Who Manufactures Harley Davidson Spark Plugs: The Best Brands

Harley Davidson manufactures its own copper and platinum spark plugs. They are popular, and many Harley riders prefer them for their originality. However, they don’t make Iridium plugs. So, other companies like NGK, E3, and Champion Spark plugs make them for Harley riders.

The curious rider often wonders who manufactures Harley Davidson spark plugs. You will find the answer to that in a while. 

More about Harley Davidson Spark Plug Manufacturer

Harley Davidson makes primarily three types of spark plugs.  These are the Original Equipment, Gold, and Screaming Eagle spark plugs. 

Original Equipment

The Original Equipment is the standard spark plug from the manufacturer. You will find them inside the majority of Harley bikes. Their prices start from $5. 

Gold Spark Plugs 

Harley Davidson Gold Spark Plugs
Harley Davidson Gold Spark Plugs

If you seek premium grade, go for Harley’s Gold Spark Plugs. They have longer lives and better materials than the standard version. Therefore, these spark plugs cost a few dollars more. 

Screaming Eagle Spark Plugs 

Screaming Eagle Spark Plugs 
Screaming Eagle Spark Plugs 

The best and the most expensive spark plug from Harley Davidson is the Screaming Eagle. Their engineering supports the highest RPMs and power delivery. You can get them for $23-$35. 

Other Manufacturers

All these are copper and platinum spark plugs. In comparison, the most advanced spark plugs are the Iridium ones. 

And since Harley doesn’t make those, they collaborate with companies that do. Examples include NGK, Denso, and AcDelco.

They have successfully manufactured iridium spark plugs for Harley Davidson Motorcycles for years.

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Materials And Technology Used In Harley Spark Plugs

Harley Davidson uses some of the best materials and technologies in their spark plugs. Nickel alloy and copper core, Gold Palladium, and Platinum are the material choices for Harley’s spark plugs. 

Nickel Alloy And Copper Core

The material and technology for standard Harley Davidson spark plugs are nickel alloy and Copper core. 

The central electrode of these spark plugs is made of copper. And as we all know, copper is highly efficient in conducting heat and electricity. However, it also tends to wear out faster. 

Thus the nickel alloy coating. It saves the copper electrode from fast decaying. Therefore, it makes a cheap but efficient spark plug with an average lifespan. 

Gold Palladium

These are a more advanced type of spark plugs. The central electrode has a gold-palladium alloy tip. Both gold and palladium are precious metals with excellent durability and conductance. 

A gold palladium spark plug lasts longer than the simple nickel alloy variants. They also save fuel and power since it requires less voltage to ignite. 

Plus, they have resistance to fouling. This means the spark plug’s performance will not easily diminish as it ages.


Another precious metal that helps increase the lifespan of spark plugs is Platinum. These spark plugs have a welded platinum tip on the central electrode’s nickel alloy base. 

Due to their sturdiness and high melting point, Platinum spark plugs can far outlast the average copper variants.

They’re also less prone to fouling and require low voltage to ignite. Harley also makes double platinum spark plugs. 

Here, the center and the ground electrode have a platinum tip. As a result, there is less gap erosion and far better performance.

Read Also: Harley Davidson Crotch Rocket: Truth Or Just Hype?

Where are Harley Davidson Spark Plugs Made?

Harley Davidson has strategically placed its factories all around the globe. There are three major factories where they make their spark plugs. 

In the U.S, these are – York, Pennsylvania, and Milwaukee and Menomonee Falls, Wisconsin. 

Outside the U.S., Harley Davidson makes its spark plugs in their Brazil, Thailand and India factories. But why did they choose to do that? Let’s consider their reasons- 

Reduce Production Costs 

The price of labor and materials is much lower in many countries outside the U.S. 

Setting up factories in these regions helps Harley-Davidson keep their production costs to a minimum. Plus, this allows them to sell their bikes at affordable rates. 

Avoid High Tariffs 

International authorities, like the EU, impose high tariffs on motorcycle products made in the U.S. 

One way to avoid these expenses is to produce the parts outside America. This is one of the reasons why Harley Davidson chose to open their Thailand factory in 2018. 

