Every mowing season starts with changing the engine oil in my push mower. I always choose to change my own engine oil because hauling my mower into the repair center, waiting a week, and picking it up takes up time I do not have.
Changing engine oil in your push mower is easier than you think. Not only do you get satisfaction when you’ve completed the project, but you also save time and money.
Engine oil in a push mower must be changed once a year or every 25 hours for most manufacturers. Oil in a new push mower engine must be replaced after the first 5-hour initial break-in period.
Changing the engine oil on your push mower is required to ensure your mower’s engine life is not shortened due to excessive engine wear. A push mower’s engine oil gets dirty over time and, without a filter, can cause contaminants to build up and wear on the engine.
Significant engine damage can occur if you don’t change your engine oil.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
How to Change the Engine Oil In A Push Mower
Step 1: Gather Tools
The best way to start this routine service is by making sure you gather the tools and supplies you need before you start.
- 1 Quart of Engine oil (SAE30 or Air-Cooled 10W30. Refer to your owner’s manual)
- Drain pan or another container to collect oil
- Socket wrench or set of spanner wrenches to fit the drain plug
- Rags or paper towel
- Rubber gloves
- Plastic funnel
- Cardboard, newspaper, or other product to keep from getting oil on your work surface
Step 2: Warm Up the Oil & Prepare Surface
Start the mower’s engine and let it warm up. Warmer oil will flow better than cold oil which allows you to get most of the oil to run out of your engine.
Because the engine is now hot, take extra precautions to not directly touch the engine to reduce burns and other injuries. Let the mower run for about 2 minutes and shut off.
While the engine is warming up, take this time to prepare the surface you will be using. Always use a hard flat surface. Cover the surface with cardboard, newspaper, or other material to prevent oil from penetrating your hard surface.
Step 3: Unplug the Spark Plug Wire for Safety
It is very important to unplug the spark plug lead from the spark plug before you begin working on your mower. You do not want to skip this safety step.
This step will prevent the engine from starting if rotating the blades happen to turn the engine over. The spark plug lead may come off hard, but it should come off with a twist.
Step 4: Place Your Mower on Its Side
Gently place the lawn mower on its side. When placing the mower on its side, try not to place the carburetor on the bottom. It’s best to keep the carburetor on the high side.
This will prevent the engine oil from running into the carburetor and the air filter.
Step 5: Remove the Drain Plug & Drain Oil
Look for a square or hex-shaped plug located on the bottom of the engine. This should be your drain plug.
You may have to scrape the grass out from underneath the deck first in order to find the plug. Unscrew the plug. It should be right-hand threaded so you will have to turn it counter-clockwise to remove it.
Some engines may have a plug at the bottom of the dipstick that can be removed to drain the oil. If your mower has this type of plug, you won’t have to turn the mower on its side to drain the oil.
Allow the oil to run out of the engine into an oil drain pan. While the oil is draining out of the drain plug, loosen the cap or dipstick, if available, to allow the oil to run out of the engine at a faster pace.
While the mower is still on its side, this is a good opportunity to scrape the old grass from under the deck and inspect your blades. You will want to make sure your blades are sharp and not damaged.
Doing this procedure will make sure your grass looks nicer the next time you mow. You can find out more about blade inspections and sharpening here.
Step 6: Replace Drain Plug & Return Your Mower to Upright Position
Install the drain plug back into the bottom of the engine by turning the cap to the right or clockwise to tighten it. Gently place the mower back onto its wheels and place it in the upright position.
Step 7: Fill with Fresh Oil & Replace Oil Cap
Place a funnel into the oil reservoir and add about 3/4 of a quart of engine oil. Check the oil level on the dipstick or according to your owner’s manual to ensure the oil level shows full.
Add more oil, if needed, to bring the oil level to full on the dipstick. Place your oil cap back onto your engine.
Step 8: Reattach Spark Plug Wire on Your Push Mower
At this time you can reattach your spark plug lead. You have completed your engine oil change.
