Best Spark Plugs for Harley Davidson in 2022 – Top 5 Picks

Best Spark Plugs for Harley Davidson in 2022 – Top 5 Picks

The best spark plugs for Harley Davidson are one of the most critical components that motorcycles’ engines depend on. They are responsible for initiating the combustion process. Since they provide consistent punches of electricity to start the engine, they wear and tear over time.

For this reason, it’s important to replace them regularly. But when your Harley Davidson’s spark plugs fail, you don’t want to replace them with average units. Instead, you should get the best spark plugs for Harley Davidson motorcycles.

Also Read: Most Reliable Motorcycle

These plugs need to have premium materials to help them maintain optimal engine performance. Besides performance, high-quality spark plugs for Harley Davidson can help to enhance the engine’s durability. Therefore, you won’t have to go through replacement processes often.

I’m a motorcycle enthusiast and have been in the industry for over a decade now. Therefore, I want to discuss what you need to look for when selecting the best spark plugs for Harley Davidson and also highlight the five best picks for 2022 and beyond. Keep reading to find out more about these spark plugs.

Top 5 Spark Plugs for Harley Davidson

NGK Iridium IX DCPR7EIX Spark Plugs – Best for Twin Cam

Durability and material

NGK is a renowned manufacturer of high-end spark plugs for all automobile vehicles. It infuses high-quality materials with a plethora of benefits. The core material of these spark plugs is iridium, and its electrodes are fine wire-centered. As a result, they are six times stronger and more durable compared to traditional copper electrodes.

Iridium alloy has a high melting point, making it suitable for Harley Davidson’s high-performance engines. When you install them, you’ll replace them again after traveling for around 100,000 miles.


Iridium designs these spark plugs and makes the electrodes so compact that they perform better under low voltage. Therefore, you’re getting enhanced engine performance and saving fuel. These spark plugs also cause Harley engines to have smoother idling and acceleration.


As NGK spark plugs are pre-gapped, you’ll need to assess the pre-gap size of the electrodes to install them. If it fails to match, you can seek a professional mechanic and have them installed, or you can customize them on your own.


  • Improve your engine’s speed
  • Support faster motorcycle starts
  • Long-lasting
  • Pre-gapped for convenient installation


  • Cost more than traditional spark plugs 


These spark plugs can fit in various Harley Davidson bikes. They’re versatile and pre-gapped, although you can change the gapping as you wish.

DENSO # 3297 Iridium LONG LIFE Spark Plugs – Best Overall


From the history books, Denso was the first manufacturer to produce iridium spark plugs to match high-tech engines. Presently, all spark plug companies have modified their plugs to match their customers’ demand for upthrust performance and durability.

In these spark plugs from Denso, you’ll find a 360⁰ laser-welding process. This protects the plugs’ electrodes from breakage or wearing even when you encounter the toughest driving conditions.

Denso patented the design of their spark plugs both in the US and Japan. It’s the most recommended brand for modern bike engines, like the Harley Davidson.


After understanding Denso’s history, you may have realized how reliable its performances are. The fusion and condition of this technology offer unrivalled performance and dependability to your motorcycle.

These spark plugs for Harley Davidson bikes offer better fuel economy, greater acceleration, and a powerful engine that doesn’t misfire, so you can enjoy longer distances without facing any hurdles.


  • Made from iridium which improves their durability
  • Offer improved fuel economy
  • Have 360⁰ laser-welding
  • The electrodes can survive in extremely harsh conditions


  • Pre-gaping may require some readjustments


These spark plugs from Denso can fit into most Harley Davidson motorbikes. They can fit any bike because they are tailored to fit all modern, high-performance bike engines. 

ACDelco 41-993 Professional Iridium Spark Plug – Most Affordable


ACDelco is another spark plug set made of iridium. It is one of the most economical spark plugs on the market presently. It’s also helpful to know that you can purchase eight of these plugs for less than $20.

These spark plugs provide value for your money and help you obtain the maximum power output from the engine. The electrodes are made from iridium and are fine-wired.


The upfront cost of purchasing these plugs is quite low. They can also save you plenty of cash on fuel. The fine wire electrodes facilitate fast fuel ignition, burning the carbon buildup.


AC Delco spark plugs provide an optimal-performing engine with stable idling and smooth acceleration. Since these plugs and their electrodes have high melting points, they can prevent wearing caused by overheating.


