's manual that came with your mower for proper maintenance procedures and specifications prior to conducting any lawn mower tune up work. 

Below is a list of simple lawn mower maintenance steps you can take throughout the year.


Fuel and Fuel Stabilizer

Refuel a Lawn Mower

Did you know that gasoline can go stale? After thirty days of sitting stagnant in your mower’s fuel tank, gas will have broken down into a gooey, acidic mess known as gum that can corrode your engine’s parts and clog your carburetor or fuel system.

We hope you drained your fuel before storing your mower for the winter. Even though some fuel stabilizers are designed for "storage," fuel still can go stale during winter storage. Leaving it in the tank isn't the best practice.

When you do fill your tank up with fresh fuel in the spring and throughout the summer, choose gas with the following characteristics to prolong your engine’s life:

  • An octane rating of at least 87
  • An ethanol content no higher than 10 percent

The jury is still out on whether gas with an octane rating higher than 87, also known as premium gas, will last longer. However, gasoline with these ratings is less likely to oxidize inside your fuel tank and wear away at your engine.



Oil Dipstick Check

Your engine's oil is one of the most crucial factors to keep your mower running. Using the wrong oil (weight and grade) at the wrong level can cause immediate, irreparable damage to the engine. 

The best time to check your mower’s oil level is when its engine is cold and the mower is positioned on level ground

In most cases, changing your oil after twenty-five hours of use is recommended. However, mowing in any of the following conditions might degrade your oil more quickly:

  • Dry, dusty ground
  • High temperatures
  • Wet or very tall grass
  • Steep grades or uneven turf

To make sure you’re operating with a proper amount of oil, check your level not only before your first mow of the springtime but before every time you mow


Oil Recommendation from Honda Owner's Manual

For most walk-behind gas lawn mowers, 10w30 weight oil will be an excellent choice. The API rating is also important. Look for an oil that features at least an SN rating, as oil with that rating is designed for improved fuel economy and engine protection.

Unlike checking the oil level, draining old oil is easier when your engine (and the oil) are warm, so run your mower for about fifteen minutes before the oil change to get the oil flowing and loosen any engine dirt it might trap.

When draining used oil, always be sure that the side with the air filter is facing up. You don't want dirty oil clogging the carburetor and ruining the air filter. Check out our small engine oil guide for more details.


Air Filter

Mower Air Filter

Your lawn mower’s air filter prevents excess dirt and debris from getting into the engine’s combustion chamber and interfering with its ability to generate power. It's a crucial, but sometimes forgotten step in lawn mower maintenance.

Like oil, air filters should be changed after twenty-five hours of use or three months, or at the start of spring, whichever comes first.

Mower designs vary, but your mower will use one of three kinds of air filters:

  • Paper air filter
  • Foam air filter
  • Dual element air filter (both paper and foam)

Always check with your lawn mower product manual for advice on how to change the filter and which replacement to use.

Also, be sure to remove the filter and knock out loose debris every time before and after you mow. Using compressed air to clean the filter is NOT recommended.


Spark Plug

Mower Spark PlugWithout a functioning spark plug, your mower’s engine has no way to ignite the mixture of gas and air that provides its power. You’ll notice some telltale signs of trouble if your spark plug is faulty:

  • Engine hesitates or is difficult to start
  • Engine starts but quickly cuts out
  • Mower consumes more gas than usual

Each year, spare yourself the hassle. Although the spark plug is yet another component that should be changed and properly gapped after twenty-five hours of use, we recommend, if nothing else, changing it as part of your annual lawn mower tune up.



Lawn Mower Blade Damage

We’ve seen any number of recommendations from different manufacturers as to when you should change or sharpen your mower blades:

  • Every couple of months
  • Every twenty-five hours of use
  • Twice per mowing season

The best advice we can give is to look at your blades at the same time you’re performing maintenance on other parts. Inspect them for chips, dings, or a thin, dull cutting edge.

Replacement blades are always available, and having an extra set on hand can make mowing all the more convenient for you each weekend. If your blades are still relatively new, they can be sharpened by running a long mill bastard file along each side’s cutting edge at an angle that matches the original bevel.

Be sure to sharpen both sides of the blade evenly to maintain your blade’s balance. Learn more about sharpening and replacing your mower blades as a regular part of lawn mower maintenance.



Clean Lawn Mower Deck

It’s not just about making your mower look pretty (although we do appreciate the smooth metallic shine of a well-kept piece of lawn care equipment). Cleaning the deck, which houses your lawn mower’s blade, provides several other benefits:

  • Removes debris that can cause your mower to rust
  • Removes fungal diseases and other lawn pathogens
  • Removes buildup that can reduce your mower’s efficiency

For your safety, clean the deck with the mower’s spark plug disconnected and the fuel tank drained. Turn the mower onto its side, and use a plastic putty knife to pry away large clumps of dirt and debris. Remove remaining debris by spraying the underside with a garden hose or a pressure washer. Allow the deck to air dry before reassembling your mower and starting to mow.

Riding Mower Maintenance Tip:

Lawn Mower Lift

The steps above cover maintenance tips for gas-powered push mowers. Maintaining a riding lawn mower, such as a lawn tractor or zero turn mower, is generally similar except for one major difference:

You need to take extra caution when lifting a riding mower.

To change the blades or clean the deck on a zero turn or another type of riding mower, your safest option is to raise it using a specially designed lawn mower lift. This will raise your mower and securely hold it in place while you perform your tune-up.


Mow Through Any Season

It’s true – many of these lawn mower tune up steps, such as changing your spark plugs, are just as easy to take before mowing for the first time each spring as they are before putting your mower away for the winter.

Any time is a good time to make sure that your mower is running smoothly. By regularly performing lawn mower maintenance, you’ll always be ready to transform your yard into a space where you can walk, sit, and enjoy your time.

It takes just a few simple steps to get the most out of your lawn – and your lawn mower – all year round.

NEXT: How to Store Your Mower for the Winter

Dale, the Power Equipment Expert
Power Equipment Expert
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