Skip to Content

How to change the oil in the Briggs and Stratton Lawnmower, step by step

An oil change is one of the most fundamental steps as far as engine maintenance is concerned. People tend to ignore oil changes for small engines such as those on lawnmowers. However, changing your oil at regular intervals can undoubtedly enhance your engine’s life and prevent you from unwanted engine problems such as an engine seizure. If you’re just wondering how to do an oil change for your Briggs and Stratton lawnmower, this blog post will help you with a clear step-by-step approach.

How to change the oil in the Briggs and Stratton Lawnmower, step by step:

  • Step 1. Prepare your Lawnmower
  • Step 2. Disconnect the spark plug cable
  • Step 3. Tilt the mower and set it up
  • Step 4. Drain the oil
  • Step 5. Replace the oil filter
  • Step 6. Check all the connections
  • Step 7. Add the new oil and test the engine

Gas Lawnmowers have relatively small engines compared with cars. Most recent models use a four-stroke internal combustion engine with a separate oil tank. This oil lubricates the engine’s moving parts, such as the pistons or the crankshaft. The lubrication ensures that the parts’ wear rate is minimized, thus enhancing the engine’s overall life. As a general guideline, oil changes should be performed at the start or end of every season. For walk-behind mowers, oil changes should be carried out after 50 hours of use, whereas for riding lawnmowers, you should change the oil after every 100 hours of use.

In more detail, I will explain the procedure for changing the oil on a Briggs and Stratton lawnmower.

Replacing the oil in your Briggs and Stratton Lawnmower:

Before replacing the engine oil, check your Lawnmower’s user manual. It should contain information about your mower’s various parts, including the oil drain plug’s location and the preferred oil and oil filter. Also, the typical oil quantities (48 ounces or 64 ounces / 0.35-0.4 L) will be mentioned. Briggs and Stratton lawnmower manuals are usually quite detailed and contain a lot of information that can help you.

Step 1: Prepare your Lawn Mower for the Oil Change

Ensure that you have the needed tools and products for the oil change, like new oil and a new oil filter. The tools you need are an oil pan, a screwdriver, a strap wrench, a simple wrench, some scrubs, and hand gloves.

Turn the engine on and let it run. A few minutes should be sufficient. This will raise the oil flow by warming it to a suitable temperature. Oil’s viscosity decreases with temperature, so removing it will get more comfortable. Avoiding this step will make it difficult to drain the engine’s oil, and the left oil residue may mix with the new one.

● Step 2: Disconnect the spark plug cable

Always disconnect the spark plug cables when working on a gas engine. This is a safety step to ensure that the engine may not start unintentionally. Turn off the ignition, separate the pull cord, and apply the parking brakes before you begin. Park your Lawnmower on an even hard surface that can deal with oil spills.

● Step 3: Tilt the mower and set it up

The next step is to tilt the mower. All lawnmowers have their oil drain at the base, while some have an oil dipstick at the top. So tilt the mower with support or lift it high enough using a lawnmower lift. Don’t forget to wear some safety gloves, as the oil can be hot.

● Step 4: Drain the oil

If your mower is one of those types with a dipstick, remove the dipstick before loosening the oil drain nut. This develops an air channel that will make draining the oil more efficient. Turning the blades and pulley to a side would be best before loosening the oil drain nut. Carefully remove the oil drain plug. You can use some rugs to protect you from sharp lawnmower blades. Turn the oil drain plug nut anticlockwise to open it. Ensure the drain pan is situated beneath the mower to collect the oil.

Always use safety gloves to keep your hands from getting messy from the crude oil and protect them from the hot oil. If you own an air pump, you can use this as an additional step to ensure that all the oil is drained. Use the pump to blow in the oil tank from the top. The air pressure will wipe away any oil residues left.

