Tuning Up a Walk-Behind Lawn Mower

This video from Sears PartsDirect shows how to tune up your lawn mower. You should tune up your engine at least once a year to keep it running efficiently. Performing an engine tune-up includes changing the oil, oil filter, air filter, spark plug and fuel filter. We walk you through the process so that you can keep your engine in good shape.

Visit us at:

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

The video includes these parts and tools. Look up your model to make sure you get the right parts for your lawn mower.
Air filter
Spark plug
Spark plug wrench
Engine oil

Find parts for your lawn mower at:

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

In a well-ventilated area, check the fuel level. Drain the tank or run the engine till it’s nearly empty so fuel doesn’t spill when you tip the mower. Just before the oil change, run the engine for 5 minutes to warm the oil so it drains faster. If you ran the engine to empty the fuel tank, let it cool for about 20 minutes. The oil will still be warm enough. Put the mower on a level surface. Wearing safety goggles and work gloves, remove the fuel tank cap. Place a plastic bag over the fuel tank opening and put the fuel tank cap back on to prevent gasoline from leaking through the fuel tank cap vent. Remove the spark plug wire; be careful because the engine is hot. Remove the dipstick and wipe it clean with a shop rag. Put the drain pan next to the mower. Tip the mower to drain the oil from the dipstick tube and into the drain pan. After the oil drains, set the mower upright and wipe up any spilled oil. Carefully pour new oil into the dipstick tube. Start by pouring in three quarters of the amount of your engine’s oil capacity. Wait a minute for the oil to settle in the engine sump. To check the oil level, push the dipstick all the way into the dipstick opening and lock it. Then unlock and pull out the dipstick. If the oil doesn’t reach the top of the full mark on the dipstick, add a little more oil, wait a minute and check again. Repeat until oil reaches the top of the full mark. Reinsert the dipstick. Take off the fuel tank cap, remove the plastic bag and reinstall the cap. Next, we’ll change the air filter. Release the locking tab and pull off the air filter cover. Remove the old air filter and install the new filter. Reinstall the air filter cover. To replace the spark plug, use a spark plug wrench to remove the old plug from the engine cylinder. Using a gap tool and feeler gauge, set the gap on the new spark plug to the specifications in your engine owner’s manual. For this engine, the gap is 0.02 inches. Thread the new spark plug into the engine and tighten it with the wrench. Don’t reconnect the spark plug wire yet. The next step is to clean the engine when the engine and muffler are completely cool. Release the starter rope from the lawn mower handle. Remove the screws from the blower housing and pull the housing off the engine. Clean the muffler and engine cooling fins using the cleaning brush and shop rags. Also clean the choke and throttle rods, springs and linkages. Use the brush to remove debris from the rewind starter grill. You can blow debris and dirt off the engine and controls using compressed air. When you’re done, reinstall the blower housing and connect the spark plug wire. Reinstall the starter rope on the lawn mower handle. Now that we have everything installed, let’s start the engine and re-check the oil level. In a well-ventilated area, run the engine for a few minutes to move the oil through the engine. Then shut the engine off and allow a minute for the oil to settle in the engine sump. Remove the dipstick and check oil level. Add oil if needed to hit the full mark on the dipstick.

Leave a Reply

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