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How to Change Your Riding Mower's Oil

Riding lawn mowers can make maintaining your grass a breeze, but with this convenience comes crucial maintenance. Making sure that your riding mower has fresh oil goes a long way in keeping your engine running smoothly for a long-lasting life. Oil works to keep your engine lubricated and prevents overheating, so you can make sure your lawn looks better than ever with every cut. Checking and replacing oil doesn't take long, and it can help save you from the headache of costly repairs down the road.

Check your oil before every use. If the oil has turned black, it's time for a change. Consult your owner's manual for more information on how often you should change your oil. You should plan to change the oil at least once every year, ideally at the beginning of spring to ensure smooth operation through the season.

What you'll need:

Step 1: Figure Out How Much and What Kind of Oil You Need

Determine the appropriate API gravity of oil your mower will need. This is a measurement of how heavy an oil substance is compared to water. If your mower will be exposed to freezing temperatures before your next oil change, use 5W-30. If you plan to change your oil again before temperatures drop below freezing, or if you live in an area where temperatures rarely get that low, use SAE 30. Determine your mower's oil capacity using your owner's manual.

Step 2: Park the Mower on a Flat Surface and Warm Up the Engine

Set your mower on a flat surface away from sewer drains or plants before you change the oil in case there are any leaks. You'll have an easier time changing the oil if the engine has been warmed up first. Run the engine for 5 minutes while in park. 

Note: Make sure the engine is off and the key is removed from the ignition before you open the hood. Put on a pair of work gloves to help protect your hands while working with the engine.

 

Step 3: Remove Debris from the Engine Area

Prevent potentially damaging debris from getting into your engine. Make sure the hood, engine cover and screen are free of dirt, leaves or grass. Use a rag to brush these areas clean if debris is present.

Step 4: Disconnect the Spark Plug

Locate the spark plug near your engine. There will be an attached wire with a rubber boot connected to the spark plug. Detach the rubber boot from the spark plug so that the wire and spark plug are disconnected.

Step 5: Be Ready to Catch Old Oil

The last thing you want is for hazardous oil to seep into your beautiful lawn or enter any sewer drains. Put down a large sheet of plastic or cardboard directly under your mower's drain valve to catch any spills or drips, and then place a drain pan with a capacity that matches or exceeds your mower's oil capacity on top to catch the majority of the liquid.

Step 6: Remove the Old Oil

Open the drain valve. If your mower has a drain tube, place one end into the drain valve and the other directly into the drain pan. Press in the valve and turn counterclockwise with your hands or a pair of pliers to unlock. Pull it toward you to begin the flow of old oil through the tube.

The oil may take up to 10 minutes to completely drain from your mower's engine. Once empty, push the drain valve back in, and turn clockwise to lock. Remove the drain tube if present and place the cap back on the drain valve.

Note: Never discard old oil in any drain or in the trash. Set it aside, and bring it to an approved disposal site.

Step 7: Replace Your Oil Filter (if applicable)

If your mower engine has an oil filter, remove it. Pour any old oil into your drain pan and throw away your old filter. Use clean oil to lubricate the gasket in your new filter. Attach the new filter, making sure not to cross-thread it. When the gasket and the casing meet, turn the filter slowly by hand until firm.

Note: Be sure not to use a wrench or to overtighten, as this could cause damage to your engine.

Step 8: Add New Oil

Remove the dipstick and slowly pour fresh oil through the tube using a funnel. To prevent overfilling, check frequently to see how much you've added. Check your oil level by removing and wiping off the dipstick with a rag, reinserting firmly, and removing it again. Pour enough oil to get as close to the "FULL" mark as possible without going above the line.

Step 9: Finish Up

Replace the dipstick, wipe up any spills and reattach the spark plug wires. Now you can start your yard work with a healthy engine.