Cut down shipping and import costs 

Riders all around the world crave a Harley Davidson. But shipping and importing these products across borders requires high charges. 

Harley has cut down that cost by opening factories directly in foreign regions with high demand.

Read Also: Harley Davidson Drive Belt Replacement Cost : Unveiling The Price Tag

Top Aftermarket Spark Plug Manufacturers for Harley Davidson

Harley Davidson makes some of the best spark plugs for their motorcycles. However, they are not exclusively a spark plug manufacturer. 

Therefore, you will find better-performing and more affordable spark plugs from Harley’s various aftermarket manufacturers. 


When it comes to iridium spark plugs, NGK has almost no competitor. Their iridium spark plugs are cheaper than Harley’s advanced screaming eagle. Meanwhile, they deliver a much better ignition experience.


The company makes spark plugs with a central platinum and ground titanium electrode. 

These incredibly sturdy metals permit better ignition and acceleration. Denso also uses alumina powder as an insulator in its spark plugs. thus preventing overheating and fouling. 


If you want to stick with the good old Copper and Nickel Alloy, Champion spark plugs can be an excellent choice.

Their copper core electrode and nickel alloy center are of the highest quality. Therefore, last longer than other spark plugs that use the same material and technology. 


E3 is famous for its unique diamond-shaped electrode. This patented technology makes combustion more efficient. 

As a result, your Harley Davidson becomes a lesser threat to the environment due to its reduced carbon emission. 

AC Delco 

The iridium spark plugs from ACDelco can fit into the majority of Harley Davison engines. 

You will experience better fuel economy and more engine power with AC Delco’s plugs. Also, they have a fairly longer lifespan than the average copper or platinum variants.

Read Also: Harley Davidson Cam Tensioner Recall! Whether The Issue Is Ever Solved

How To Change The Harley Davidson Spark Plug?

You can easily change the spark plug of your Harley Davison at home. All you need is the owner’s manual and a few simple tools.

Step 1: Access The OId Plugs 

Use the owner’s manual to find your Harley’s spark plugs. You will commonly find them on the left of your vehicle. 

Depending on the model, your bike might have four or two spark plugs. You might have to remove the fuel tank to access the plugs. 

Step 2: Unscrew The Old Plug. 

Pull the old plug at its boot. Twist slightly to loosen it. Now use a spark plug socket and ratchet to unscrew it from the cylinder. 

Step 3: Check the Gap 

Before installing the new plug, check its gap. This is the distance between the center and the ground electrode. 

Ensure that the gap matches your Harley’s engine specifications. There are gapping tools you can use to measure and adjust the gap. 

Step 4: Insert New Spark Plug 

Insert the new plug and tighten it gently with your hand. Once it’s snugly fit, use a torque wrench to tighten it according to your engine’s torque requirement. 

Finally, push the spark plug wire to reattach. You should hear a click as the wire attaches. 

Lastly, re-install the parts you had removed to access the spark plugs. 

Read Also: Harley Davidson Production Number By Years: Evolution Of Harley


The discussion so far hopefully answered most of your Harley Davidson spark plug queries. But some questions might still need answering. Ask them here. 

How Long Do Harley Spark Plugs Last?

A normal copper spark plug can last anywhere from 15,000-20,000 miles. Meanwhile, advanced Iridium plugs can last for 50,000 miles. However, many riders don’t have to change iridium plugs until 100,000 miles.

When Should You Change Spark Plugs On A Harley?

Usually, you must change your Harley Davidson’s spark plugs every 20,000-30,000 miles. It depends on the type of spark plug you are using and your riding habits. 

How Many Spark Plugs Are On A Harley?

According to engine models, they can have two or four spark plugs. For instance, Twin Cam engines have four plugs. Meanwhile, the Evolution engine has two of them.

Final Words 

Knowing who manufactures harley davidson spark plugs helps you analyze options during a replacement. 

Remember, an advanced spark plug might cost you a few bucks more. But it also saves you from frequent replacements. 

Plus, in the long run, it increases the longevity and performance of your ride.

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