How To Change A Spark Plug In Lawn Mower

If you own a lawn mower, it is essential to maintain it properly to ensure that it lasts longer and runs efficiently. One of the essential maintenance tasks is changing the spark plug. In this guide, we will discuss how to change a spark plug in lawn mower to keep it running smoothly.

Why Change a Spark Plug in Lawn Mower?

A spark plug is a small but critical component in the combustion engine of a lawn mower. It generates a spark that ignites the fuel in the engine, allowing it to run. Over time, the spark plug can become worn out, dirty, or corroded, which can result in poor performance, reduced fuel efficiency, and difficulty starting the mower. Changing the spark plug regularly can help to prevent these issues and keep your mower running smoothly.

When to Change a Spark Plug in Lawn Mower?

The frequency of changing a spark plug in a lawn mower depends on the type of mower and usage. As a general rule of thumb, it is recommended to replace the spark plug every 50 hours of operation or at least once a year. However, in some cases, it may need to be changed more frequently, such as when the mower is used in dusty or dirty conditions.

How to Change a Spark Plug in Lawn Mower?

Now that we know why and when to change a spark plug let’s discuss how to change a spark plug in lawn mower. Follow the steps below:

Step 1: Turn off the Lawn Mower and Disconnect the Spark Plug Wire

Before you begin, ensure that the lawn mower is turned off and the spark plug wire is disconnected to prevent accidental starting. Locate the spark plug wire and pull it off the spark plug.

Step 2: Remove the Old Spark Plug

Use a spark plug wrench to loosen the old spark plug and remove it from the engine. If you are unsure which size wrench to use, refer to the owner’s manual.

Step 3: Check the Spark Plug Condition

Inspect the old spark plug for signs of wear, damage, or corrosion. If the spark plug tip is covered in black soot or oil, it may be an indication of engine problems, and you should seek professional help.

Step 4: Check the Gap on the New Spark Plug

Before installing the new spark plug, check the gap using a spark plug gap tool. The correct gap is usually specified in the owner’s manual or on the packaging of the new spark plug.

Step 5: Install the New Spark Plug

Carefully thread the new spark plug into the engine by hand, being careful not to cross-thread it. Once it is finger-tight, use the spark plug wrench to tighten it to the recommended torque setting.

Step 6: Reconnect the Spark Plug Wire

Reconnect the spark plug wire to the new spark plug, ensuring that it is pushed on firmly.

FAQs related to How to Change a Spark Plug in Lawn Mower

1. Can I reuse an old spark plug?

It is not recommended to reuse an old spark plug as it may be worn or damaged, resulting in poor performance or difficulty starting the engine.

2. Can I change the spark plug myself?

Yes, changing the spark plug is a simple task that can be done by following the steps outlined above.

3. Can I use any spark plug in my lawn mower?

No, it is essential to use the correct spark plug specified in the owner’s manual or recommended by the manufacturer.


Changing the spark plug in a lawn mower is a simple but critical maintenance task that can help to keep the mower running efficiently and smoothly. By following the steps outlined in this guide, you can ensure that you change the spark plug correctly and enjoy a well-maintained lawn mower. Remember to check the spark plug regularly and replace it when necessary, and you’ll have a healthy and happy mower.