Best Spark Plugs For Harley Twin Cam – Perfect Spark Plugs Of 2021

Best Spark Plugs For Harley Twin Cam

Spark plugs are small but extremely important devices that carry electric current from the ignition to the combustion chamber to get the motor running. Without spark plugs, you will not be able to fire up your Harley and be on your way. Every motorcycle requires a good set of plugs that are working well and are made of the highest quality. If your spark plug is not up to the mark and you are looking for a replacement, you have come to the right place. 

In this article, we will speak about the how you can buy spark plugs for your Harley Twin Cam and which ones are the most popular on the market today. Let’s begin.

Choosing Spark Plugs For Your Harley Twin Cam – Buying Guide

These are the factors you should consider while purchasing new spark plugs:

  • The model of your bike: Spark plugs are not made on a one-size-fits-all basis. They are made specifically for certain models. If you pick up two plugs made for different models, you will see a clear difference between the size, diameter, shape, and insulator projection. Only when you choose the right one will it fit your motorcycle accurately.
  • The gap between the electrodes: Spark plugs are supposed to have a certain amount of gap between their electrodes. Some of them come pre-gapped based on the model number while others need to be gapped manually. Regardless, make sure the gap corresponds to the OE specifications.
  • The engine displacement: Engine displacement is the amount of space you have when the piston system is lowered during operation. This is also an important consideration while buying spark plugs.

Other factors include fuel system, the brand of the spark plugs, the price, and the ease of installation.

Best Spark Plugs For Harley Twin Cam

Now, we shall take a look at some of the best spark plugs you can buy for your Harley Twin Cam.

1. NGK Iridium IX Spark Plug For Harley Twin Cam

NGK Iridium IX Spark PlugsNGK is a very popular name when it comes to spark plugs because it delivers exactly what users are looking for – longevity and reliability. These plugs are an example of the same. Below are a few details:

  • They have a nickel core material and iridium electrodes, making them strong spark plugs that can last very long.
  • Once you install this set of spark plugs, you will see an immediate change in the performance of your vehicle. The engine will fire right up and exceed OE standards.
  • You will also see an improvement in the mileage once you install these plugs.
  • Your ride will be smooth and carefree. No more misfires!
  • They are quite easy to install because they have been made keeping OE specs in mind.
  • Improve performance
  • Highly durable and long-lasting
  • Exceed OE standards
  • Affordable
  • Not pre-gapped

Who can use this

buy @ amazon

2. Orange Cycle Parts – Iridium Performance Spark Plugs

Orange Cycle Parts - Iridium Performance Spark PlugsThis set of spark plugs from Orange Cycle Parts has iridium core material and a number of features that make it one of the best sets available today. Below is a closer look:

  • Its iridium electrode is smaller in size when compared to the other spark plugs. This directly means that it needs less voltage to elicit a spark.
  • It provides a hotter spark than OE plugs and has a longer service life as well.
  • The spark plugs are distinctive black ceramic with gold coating, which makes them resistant to corrosion.
  • The thread diameter is 12mm while the thread reach is 11/16 inches.
  • This is a projecting insulator type spark plug with a removable terminal nut.
  • Long-lasting and durable
  • Quick starts and fewer misfires
  • Better performance
  • You won’t get the deep throttle idle that Harley owners love

Who can use this

  • These spark plugs are for 2000 to 2017 Harley Softail Slim Twin Cam

buy @ amazon

3. NGK Iridium Spark Plugs For Harley Twin Cam

NGK Iridium Spark Plugs – 6046This is another set of excellent spark plugs from NGK. They are a set of 4 and will solve all your spark-related problems in one go. Let’s find out why they are so popular:

  • They have an iridium electrode and tend to last much longer than standard plugs.
  • They come pre-gapped for Harley Twin Cam models.
  • The spark plugs are easy to install and provide more horsepower than OE plugs.
  • Many users have also seen an improvement in performance and mileage.
  • The spark they provide is quick and hot, enabling much faster starts.
  • Work as expected
  • Highly efficient spark
  • Exceed OE performance
  • Expensive

Who can use this

  • These have been designed for Harley Davidson Twin Cam and XL

buy @ amazon

4. Accel Spark Plugs For Harley Twin Cam

Accel Spark Plugs – 2418The Accel Spark Plugs are a set of 2 and are quite affordable. If you are looking for good but not very pricey spark plugs, we surely recommend these. Below are a few more details.

  • These spark plugs have been engineered to provide a bigger spark so that the vehicle has more power at high RPM.
  • They work to improve fuel economy and throttle response.
  • With these spark plugs, you won’t have to worry about fouling. 
  • Combustion is also much better with these plugs.
  • They fit as expected and installation doesn’t take a long time.
  • Affordable
  • Good quality
  • Easy to install
  • Not as durable as others

Who can use this

  • These spark plugs are for Harley Davidson Twin Cam 1450/1550 cc models manufactured from 1999 to date.

buy @ amazon

5. Harley Road King Performance Spark Plugs

Harley Road King Performance Spark PlugsThose who are looking for quality spark plugs that don’t burn a hole in their pocket can check the Harley Road King Performance Spark Plugs. They are cheap and good at the same time. Read on for additional details:

  • These are conventional spark plugs designed keeping OE specs in mind.
  • The heat range also corresponds standard spark plugs.
  • The plugs have a black ceramic body, which is quite durable.
  • The insulator is highly resistant to heat shocks thanks to the fact that it is made out of 95% pure alumina. 
  • Insulation is also excellent.
  • Standard spark plugs – they meet OE specs
  • Affordable
  • Not very durable

Who can use this

  • Anyone with a Harley Twin Cam model from 2000 to 2020 can use these spark plugs

buy @ amazon

Why choose iridium spark plugs?

You may have noticed that most of the spark plugs on our list have an iridium electrode. This is because iridium is the best material for spark plugs. It ensures longevity, durability, and high performance. Below are a few more benefits that you should be aware of:

  1. They improve acceleration
  2. They provide more engine power
  3. They improve fuel economy
  4. Starts are faster and misfires are not a headache anymore
  5. They are among the most durable spark plugs

People also ask

Here are the answers to a few commonly asked questions on this topic.

1) How often should you change spark plugs on a Harley Davidson?

You should change spark plugs once in 15,000 miles.

2) Do iridium spark plugs increase horsepower?

Yes, they increase horsepower.

3) Which is better – copper or iridium?

Iridium spark plugs are more long lasting.

4) How long do NGK spark plugs last?

NGK spark plugs can last around 50,000 miles.

5) How often should you change NGK spark plugs?

50,000 miles.

6) Can spark plugs last 200,000 miles?

Well-maintained spark plugs last 100,000 miles. They don’t usually last beyond that.


We hope this article has helped you understand which popular spark plugs you can purchase. The buying guide will also help you compare and choose other plugs. Make sure you check all the mentioned parameters before taking a decision.

Francis Ceron

About Francis Ceron

Did you know the major cause of car failures are due to spark plugs. At sparklplugs guru you wil find all the necessary reviews, guides and facts to improve the performance of your vehicle and have a smooth functioning.

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