Socket Size Used For Lawn Mower Spark Plug

What Socket Size Is Used For A Lawn Mower Spark Plug?

Taking good care of your gas powered lawn mower is essential if you want it to perform well. There are some parts of your mower that need to be regularly replaced and that includes the spark plug.

Spark plugs are a vital component in your lawn mower’s engine. Without them, the fuel could not be ignited and the engine just wouldn’t start. Every few weeks, you’ll need to take the spark plug out to inspect it, clean it, and potentially replace it. But to do this you’ll need a spark plug socket. This leaves you wondering what’s the correct socket size for lawn mower spark plugs?

The right socket size will largely depend on the brand of lawn mower you are using. This guide tells you what size you’ll need for the most common types of engine and how to change your spark plug quickly and easily.

In the world of lawn mowing there are lots of manufacturers competing for your attention. However, when it comes to engines, there are a few that really stand out from the crowd. While there are other engine manufacturers out there, Briggs and Stratton, Honda and Toro are among the most popular. Here come details on the right lawn mower spark plug size for each of them.

Briggs and Stratton

If you’re using a Briggs and Stratton lawn mower or engine then you will need a spark plug socket that’s 13/16” or ⅝”.


Exactly the same as the previously mentioned B&S engine, if you have a Toro then you’ll need either a 13/16” of a ⅝” spark plug socket.


For those of you with a Honda lawn mower, you’ll need to specifically use a ⅝” spark plug socket.

How To Change A Spark Plug On A Lawn Mower

Socket Size Is Used For A Lawn Mower Spark Plug

If you are new to using a gas powered lawn mower then we must stress the importance of regularly checking, cleaning and replacing your spark plug. This isn’t a complicated job and is something you can do quickly at home. Of course, if you are in any way unsure, there are mower shops where you can take your machine to be maintained by a professional.

Here is how to change a spark plug on your lawn mower.

Disconnect The Spark Plug Lead

The first thing you will need to do is to disconnect the spark plug lead. Do this by removing the engine cover; note that not all mowers will have a cover.

You’ll see the spark plug lead connected to the spark plug itself. Do note that, if you are following instructions in your user manual, this lead may also be referred to as the ignition cable.

Remove The Spark Plug Using Your Socket

It’s now time to take out the spark plug and this is where your socket will come in handy. Make sure that you have chosen the correct size and then you can turn the socket in a counter clockwise direction. Sometimes, you may find that the plug takes a little effort to loosen but just take your time and potentially use a little lubricant to make it easier.

Clean The Spark Plug

Next, you will need to clean your spark plug. How long this takes and how difficult it is will depend on how dirty the plug is. However, using a spray cleaner with a wire brush can make the process a lot easier.

Inspect The Spark Plug

Inspect The Spark Plug

Now that the spark plug is clean, you’ll be able to get a better idea of its condition. You should make sure that nothing is distorted as well as checking for any visible damage. This might include cracking or burning. If you do notice anything, then you will need to replace the spark plug. Otherwise, you can go ahead and reinsert your existing one but be mindful to check it again down the line.

Adjust The Gap For The Spark Plug

Before you put the spark plug back into the lawn mower, you will need to adjust the gap that is between the curved and straight electrodes.

You can use a tool called a spark plug gauge which allows you to bend the electrode, making the gap the correct size.

Reinstall The Spark Plug

Finally, you can insert your spark plug back in or, if you’ve brought a new one, install this for the first time. Either way, the process is the same.

Place the plug into its appropriate location and turn it in a clockwise direction. Once in place and secure, you’ll use your spark plug socket to tighten everything up. If you previously removed an engine cover, then you’ll need to replace this before using the lawn mower.

Final Verdict

Spark plugs are an integral part of your lawn mower and without one, the mower will not work. However, you will need to clean and replace your spark plug from time to time and this requires the use of a spark plug socket.

While the size will vary according to the make of the engine, you’ll generally use either a ⅝” or a 13/16” socket. If you are unsure, you can refer to your user manual for more information.

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Andrew Fisher

Andrew Fisher

Andrew is a dedicated father of three who really takes pride in his lawn and garden. You'll find Andrew behind the scenes of almost everything Edge Your Lawn produces. When he's not helping readers find all the information they need, he's in his backyard working on his lawn and garden landscaping. This year he hopes to build an outdoor deck and sort out his veg patches.

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