How To Change Oil Lawn Mower Briggs And Stratton

Regular maintenance of your Briggs and Stratton engine begins with a proper oil change to ensure its longevity. Learning how to change oil lawn mower briggs and stratton is a straightforward task that any homeowner can handle with a few basic tools. This guide will walk you through the entire process, from preparation to the final check, ensuring your mower runs smoothly for seasons to come.

Changing the oil removes contaminants and worn metal particles that can cause engine wear. Fresh oil provides essential lubrication, cooling, and cleaning for the internal components of your Briggs and Stratton engine. Neglecting this simple task can lead to reduced performance, harder starting, and even costly engine failure.

By following these steps, you will complete the job safely and correctly. You will also save money on professional servicing and extend the life of your lawn mower significantly.

This section provides the complete, step-by-step procedure. Before you begin, ensure you have about 30 minutes of uninterrupted time and a flat, level workspace, such as a driveway or garage floor.

Gather Your Tools And Materials

Having everything you need within reach makes the job quicker and cleaner. You will not need any specialized mechanic’s tools for this basic maintenance.

Fresh Engine Oil: Check your owner’s manual for the correct type and volume. Most Briggs and Stratton engines use SAE 30 or 10W-30 detergent oil. Have a full quart on hand.
New Oil Filter (if equipped): Some models have a spin-on oil filter. Verify your model number to purchase the correct replacement.
Drain Pan: A shallow pan wide enough to catch the draining oil.
Funnel: For clean oil pouring without spills.
Socket Wrench or Adjustable Wrench: For removing the drain plug or filter.
Oil Filter Wrench (if needed): For gripping and turning a tight oil filter.
Clean Rags or Paper Towels: For wiping up drips and checking the oil level.
Gloves: Disposable gloves to keep your hands clean.
Safety Glasses: To protect your eyes from any splashes.

Prepare Your Lawn Mower

Proper preparation is key to a mess-free oil change and prevents potential safety hazards. Never attempt to change oil immediately after using the mower.

Run The Engine To Warm The Oil

Start the mower and let it run for 5-10 minutes. Warm oil flows out more quickly and completely, carrying more suspended debris with it. Ensure you are in a well-ventilated area.

Disconnect The Spark Plug Wire

This is a critical safety step. Locate the spark plug wire at the front of the engine and firmly pull the boot off the plug. This prevents the engine from accidentally starting while you are working on it. Secure the wire away from the plug.

Position The Mower For Draining

Move the mower to your level workspace. You may need to tilt it slightly to access the drain plug. If your model has a suction tube, you might not need to tilt it at all. Place your drain pan directly underneath the drain area.

Drain The Old Engine Oil

Now you are ready to remove the old, used oil. There are typically two primary methods, depending on your Briggs and Stratton engine model.

Method One: Using The Drain Plug

Many mowers have a dedicated drain plug on the side or bottom of the engine crankcase.

Locate the drain plug. It is usually a hexagonal bolt.
Using your wrench, carefully loosen the plug. Keep pressure on it as it loosens to control the flow.
Once loose, unscrew it by hand and quickly pull it away, allowing the oil to flow into your pan.
Let the oil drain completely. This may take several minutes. Tip the mower gently from side to side to encourage all the oil to exit.
Clean the drain plug and its threads with a rag. Inspect the washer for damage and replace it if necessary.

Method Two: Using A Suction Tube Or Tilt Method

Some walk-behind mowers lack a drain plug. Instead, you drain the oil by tilting the mower or using a suction tube inserted into the dipstick tube.

For tilting: Carefully tip the mower on its side, with the air filter and carburetor facing UP. This prevents fuel and oil from flooding these components. Let the oil drain out of the fill tube into your pan.
For suction: Insert a manual or pump-style suction tube into the dipstick tube. Pump or siphon the oil out into your container. This method can be less messy but may not remove all debris from the bottom of the crankcase.

Replace The Oil Filter (If Equipped)

If your engine has an oil filter, it should be replaced every time you change the oil. This ensures optimal filtration.

Place your drain pan under the filter location.
Use an oil filter wrench to loosen the old filter. Turn it counterclockwise.
Once loose, unscrew it by hand. Be prepared for oil to drip from the filter and the engine mount.
Before installing the new filter, dip your finger in the new oil and lightly coat the rubber gasket on the top of the new filter. This creates a better seal and prevents sticking.
Screw the new filter on by hand until the gasket makes contact. Then, tighten it an additional three-quarter turn by hand. Do not overtighten with the wrench.

Refill With Fresh Oil

With the old oil drained and the new filter installed, you can now add clean oil.

