How to Tune Up a Lawn Mower

This video from Sears PartsDirect shows how to tune up your lawn mower. The engine on your lawn mower needs a periodic tune-up, just like the engine on your car. Tuning up your lawn mower engine at the start of each mowing season helps it burn less fuel and run more reliably. We’ll show you how to drain the fuel, replace the oil, remove and clean the mower blade, replace the spark plug, clean or replace the air filter and lubricate the pivot points for the engine control so that your mower will operate reliably and at peak efficiency.

Visit us at:

Or call 1-800-437-1673 to speak with a parts specialist.

The video includes these parts supplies. Look up your model to make sure you get the right parts for your mower.
Spark plug
Air filter
4 Cycle engine oil
Replacement blade

Find parts for your lawn mower at:

Or click here to schedule an appointment with a repair technician.

It’s best to tune up your mower’s engine once a year. The parts you will need to do the tune-up are a spark plug, an air filter and one quart of four-cycle engine oil. You can order these parts online by visiting or by calling 1-800-252-1698. In a well-ventilated area, start the mower and let it run for about 5 minutes. This will suspend any metal particles that have settled in the bottom of the engine. It also warms the oil so that it will drain faster. After the engine is warmed, stop the engine. With a gloved hand, remove the spark plug wire. Be careful, as the engine will be hot. To prevent gas from leaking when you turn the mower on its side, cover the gas tank with a plastic bag secured by the gas cap. Next, remove the dipstick from the engine and wipe the oil off the dipstick with a paper towel or a shop rag. Then place the dipstick in a safe place. Now, position the approved oil container next to the mower. Then, tip the mower so the dipstick tube is toward the ground. Be sure while you are tipping the mower, the oil is draining into the drain pan. While you are waiting for the oil to drain, it’s a good time to clean the underside of the mower housing. Remove the blade to prevent injury. You can use a putty knife to remove any grass buildup. While you’re looking under the deck, inspect the condition of the blade. If the blade is dull, nicked or bent, it should be replaced. Please see the PartsDirect video on how to replace a mower blade. Now, hold the blade against the blade adapter with one hand and thread the blade bolt with the other. Holding the blade with a gloved hand, tighten the bolt with a torque wrench. The blade bolt should be tightened between 450 inch-pounds minimum and 600 inch-pounds maximum. After the oil is drained, tip the mower back over. Pour the oil into a sealed container and dispose of it in accordance with applicable law. Most Sears automotive stores will accept used oil for recycling. Call your local Sears Auto Center for details. Be sure to wipe up any oil that may have spilled in the process. Now you will need to refill the engine with oil. Using a funnel, carefully pour the oil into the dipstick tube. Only pour in about ¾ of the amount recommended in the owner’s manual. Check the oil level with the dipstick and add as needed to reach the target level. Replace the dipstick and screw it on tight. Now it’s time to replace the spark plug. Use the spark plug wrench to remove the spark plug. The engine may still be warm. Before installing the new spark plug, set the spark plug gap to .030. Thread the new spark plug in by hand. Then, tighten it with the spark plug wrench. Next, replace the air filter. Remove the air filter cover with the correct size screwdriver. Once the cover is removed, discard the old filter. Before installing the new filter, use a clean rag or paper towel to wipe any debris out of the cover and around the air filter body. Once it’s clean, install the new filter, put the cover back on and replace the screws. Lubricate the pivot points for the engine control. Use a lubricating spray such as WD-40 on each side and work the lever up and down to ensure it moves freely. If you placed a bag under the gas cap, unscrew the cap and remove the bag. The last step is to reconnect the spark plug wire.

Leave a Reply

Your email address will not be published. Required fields are marked *