Introduction: How to Change Lawn Mower Oil

Picture of How to Change Lawn Mower Oil
This article and its video explain how to change lawn mower oil on most mowers, and how to change oil filters on mowers that have them.

The small engines that run lawn mowers need their oil changed just like car engines. Most mower engines need their oil changed every 20-50 hours of operation.

A mower's owner's manual will indicate how often to perform oil changes on the mower. At the very least, an oil change should be done annually with other seasonal tune-up maintenance.

This article explains the steps for changing oil in most mowers. Changing mower oil is very simple and can take as little as five minutes.

Step 1: Prepare for the Oil Change

Picture of Prepare for the Oil Change
There are a few things to do before removing the old oil from the mower.

1. Warm up the engine

Warming up the mower engine will speed up the oil change because the oil will flow more freely. It will also be a little easier to get all of the old oil out of the engine.

2. Clean around the oil fill area.

Use an air compressor or a clean towel to clean up around the oil fill area

3. Prepare an oil pan to catch the oil.

You'll need an oil pan or something similar to catch the oil from the mower. Position the pan on the side of the mower towards which you will tip it to drain the oil.

Step 2: Dump the Old Oil

Picture of Dump the Old Oil
Now with the prep work done, the mower should be ready to have its oil drained.

4. Remove the oil fill cap.

5. Tip the lawn mower on its side to drain its oil.

It's a good idea to leave the mower resting on its side for about a minute while all of the old oil drips out.

Tip Lawn Mower 

Step 3: Replace the Oil Filter (if Applicable)

Picture of Replace the Oil Filter (if Applicable)
The majority of walk-behind lawn mowers do not have oil filters, but several models on the market include them in the engine design. We've included the steps for changing a mower's oil filter below in case your mower model includes one.

If your lawn mower engine model does not include an oil filter, skip to step Step 10 to complete your oil change.

 

6. Prepare something to catch the oil.

Unscrewing your mower's oil filter will spill the oil it is holding inside of it.

Container to Catch Oil

Find something to catch the oil that is small enough to fit under the filter as you unscrew it.

Postion Container

 

7. Unscrew the old filter.

The old filter simply unscrews.

8. Coat the seal of the new filter with oil.

The seal of the new oil filter needs to be coated with oil before it is installed.

Using your finger, apply a small coat of motor oil to the outside lip of the new filter. This thin coat of oil will ensure that it seals tightly when you install it.

9. Install the new oil filter.

Screw the new oil filter into place until it touches the plate it seals against. Then, give the filter a firm 1/4 or 1/2 turn to tighten it down.

Step 4: Refill Mower Oil

Picture of Refill Mower Oil
Now the mower is ready to have its engine oil refilled. Remember that over-filling the oil on a lawn mower engine is just as bad as under-filling it.

Check the mower owner's manual for the exact quantity of oil that the mower takes.

Use the mower's dipstick as the final judge on the right oil level. Most mowers take between 2/3 and 3/4 a quart of oil

10. Add engine oil gradually until it is full.

Fill Engine Oil

Stop a couple of times as you fill the oil to check its level with the dipstick.

Creeping up on the "full" line like this reduces the chance of overfilling.

11. Replace oil cap.

Your lawn mower oil change is now complete.

Conclusion

Changing your lawn mower's oil will help its engine run powerfully and dependably. This and other simple equipment maintenance will greatly extend the life of your tools.

eReplacementParts.com can help you with your lawn & garden machine repairs. Visit our Lawn Mower Parts page to shop for parts by mower brand, or visit our Small Engine Parts page for more small engine maintenance parts.

Comments

perryrs1 (author)2015-07-15

What about removing the drain plug from under the deck???

SyliviaA (author)perryrs12017-07-12

Many new mowers no longer have a drain plug under the deck unfortunately.

sopromondo (author)SyliviaA2017-11-16

Funny I spent 10 minutes looking for a drain plug on my self propelled TORO, since my last lawnmower had one under the deck. Well I finally gave up and asked my brother for advice and he suggested exactly what is described in this article. The only drawback with this method is that oil tends to get in the combustion chamber resulting in a puff of smoke (pollution) the next time I start it.

Just want to point out that I hadn't changed the oil in 4 years since I bought it (don't know how I forgot as I am usually pretty good) and boy was the oil black and dirty. Had to flush it about 5 times (starting it between changes and letting it run for a minute or two) before the oil started to drain clear. I used synthetic oil as it's the only oil I use for all my 4 stroke combustion engines.

cgarriga5 (author)2016-05-14

Great! Easy to follow and understand instructions.

thedarnoc (author)2015-02-15

Nice guide. Looks like it was taken from here: https://www.youtube.com/watch?v=6uYAeK34veo

stringstretcher (author)2013-04-25

Good guide. Thanks

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