How to Check Spark Plug in Lawn Mower?

How to Check Spark Plug in Lawn Mower

The purpose of this post is to answer your question of how to check spark plug in lawn mower?

Approximately 80% of the houses in the USA have lawns. A survey suggests that adult Americans spent around 2.3 billion hours on lawns in 2014. That includes spending time on lawns and doing things to keep them in good shape. Maintaining a lush lawn takes a lot of your time and effort. And they don’t mind spending this much time here. Maintaining a lawn involves mowing, regular watering, aerating, and a few other practices. According to another survey, around 75% of Americans consider it necessary to spend time on their lawns. 

So, why do they love their lawns so much? What’s so special about these lawns? Why don’t people see lawns as just another piece of land? Why do they grow through so much hassle to maintain them? And last but not least, why are they willing to shell out their hard-earned cash on lawn care?

The answer is pretty obvious, i.e. lawns offer so many benefits. Most of these benefits are often overlooked, but we can come with many reasons why lawns are important for us. To keep things concise, we will not discuss all of them here. 

One of the most obvious benefits of having lawns is that they add to your home’s aesthetics. What’s more pleasing and welcoming than a lush green lawn at the entrance of your home? Not only do they add charm to your house, but also they increase its worth. They can increase the value of your home by as much as 15%. Long story short, lawns are a must for your home. 

Mowing is one of the most important practices that you can do to make your lawn healthy and attractive. For this purpose, you can use a lawn mower. Lawn mowers are an important tool in landscaping. They mow your lawn in no time and make sure you don’t put in a lot of effort. 

Now that we have discussed how important lawn mowers are, we will be talking about how to check spark plug in a lawn mower. Of course, knowing your lawn mower will help you take the maximum benefit and save you money and headaches. Knowledgeable landscapers have better lawns than those who don’t have enough knowledge of their equipment and tools. So make sure you read it till the end to know about spark plugs.

A spark plug is an important component in the engine of a lawn mower. Your lawn mower will do its job nicely when the spark plug is fine, but when it is worn out, your engine will either start improperly or won’t even start. It is responsible for igniting the combination of fuel and air, which is balanced by a carburetor. This whole process is necessary to run the engine. In this whole process, the spark plug acts as an ignition source. So when the spark plug is out of order, your engine will not start properly, and as a result, your lawn mower will start poorly.

Symptoms of a Worn Out Spark Plug

These are the symptoms that you may notice if your spark plug is damaged. Ensure you reach out to a mechanic or fix the spark plug immediately to save money and avoid inconvenience.

The first and most obvious symptom will be hard starting. When you have a tough time starting your lawn mower, the spark plug is the culprit more often than not. That is because of the weak spark that is created by the spark plug. If the spark is weak, it won’t ignite the mixture of air and fuel. So if it takes more than the usual time to get started, see if the spark plug is working fine. If you have a push lawn mower, you’ll have to go through many hassle by pulling the starter rope multiple times. Whereas, if it has a key start, it won’t start.

A bad spark plug also leads to bad engine performance. Firstly, it struggles to start. If it somehow starts, then it is very likely to shut down after some time. You’ll have to restart it again, but it will struggle even more to restart. It may even lead to the engine misfire in some cases.

A worn-out spark plug may cause more fuel consumption. Many lawn mowers run on gasoline. When your spark plug is not working well, you’ll notice that it is consuming more fuel than it normally does.

How to Check Spark Plug in Lawn Mower

How to Check Spark Plug in Lawn Mower

So, how to check the spark plug in the lawn mower? That may seem difficult, but you can do it easily by following these steps.

Start by removing the spark plug. You’ll have to remove the spark plug wire first for this purpose. Just pull it off the spark plug to remove it and move it away. 

Then you’ll need a wrench to loosen the spark plug. Get a wrench according to the size of the spark plug. Place it on your spark plug, and then use a turning tool with the wrench to loosen the spark plug. Keep turning the wrench, and the spark plug will be removed after a few turns. 

Once you’re done with removing the spark plug, you can examine it properly. You can see if it is damaged or not. 

Its look will help you find out whether it is damaged or not. It has a centre electrode that has a flat top when it is working well. If it seems rounded, it’s time to replace it. You can also see if there are any cracks on its porcelain sheath. If that’s not the case, but it looks black instead, then you should clean it. Thankfully, that’s as easy as pie. 

You can restore the spark plug by cleaning it with a soft wire brush. One thing to bear in mind is that if you use a hard brush, you might damage the porcelain insulator. Start with cleaning its outside edge first, and then keep turning it as you’re cleaning it. 


How do I know if my spark plug is bad?

There are several symptoms to watch out for that are associated with the worn-out spark plug. If your lawn mower struggles to start or shuts down after starting, it indicates a bad spark plug. Apart from that, more fuel consumption, the round top of the centre electrode, and poor engine performance are also symptoms. 

How long does a lawn mower spark plug last?

Spark plugs come in different kinds. The expensive ones last longer than the cheaper ones. However, on average, they last up to 25 hours. It means that you can use a lawn mower for roughly 25 hours with the same spark plug.


Spark plugs are an important component of an engine as they do the all-important job of igniting the mixture of fuel and air. A few symptoms are associated with damaged spark plugs, such as more fuel consumption, poor engine performance, and difficulty in starting. You can solve the problem by replacing it. Or if it looks black, you can fix it yourself by cleaning it with a soft brush.

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