  • Cost-effective
  • Have a high melting point
  • Designed for long-lasting engine performance
  • Prevent electrode combustion


  • Not designed for every Harley Davidson motorbike


Generally, you can expect AC Delco spark plugs to improve your Harley Davidson bike. However, you might have to match the plug gap for your Harley version to determine if it’ll fit in there.

E3 Powersports Spark Plug – Best for Sportsters

Design and materials

E3 spark plugs are made with copper as the core material to provide outstanding heat transfer and faster ignition.

Its design comprises a Yttrium-alloy that decreases side wire temperature by about 8% compared to traditional wires. In turn, this helps to reduce pre-ignition and enhance durability.

These spark plugs have colder heat levels to balance with sports-type motorcycles. These plugs cannot damage the Harley engine even on the toughest journeys.


These spark plugs are highly durable and come with faster fitment for your bike. They’re also environmentally friendly, releasing significantly reduced hydrocarbons into the air.


  • Ofer better fuel efficiency
  • Prolong your bike’s engine
  • Provide increased power to your engine
  • Decrease gas emissions


  • Prices are a bit on the higher side


These spark plugs are a universal fit with a Hex size of 5/8 inches and a 12mm thread diameter. Therefore, if your Harley meets these requirements, this is the best product for your bike.

Briggs & Stratton Spark Plug

Design and material

Briggs & Stratton plugs are made of platinum alloy and are designed for OHV engines. Platinum is only second to iridium when it comes to durability. When you install these spark plugs, the best time to replace them is after you’ve traveled 100,000 miles.

They possess high heat tampering abilities and can remain hot for more time to allow oil fouling and carbon to melt away. Therefore, there’s less maintenance and cleaning, and the plugs can last longer.


Briggs has integrated platinum alloys in their plugs to provide high-level engine performance with less fouling and quick engine starting. Also, the spark plugs offer smoother acceleration and improved fuel economy.


  • Reduce the chances of engine misfiring
  • Highly durable
  • Fit OHV engines perfectly
  • Have high heat tampering


  • Costlier compared to other spark plugs


These spark plugs are designed to fit intek OH and vanguard engines. Therefore, before you place an order for them, ensure that they fit your Harley Davidson engine.

What to look for while buying a spark plug for your Harley Davidson?

Spark plugs are designed mainly for motorbikes. They enhance engine performance, starting power, and the motorbike’s fuel economy. The best spark plugs for Harley Davidson keep the engine cool even under tough conditions.

The spark plugs you choose should also maintain or improve the top performance of your Harley. The spark plugs of modern bikes need to be replaced after 15,000 miles depending on the quality of the spark plugs and when they were last replaced.

Frequently Asked Questions

What are the benefits of using a good spark plug for Harley Davidson?

Using the best spark plugs for Harley Davidson offers several benefits such as improved acceleration, more engine output, better engine starts, improved fuel economy, and more.

How often should you change Harley spark plugs?

Depending on your model and the distance you travel, the recommended time to change your Harley spark plugs is between 15,000 and 16,000 miles.

How do you know if your Harley Davidson needs new spark plugs?

When your bike starts to run rough, loses power, or sputters, it’s time to check or replace the existing plugs. It’s important to check them regularly for safety.

How many spark plugs does a Harley have?

A Harley usually has four spark plugs—two on the left side of the bike and two on the right side.

Are iridium spark plugs better for motorcycles?

Yes, they are. Iridium spark plugs are considered six times harder and eight times stronger than platinum.

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What are the best spark plugs for Harley Davidson motorbike? We hope you now have your answer. Our picks are the five best spark plugs for Harley Davidson, and it’s up to you to choose the most suitable option for you. 

Here, it’s important to assess the material of the spark plugs before you choose a particular option. It would help if you also considered the distance you travel and how much you’re ready to part with.

If you want to know which are the best Harley spark plugs among the five of them, every brand is outstanding. All you have to do is use this guide to choose the best one for your bike and enjoy high-performance journeys and adventures.

joshua mattie

Joshua D. Mattie

My motorbike addiction began with 50cc at 5 years old. I rode motocross as a teenager & into my 20's when I worked as a mechanic. This helped me to see the light—sportbikes & cruisers became a passion. Now I'm building BikersRights to be the #1 resource for everything on 2 wheels!

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