How Often Do You Have to Change Your Engine Oil
You should change the push mower engine oil once per year and more frequently if used over 25-50 hours a year. This can vary by engine manufacturer.
One exception to the rule is if your mower is new or if you recently installed a new engine in your mower. It is important to complete your first oil change on a new engine after your first 5-10 hours of use.
This first oil change will remove all of the particles that may have been left behind from the manufacturer’s machining process.
These particles can be very harmful to the long-term life of your engine if you don’t complete this initial oil change.
Determine the Type of Engine You Have
Before you change your engine oil, you need to determine the type of engine you have. There are many different engine manufacturers on the market today.
You may have a leading brand engine such as Kohler, Honda, or Briggs & Stratton. You may also have an aftermarket, also known as a knock-off, engine using the design of an engine that used to be manufactured by one of the leading engineering companies.
You can usually find your engine manufacturer information located on a sticker on top of your engine.
Choosing the Right Kind of Oil
In most cases, your typical lawn mower engine is SAE30 blend or straight 30-weight.
However, Kohler engines will need an air-cooled 10W-30 because some of its internal parts won’t take the SAE blend very well. Always check your owner’s manual for the manufacturer’s recommendation for engine oil.
Always Recycle Used Engine Oil
Never dispose of used motor oil in your drain, dump it outdoors, or place it in a landfill with your daily trash as it can contaminate the groundwater. Used motor oil can be re-refined and resold as motor oil or used as other types of oil for heating.
According to the Environmental Protection Agency (EPA), re-refining used oil takes about 1/3 of the energy of refining crude oil to lubricant quality.
It also takes one gallon of used oil to produce 2 1/2 quarts of new high-quality lubricating oil. Compare that against needing 42 gallons of crude oil to produce the same amount of lubricating oil.
Gather oil in an approved sealed container. Place the used oil back in its original container. If you don’t have that container, use a polyethylene-sealed container.
Do not use containers not suitable for oil such as soda bottles and milk jugs.
Take used oil to your local recycling center. Check with your city to see if they have a curbside pickup program. Many auto store centers will accept your used motor oil.
Is Lawn Mower Oil the Same as Car Oil?
The old saying, “Oil is oil” is not true anymore. Keep in mind, you are working on an air-cooled engine unlike the one in your vehicle.
Your car depends on the liquid to cool it down while your lawn mower depends on air and oil to keep it cool.
Air-cooled engine oil has more cooling agents in it than your typical automotive oil.
Should I Use an Extractor Pump for an Engine Oil Change?
Using an extractor pump is an easy way to remove oil from a lawn mower engine. There are pros and cons to using a pump on a push mower. It’s a matter of preference.
A good extractor pump for this purpose can be found for $25 – $80 on Amazon or your local hardware or automotive store.
Traditional Drain Plug Method
Pros
- Extracting oil is fast
- Cheaper than extracting. No additional investment is needed for an extractor pump
- You may get more oil out of the engine
- Able to conduct other maintenance checks and procedures while oil is draining
Cons
- It is often a messy process
- You have to lay the push mower on its side
- Risk damaging the oil pan or drain plug
Extractor Pump Method
Pros
- Cleaner process
- No need to lay the push mower on its side
- No risk of damaging the oil plug or oil pan
Cons
- You may not be able to get all of the oil out of the engine
- Slower process to extract oil
Other Maintenance Items to Complete While Changing Oil
In addition to changing your engine oil, you should also complete the following when completing your annual service:
- Scrape the deck removing old grass and debris
- Inspect mower blades for sharpening or replacement. You can find more details here.
- Replace the fuel filter
- Inspect and clean or replace your air filter
Having Problems with Your Push Mower?
While regular oil changes can reduce problems that develop in your mower and extend its engine’s life when you own your mower long enough you’re likely to run into a few issues.
I’ve put together a guide to help you identify the cause of a mower problem. Read Common Push Mower Problems & Solutions next time you run into an issue.