Who Manufactures Harley Davidson Spark Plugs?

Harley Davidson motorcycles may be iconic, but the company doesn’t manufacture all of the parts that go into them, such as spark plugs.

If you’re looking to upgrade or replace the spark plugs on your Harley, be sure to choose a trusted brand. But who manufactures Harley Davidson spark plugs? 

Harley Davidson spark plugs are manufactured by some big names, like, NGK, DENSO, E3, Champion, Screamin’ Eagle, and Gold.

Now, let’s explore these companies more deeply to enhance broad knowledge of their spark plugs. We’ve also included cleaning tips for your convenience.

Top Manufacturers of Harley Davidson Spark Plugs

Harley Davidson motorcycles use spark plugs to help ensure that their vehicles run smoothly. The company selects spark plugs based on factors such as performance, reliability, and durability.

However, according to a report by Allied Market Research, the global spark plugs market is expected to grow at a compound annual growth rate of 5.1% from 2021 to 2030, worth 5.3 billion. And the companies we’ll discuss today have the most contribution to this industry.

NGK (Iridium)

Japanese company NGK has been in business for over 80 years. You probably know that iridium is one of the most precious metals on earth. And surprisingly, their plugs are made with an alloy iridium tip, a core wire electrode, and a core of copper.

They boast an electrode that is 25% smaller than platinum and is one-fourth the size of a typical nickel electrode. Typically, iridium plugs are dual-cam, giving up to 3 HP gain, with the new metal coating of the housing improving its anti-corrosion qualities.

Plus, due to the high melting temperature of the nickel electrodes in these plugs, they have exceptional thermal resistance qualities.


Champion is the maker of high-quality spark plugs. The company has been around for over 110 years, and it serves the market with spark plugs that fit a variety of two-wheelers.

In addition, their spark plugs are perfect for Harley Davidson as they’re made with thermal bonding and nickel alloy electrodes to form a wider, longer insulating base and tip.

One of the things that set them apart is their 8 heat rating, which means they can handle a lot of heat without failing. And when it comes to installation, you won’t have any issues either, as they have a standard 12mm thread and a 5K Ohm resistance. So, they should fit right into your bike.


Spark plugs from E3 are known for giving your bike more power, better fuel efficiency, and less highly polluting emissions. They fit in modern Harley Davidson bikes, and they’re remarkable for their ability to give you great acceleration.

Diamond electrodes are used in E3 spark plugs to improve ignition. When the igniting period starts, the wave leaves the spark zone quickly to deliver consistent chimney impact to the engine.

For instance, the 12mm reach E3.36 spark plug that comes with a gasket seat design. It’s perfect for the FLHXS Street Glide, along with other 12V systems like UTVs, ATVs, and motorbikes.


It’s a Japanese manufacturer that specializes in automotive parts and systems. And did you know that the first spark plug to use iridium was made by DENSO?

These days, DENSO spark plugs are some of the most popular and widely used in modern engines. They’re especially known for their high-tech design.

One of their fancy technique is called 360-degree laser welding, which makes their plugs extra strong and reliable.

Screamin’ Eagle

The spark plugs from the company Screamin’ Eagle are designed to improve performance and increase longevity. They have a dual platinum coating that helps to prevent erosion and the “V” trimmed ground electrode reduces the chance of covering the flame side.

Their spark plugs also have a delicate wire core that helps with starts and ignition power. Plus, they’re made with technology that stops them from making too much noise or messing with other devices, such as radios.

Moreover, the fouling-resistant ribbed core technology allows them to work well in racing situations where a lot of air and fuel mixture is needed. Screamin’ Eagle spark plugs are a great choice for modified engines too.

Gold Plugs

“Gold” company produces spark plugs that feature a special housing liner and thread for quick removal of aluminum heads. These spark plugs feature a gold-palladium coating that helps to prevent corrosion.

Also, they have a tapered tip that provides better coverage for the spark from the air and fuel mixture, as well as smooth flow through the gap zones for optimal ignition.

In addition, their plug has a ground electrode with a copper core that operates at a lower temperature, helping to extend the lifespan. The insulator tip and narrow radius of the electrode wire in the middle also help to resist fouling.

Harley Davidson Spark Plugs

Oh! We can’t ignore that Harley Davidson offers their own spark plugs. Not only do these spark plugs provide a perfect fit, but they also work well on modified engines. Plus, the Harley Davidson original equipment spark plugs are sold in pairs, so you can easily replace both spark plugs at the same time.

Note: Some say HD does not make their spark plugs rather they rebuild them.

Frequently Asked Questions (FAQs)

When should I change my Harley Davidson spark plugs?

It depends on your model as well as the distance you traveled. However, you can change the spark plugs after riding 15,000 to 16,000 miles, which is often recommended to avoid engine disturbance.

How can I tell if the spark plugs in my Harley Davidson need to be replaced?

If you notice a lack of power while riding, running very poorly, and frequent stalling when trying to start up, it’s time for the replacement of the spark plugs.

How many spark plugs are there on a Harley?

A Harley Davidson normally has 2 spark plugs. But some advance engine comes with 4- two on the right and two on the left side.


Harley engines can rev up and put a lot of strain on the spark plugs, so make sure you have ones that can handle the power and heat. And you must keep checking on the plugs now and then to get a smooth and powerful ride.

Now, that you’ve discovered who manufactures Harley Davidson spark plugs, you can get any one of them and replace the old one whenever needed. Ride safe!

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