How To Check the Dirt Bike Spark Plug?

Owning a dirt bike gives you lots of experience in dealing with different kinds of issues. I am sure you would have faced spark plugs issues too. So how to know if your dirt bike spark plug is bad and needs to be changed. It is the most important factor for a professional dirt bike rider to know how to test a dirt bike spark plug.

Due to getting older a bike needs maintenance and hence several parts also need replacement. In this post, we are going to discuss how to make it possible to check the spark plug.  So hold tight and get ready to dive in for learning about the dirt bike spark plug.

How to check the spark plug?

A spark plug is made up of metal and insulating material so insulating material is for thermal as well as electrical resistance, at the top is the terminal which is connected to plug cap and ignition system then it is a rib or body of a spark plug, then at the bottom, there are threads which help you to screw the spark plug inside the engine block then there is a ground electrode or you can say the tip or the central electrode.

Also, you can see the air gap between the ground electrode and the central electrode. The air gap between the ground electrode and the central electrode is around 0.7 t0.8 mm. When the air gap is disturbed then the fuel economy decreases it starts misfiring.

Basically it does not run smoothly, so the terminal is connected to high voltage from the ignition coil or magneto. So this is all about the construction of spark plug so the terminal is connected to a high voltage supply and the voltage is passed through the central electrode and the gases which are in between the central electrode and the ground electrode gets heated or gets ionized and as they get ionized they start conducting the electricity and this is the time when ignition happens.

After removing it, you want to inspect it to check the colouring of the plug to see how your motor’s running. If it’s brown, it’s normal. If it’s a greyish-white colour, it will be too lean, and if it’s a dark colour and it smells like fuel, it’s too rich. And then, if it’s broken or chipped up, it usually means pre-detonation.

After you’re done inspecting it, you can either put it back in or you can replace it with another one. The reason you should check the spark plug is so you can see if it’s running rich or too lean so you can know if there’s going to be any more damage to the bike. You can check further on the bike and see if there’s any damage. If it’s brown; it’s O.K. and you’re good to go.  The other dirt bike issues like sputtering, leaking oil, and bogging can also make you feel helpless if you don’t learn about them.

Why does my spark plug shock me?

Dirt bike spark plug wire giving shock means the wire which is connected to it has too much resistance. It will be good if you replace all the wires with the new one. The reason for shock also is crack on a wire so you only need to replace all the plug wires and all the spark plugs.

How to Check For Spark Plug Fire

The first thing you can do is remove the spark plug boot that is on the top of it and you’re going to unscrew the power plug. After you remove the spark plug you just check if it is nice and clean and if it’s not damaged.

Then connect it with the spark plug bolted to make your test so what you’re going to do you’re going to place the spark plug next to a metal part of your engine or of your dirt bike. So what you’re going to do you’re going to find the way to press the power plug against ahead or any metal part of your dirt bike.

At that point, you’re going to try to turn on the engine of your bike. If your engine is with the kick start or the engine with the starter. With a kick start, you might need somebody else to help you out with the starter to do the test but if you have the starter engine with the scooter you’re just going to crank your scooter.

See if the bike gets started and gives a little spark, even a spark to the spark doing this way you can check if your spark plug has a spark. At that moment it looked like a disco der with the plug as a spark. so in this way, you can see if the problem was the electrical problem or we have a problem with the flow of the gas.

How to Clean Spark plug?

How To Check the Dirt Bike Spark Plug?

Firstly you need to disconnect the ignition cable. A clean spark plug will not only improve the performance of your dirt bike but also it improved efficiency. To clean the dirt bike spark plugs, first of all, you need a plastic cup to take the Petrol, a retired toothbrush, a Polish paper and the last thing required is the spark plug gauging – this is nothing but you know used to check the gap between the electrodes of it.

Now take a small amount of petrol to clean the spark plug. There are various methods of cleaning the spark plug. The reason why we choose petrol is that petrol helps to dissolve carbon easily into it. So since we have petrol now dip the spark plug into it. So if you look carefully the color of petrol will start changing the carbon will be dissolved into petrol and it’s becoming darker and more intense.

If there is a huge difference between the color of petrol and the indication, that means the carbon is getting dissolved. This doesn’t mean that it will remove all of the carbon, you can use a plastic or a steel bristle brush to remove the hard carbon.

The last thing you have to do is use sandpaper or a back polish paper to clean the hard carbon between the electrodes. This will make your spark plug shine like new. So once it is clean, make sure to check the gap between the electrodes.

You can use a spark plug gauging tool to check the gap. You can also refer to the manufacturer manual to see how much gap is required. Make sure you clean that fitting space before you fit your spark plug back.

A clean spark plug will not only help you to improve the acceleration but it also has some other benefits such as you’ll have a smooth start, we’ll have less vibration, you’ll see improvement in the fuel economy, you will have no misfiring and no smoky exhaust. Lastly, connect the ignition cable back to the spark plug and you are done with the process.

How to change a dirt bike spark plug?

The first thing you need to do to take off the spark plug on a dirt bike. There will be a rubber piece just give a little pressure push it up, it’ll come right off. Now you need a 13 over 16 lost- end wrench and just loosen it because as soon as it gets loose, it moves and spins with your hands. After losing it with a wrench, take your fingers and just twist.

Now take out the spark plug from your dirt bike. Now what you’re gonna do is take your new spark plug and place that in there and just screw it on with your hand all the way down.

How To Check The Dirt Bike Spark Plug

Now the key you have to switch over to close with thirteen / sixteenth wrench and you’ve to tighten this all the way down and do not go extremely hard, it’s gonna be difficult with the new metal gasket but if you go too much you’re gonna damage the spark plug because that is fragile ceramic and you really don’t want to break.

Now take the rubber hose thing and place it right on top, it might be a little difficult but put on top and then wait for a click. Now what you can do is you can start the bike up and ride.


Spark plugs are one of the most important parts of the dirt bikes and it needs to be tested regularly. But there are some symptoms that can easily give you clear indications that your dirt bike park plug is bad and it needs to be changed.

So I think after reading this article you have understood how to test the spark plug and what are the symptoms through which you can easily understand that your spark plug needs replacement. If you like this post then subscribe to our newsletter.