Step 5: Replace the oil filter

Some of the more recent lawnmowers have an oil filter. Some older models do not. It is recommended to replace the oil filter when you change your engine oil. If your Lawnmower does not have one, you can skip this step. Start with loosening the oil filter with the help of a strap wrench. When you are done loosening it, you can plug it out. The oil filter may hold some oil, so drain all the oil drops from it too. You can use the same drain pan to gather the trickling oil from the filter. Take a new oil filter and put on some oil on the top. This will make assembling the new oil filter easier. Fit the new oil filter, and make sure the oil filter seal remains intact.

● Step 6: Check all the connections

Check all the various parts for tight ensuring tight connections. The oil drain plug should be tightened properly. Remove the pieces of rug from the mower blades. Put the dipstick in your mower and remove the mower from the platform.

Step 7: Add in new oil and start the engine

According to the Briggs and Stratton lawn mower user manual, the refilled oil amount is typically 48 ounces or 64 ounces. The type of oil suggested for everyday usage is SAE 10W-30. Depending on your Lawnmower’s size, it may have two oil fill plugs (ordinarily yellow or white) on each side of the engine; either one can be used to fill the engine with oil to the correct level. Next, engage the spark plug and turn on the ignition. Let the mower breathe fresh air as the new oil circulates its engine. This will help it normalize.

While changing the oil, you must keep in mind your mower engine’s condition. Older and weaker mowers generally need thicker and more viscous oils like SAE 20W-50. If you are not sure, consult an expert.

The used oil should be disposed of according to local regulations.

Additional concerns:

To increase the lifetime of your Lawnmower and to ensure that the machine will start without problems, some precautionary measures are suggested:

  • Replace after 30-40 hours: Replace engine oil after 30-40 hours of use or usage in the first month.
  • Never use a non-detergent oil: A non-detergent oil can shorten the engine’s service life and hinder the machine’s functionality. 
  • Do not use 2-stroke oil: Avoid using oil suitable for a different engine type, like 2-stroke oil. It can damage the engine and cause a stalling issue. You must always use a good quality and brand-specific oil with no compromise.
  •  Flat surface: Whenever changing the engine oil, bring the Lawnmower to a flat surface. It will contribute to easing the task of oil changing.
  • Use Gloves: Use gloves while doing your maintenance work. It will prevent any personal damage from sensitive components or hot oil.
  • Disconnect the battery: Disconnect the battery’s power cable to avoid unwanted accidents like a short circuit.
  • Screwdrivers: Operate the screwdrivers carefully so that no wear and tear of screws occur. 

Frequently asked questions:

1. Which oil is best for lawnmowers?

The type of soil depends on the engine condition of your Lawnmower. It also depends on the working environment. In warmer climates for outdoor kinds of machinery, SAE 30 is your best option. In colder areas, you should stick with SAE 5W-30 motor oil. If you are in a place where the temperature fluctuates between 0° and 100° Fahrenheit, you should use an SAE 10W-30 motor oil.

2. Where is the drain plug located?

Look at the bottom of the engine body. Around the bottom, you should see a single bolt. That is your oil drain plug. However, the oil drain plug is located beneath the engine block near the crankshaft on vertical shaft engines. You will require a standard size 3/8″ ratchet and extension (no socket) to remove the square plug. A simple way to track the drain plug is to follow the oil tank and its curvatures to its bottom.

3. Is SAE 30 the same as 10w30?

No, SAE 30 is a single-viscosity oil. 10w30 is multiple viscosity. Recommended engine oil viscosity changes with temperature because natural oils change viscosity with temperature. An SAE 30 oil will thin out at higher temperatures.

Final remarks:

Replacing your engine oil can increase the lifespan and durability of your Briggs and Stratton lawnmower. It is suggested to check the quality of engine oil regularly. Old oil will increase the wear and tear of your engine and eventually even damage the engine. Changing the oil in a lawnmower is not a complicated job, and it should not take you more than 30 minutes. If you change the oil, always replace the oil filter if your Lawnmower has one. Hopefully, this blog gave you the user guidelines for changing the Briggs and Stratton Lawnmower oil.