Locate the oil fill tube. It usually has a dipstick attached to the cap.
Insert your funnel into the fill tube.
Slowly pour in the recommended amount of fresh oil. Do not pour in the entire quart at once; start with about 80% of the recommended volume. Your owner’s manual states the exact capacity, often around 20 ounces for many push mower engines.
Wait a minute for the oil to settle into the crankcase.
Remove the funnel and wipe the dipstick clean with a rag.
Insert the dipstick fully, then remove it again to check the level. The oil should be between the “Full” and “Add” marks on the dipstick.
Add small amounts of oil as needed, checking the level each time, until it reaches the “Full” mark. It is crucial not to overfill, as this can cause engine damage.
Once filled, securely replace the oil fill cap/dipstick.

Final Steps And Cleanup

You are almost done. A few final checks will ensure everything is in working order.

Reconnect the spark plug wire by pushing the boot firmly onto the spark plug.
Start the engine and let it run for about a minute. This circulates the new oil throughout the engine. Listen for any unusual noises.
Turn off the engine and wait another minute. Check around the drain plug and oil filter for any leaks. A small seepage might just be residual oil; wipe it clean and check again after the next use.
Check the oil level one final time with the dipstick. Add a little more oil if the level has dropped slightly after circulation.
Properly dispose of the used oil and filter. Take them to an automotive service center, recycling facility, or parts store that accepts used oil. Never pour used oil on the ground or into drains.

Choosing The Correct Oil For Your Engine

Using the right oil is as important as the change itself. Using the wrong type can void warranties and harm engine performance.

Consult Your Manual: The owner’s manual is the definitive source. It specifies the oil viscosity (like SAE 30) and service classification (like SJ, SL, or higher).
General Guidelines: For most Briggs and Stratton engines operating in temperatures above 40°F (4°C), use SAE 30 detergent oil. For variable temperatures or if you use the mower in spring and fall, a multi-viscosity oil like 10W-30 is often recommended.
Synthetic vs. Conventional: Conventional oil is sufficient for most lawn mower engines. Synthetic oils can offer better performance in extreme temperatures and longer intervals between changes, but check your manual for compatibility.
Never Use Non-Detergent Oil: Modern small engines require detergent oil to keep internal components clean.

Common Mistakes To Avoid

Awareness of these common errors will help you complete a perfect oil change everytime.

Overfilling the Oil: This is the most frequent mistake. Excess oil can cause foaming, poor lubrication, and smoking from the exhaust. Always add gradually and check the dipstick.
Forgetting Safety: Always disconnect the spark plug. A accidental start-up with your hands near the blade is extremely dangerous.
Using The Wrong Oil: Do not guess. Find your model number and confirm the oil specification.
Not Changing The Filter: If your engine has a filter, change it with every oil change. A clogged filter restricts oil flow.
Improper Disposal: Used oil is a pollutant. Recycling it is easy and is your responsibility.
Overtightening The Drain Plug Or Filter: This can strip threads or crush gaskets, leading to leaks. Snug is sufficient.

When To Change Your Lawn Mower Oil

Sticking to a schedule prevents engine wear. Do not rely solely on the number of operating hours unless you have an hour meter installed.

First Change: After the first 5 hours of operation on a new engine. This removes initial break-in metal particles.
Subsequent Changes: Change the oil at least once per mowing season, even if you only used the mower a few times. Over the winter, condensation can contaminate the oil.
Heavy Use: If you have a large property or use the mower commercially, change the oil every 50 hours of operation or as specified in your manual.
Annual Check: Make the oil change part of your spring tune-up routine before the mowing season begins.

Frequently Asked Questions

How Often Should I Change The Oil In My Briggs And Stratton Mower?

You should change the oil at least once per mowing season. For new engines, perform the first change after 5 hours of use. Under heavy use, consider changing it every 50 hours. Always refer to your specific model’s manual for the manufacturer’s recommendation.

Can I Use Car Oil In My Briggs And Stratton Lawn Mower?

You can use automotive motor oil if it meets the service classification and viscosity specified in your mower’s manual (e.g., SAE 30, 10W-30 with an SJ or higher rating). However, oils labeled specifically for small engines are formulated for their unique operating conditions and are often the best choice.

What Is The Best Way To Drain Oil From A Lawn Mower Without A Drain Plug?

For mowers without a drain plug, the two most common methods are carefully tilting the mower on its side (air filter up) to pour the oil out the fill tube, or using a manual or pump-style oil extractor suction tube inserted into the dipstick hole to siphon the oil out.

What Happens If I Put Too Much Oil In My Lawn Mower?

Overfilling can cause serious problems. Excess oil can be whipped into foam by the moving parts, leading to inadequate lubrication, engine overheating, hard starting, and white or blue smoke from the exhaust. If you overfill, you must drain the excess oil to the correct level.

Do All Briggs And Stratton Engines Have An Oil Filter?

No, not all models have a replaceable spin-on oil filter. Many smaller engines on push mowers rely on a internal screen or slinger system for oil cleaning. Larger engines on riding mowers and tractors are more likely to have an external filter. Check your operator’s manual or look on the engine itself near the base to see if a filter is present.