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How to Change Lawn Mower Oil: 7 Tips & Tricks

gardener using lawn mower

When was the last time you changed your lawn mower’s oil? A lot of people are very particular about their car engine oil and even have a fixed routine for changing it. But unfortunately, not many people pay attention to the oil in their lawn mowers.

All machines with moving parts need regular maintenance, which includes changing the oil. However, the process in a lawn mower is different from normal vehicles.

This guide will show you a step-by-step procedure that will teach you how to change your mower’s oil easily.

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Why Do You Need to Change the Oil in Your Lawn Mower?

Here are a few reasons why it is important to change the oil in your lawn mower:

  • To improve efficiency: Oil is required to lubricate the piston and other moving areas of your lawn mower. When the oil gets old, it stops performing its function—heat absorption and engine lubrication, thereby affecting the machine’s efficiency.
  • Increased longevity of the machine: By maintaining your machine, you are increasing its lifespan.
  • Security for the future: A lawn mower is a great investment. The machine’s resale value can be high when it is well maintained. Taking care of all parts of the machine, especially its engine, can guarantee you better deals if you ever want to resell.

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Oil Level of Lawn Mowers

The level of oil you have in your lawn mower is very important. It would be best if you tried to maintain balance while adding oil. It is dangerous to use your mower when the oil level is either too low or high.

Dangers of Underfilling
  • When there is insufficient oil, your machine will likely start overheating, which can cause further problems.
  • The moving parts of your machine will suffer some serious wear and tear.
  • When the oil completely dries up, the engine can suffer a knockout. Unfortunately, this usually requires a lot of money to fix, and sometimes, a knocked engine is beyond repair.
Dangers of Overfilling
  • It can also cause overheating. The crankshaft is unable to rotate freely when there is too much oil around it. This will increase its pressure and put some extra load on the machine’s internal parts, eventually leading to overheating.
  • When there is too much oil, it starts to overflow and wander into areas where it has no business being. When this happens, it will most likely end up in dangerous areas like the cylinder.
  • It can blow up the gasket.
  • Too much oil will produce smoke and release toxic substances into the atmosphere.

So, how can you know the right oil level to put in your lawn mower?

Green lawn mower inside a garage
Image By: bzzup, Shutterstock

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How to Check the Oil in Your Lawn Mower

The first thing to do is check the level of oil that is present in the tank.

Here is a detailed procedure:
  • Let the engine cool. If you have been running it, park it and allow it to cool before attempting to check its oil level.
  • Find the oil fill cap and open it.
  • Take the attached dipstick, clean it thoroughly and dip it into the oil tank, then cover the cap and leave it for a few seconds.
  • Bring out the dipstick and check the oil level against the minimum and maximum marks of the dipstick.

If the oil is below the minimum mark, it is too low. If it is above the maximum mark, it is too high. The best positions are between the marks.

Signs That Your Oil Needs Changing

Here are some signs that your oil needs to be changed:
  • Your machine starts overheating and producing a lot of smoke, which is likely an oil issue.
  • The mower suddenly starts making loud, cranky noises.
  • When the oil is no longer clear and you can see particles of dirt in it.
  • When the oil has lost its viscous nature and is now very light or very thick.
  • After using the dipstick to check the level of the oil, wipe the stick on a white piece of cloth to check the color.
lawn mower gas tank
Image By: mikhail62, Shutterstock

What the color of oil in your lawn mower indicates:

Golden or Amber Fresh oil. This oil is in great condition and does not require changing.
Milky white
Oil has been contaminated with water. If the water comes as a result of condensation, then as soon as the mower warms up, the color will change to normal. If the engine is warm and the color still hasn’t changed, the water might have found its way there from a faulty pump, the oil will need to be changed, and the machine will need to be checked.
Oil has taken on a lot of heat and soot particles and is in dire need of a change. When the oil turns black and thick, it has lost its coating ability and becomes useless.

How Often Should You Change The Oil In Your Lawn Mower

According to regulations, oil should be changed after it has been used for about 50 hours. This is relative to the frequency of use of the machine on your lawn. If you use your mower four times weekly, then it should be ready for an oil change after 3 months.

Also, it is good practice to carry out annual maintenance on your mower. Changing your oil will also be a great idea during this maintenance session.

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The 7 Steps on How to Change Lawn Mower Oil

1. Take safety precautions

This includes disconnecting the mower from any source of power. Do not take chances at all; simply cut out the power for a moment.

Also, ensure that you have all the necessary tools for this procedure within reach. For example, you will need an empty pan to collect the old oil, a socket wrench, an oil filter wrench, a funnel, and a new oil filter, if applicable.

2. Prepare the machine

Red Old mower in the garden
Image By: David Schwimbeck, Shutterstock

If the machine is small, you can prop it on a workbench to make the draining process easy. For larger machines, raise the mower until you can access the oil drain plug, which is located under the mower deck.

3. Warm up the engine for a few minutes

This will get the oil in a free state and make it easier for the old oil to flow out.

4. Take out the spark plug to get it out of the way

Changing lawn mower spark plug
Image By: The Toidi, Shutterstock

5. Remove the oil

Place the collecting pan directly under the drain plug and use the socket wrench to unscrew the drain plug cap by turning it anti-clockwise. Once it comes off, remove the drain plug, and the warm oil should easily flow out of the hole and into the pan.

Allow the flow to continue until the drain has been emptied. Then, you can tip the machine to the side to enable it to drain its content completely.

6. Clean the area around the plug

cleaning lawn mower with brush
Image By: FotoHelin, Shutterstock

A dirty oil tank can easily lead to rusting, hence, reducing the lifespan of the machine.

The oil changing session provides a great opportunity to give the area around the tank, the drain plug, and even the tank’s insides a thorough cleaning.

Once this is done, reinstall the plug.

7. Refill with new oil

Some oil tanks have pouring nozzles that make it easier to pour oil into the tank. However, if yours does not have one, a funnel can do the same job.

Pour the oil gradually, each time checking the level to ensure you do not overfill it. Once the mark is reached, take out the funnel and put the cap back on.

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What if Your Lawn Mower Has a Filter?

Some models of lawn mowers come with filters while others do not. If your lawn mower has a filter, and it is time to get it changed, you would have to unscrew the filter with the filter wrench after emptying the old oil from the tank.

There will be a little oil spill from the filter since a small amount of oil will be trapped in it, so be prepared for this. Take the new oil filter, apply a little amount of oil arousnd the outer part of the filter, and screw it into its new place.

After completing this, you can then proceed to refill the tank with new oil.

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Finally, you can start the lawn mower to inspect your work—the sound should be very good, and there should be no leakage. Changing the oil of a lawn mower is easy. With the right preparation and some level of determination, it will be done quickly.

The entire process should take about 15 to 60 minutes, depending on your level of proficiency and the type of lawn mower.

Featured Image Credit:, Shutterstock


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