Owning a Harley Davidson is the dream of every bike enthusiast. And if you’re in for the performance as much as for the looks, then you’re probably aware of the importance of a durable spark plug.
In the early years, spark plugs used to wear out frequently. So it was a bit of a hassle to replace them now and then. The situation has improved over the years though. Newer and much-improved spark plugs are available on the market these days.
But still, it would be a smart idea to equip your Harley Davidson with the best compatible plug available to ensure longevity and keep servicing at bay.
What is a spark plug and how does it work?
To make it simple, it brings your engine to life. Harley Davidson, like plenty of other vehicles, uses a spark-ignition type engine. Electric current travels through the plug from the ignition system to the combustion chamber.
The plug has a metal shell and a metal core electrode, both isolated by porcelain. As high-pressure current passes through the core, it ionizes the surrounding gas, creating a spark. This spark ignites compressed fuel in the combustion chamber. And boom, your engine’s alive!
Things to know beforehand
The working principles of spark plugs are pretty much the same. However, based on the type of the plug, plug gape, core electrode, ground electrode, insulation, shell, brand, etc, performance and durability may vary significantly. So in this guide, we may be able to help you fish out the best spark plugs for Harley Davidson.
#1 Spark Plugs For Harley
One of the best among Harley spark plugs right now. Manufactured by NGK, this Iridium core spark plug is simply amazing. It has a smaller diameter that needs less space than the conventional ones. The iridium core is as much as 25% smaller than even a platinum core, which requires less activation voltage. And less activation voltage means longer life for your ignition system.
This already pre-gapped spark plug features metal shell plating that wards off corrosion even further. Sharp, well-defined tips with high melting points keep it workable for a very long time.
- Brand: NGK
- Model: NGK Iridium IX DCPR7EIX
- Weight: 1.44 ounces
- Core electrode: Iridium
- Thread Dia: 18mm
- Thread Reach: 19mm
- Pre-Gap Size: 0.8mm
- Hex Size: 16mm
Fast and Smooth ignition
Gain up to 3HP with ease
Comes pre-gapped, installation ready
Metal shell plating provides advanced anti-corrosion
25% smaller core electrode. Lower voltage requirement
Better foul protection
Not the best choice for modified engines
Gap adjustment may be necessary
It can be a bit pricey
The Best Spark Plugs for Harley Davidson
|NGK IX DCPR7EIX||Iridium||12||19|
|Pair OEM# 6R12||Copper||12||19|
|NGK Iridium IX DCPR7EIX||16mm||0.8mm|
|NGK (4929) DPR8EA-9||16mm||0.8mm|
|NGK (5129) DPR7EA-9||21mm||0.8mm|
|Accel 2418 Spark Plugs||16mm||1mm|
|Power sports Spark Plug||16mm||0.9mm|
|Pair OEM# 6R12||16mm||0.8mm|
The top best product [hide]
Now, we understand you may not always have time to go through a detailed study. You may simply want your spark plug replaced asap. So, without any further ado, check out our list of some of the best Harley Davidson spark plugs.
As mentioned before, it’s the best-rated spark plug for your Harley Davidson. The smaller Iridium core requires less activation voltage. Letting you have an elongated ignition system life. Advanced anti-corrosion shells extend longevity.
Smooth and pop-up free ignition followed by excellent mileage may just be what you’re looking for. It’s possible to gain up to 3HP with ease. Although it’s recommended to consult with an expert first if you’re running a modified engine. The linked package comes as a pair.
While this is a great choice for improving your stock Harley Davidson, this may cause problems on some modified engines. Due to a smaller reach, the spark may not enter enough into the combustion chamber. If you want to enhance the performance further, you may have to go through the alternatives.
A good choice to replace your stock Harley spark plugs. Increases bike performance and HP. Fits well on all twin-cam engines. Doesn’t come pre-gapped like the previous one though. Adjustments required. Features a core resistor. Removable terminal post. Corrugated ribs prevent flashovers. High heat resistance.
Highly affordable if you’re on a tight budget. Comes in a package of 4 pcs. Iridium core electrode with a long insulator. Multiple ground electrodes let you have a backup. Although fuel efficiency may suffer.
These unique black and gold-finished Iridium core Harley spark plugs are designed to increase performance and withstand corrosion. The smaller core needs lower voltage to activate. Relatively low fuel consumption than the conventional spark plugs. Results in lower carbon emission. Carbon residue build-up is also a minimum.
Accel high-performance spark plugs work great on Harley Davidson Twin Cam models from 1999 and up. It generates a really strong spark that gives higher initial rpm. Ground electrode builds fire inch ball for smoother idle combustion. Consistent ignition Increases performance. The adjustment can be a bit tricky sometimes. Larger gap than conventional ones.
This is an Autolite spark plug with Yttrium alloy core inside. Greatly enhances performance even in modified engine Harley Davidsons. If you’re looking for a breakthrough in your vehicle’s performance parameters, this may just be what you’re looking for. Works great under extreme conditions. Three ground electrodes pull out larger sparks for combustion.
Conventional copper core spark plug. Works great on Harley Road King Twin cam 2000-2020 only. Great heat shock resistance, excellent insulation.
Popular brands that produce Harley Spark Plugs
Harley spark plugs vary from model to model, brand to brand. It’s a growing, competitive market out there. The build, quality, material, performance, everything changes with the name of the brand as they all want to leave their innovative signature touch in their products. Some of the companies have been in this business for centuries. Here is a list of some of the top brands that produce Harley spark plugs.
NGK Spark Plugs
One of the leading OEM producers in the world. They have over 80 years of experience in this market and they always put performance and quality above all others. They offer a lot of models to choose from for your Harley Davidson. By installing their merchandise, most have seen an instant improvement in their bike’s ignition and transmission. For more information and compatibility checks, click here.
Autolite Spark Plugs
The Autolite company started in 1911 by selling buggy lamps. By the year 1936, they produced their first spark plug. Since then they have been developing by leaps and bounds. Presently they have a wide variety of automobile products. The spark plugs they produce for Harley Davidson are some of the bests in the market. Click here for more information.
Pulstar Spark Plugs
Pulstar is an innovative brand. They use unconventional plasma-assisted combustion technology that boosts your Harley’s horsepower. Moreover, an improved torque and throttle response have been recorded. Pulstar ensures quicker response, efficient fuel consumption, and reduced carbon emission. Check out more from here.
Denso Spark Plugs
A popular Japanese brand. Denso started as part of the Toyota brand but later emerged as a self-dependent company. They produce quality spark plugs Harley Davidson as well as other essential components for the vehicle industry. Get to know them better at here.
E3 Spark Plugs
The E3 spark plugs feature DiamondFire spark plug technology. They promise increased vehicle performance, efficient fuel consumption, and lower carbon emission. Multiple ground electrodes generate larger bursts of sparks. These plugs are excellent for racing gears as they prioritize better burn for the engine. Their premium performance OEM replacement plugs can certainly fire up your engine like never before. Wanna know more? Just click here.
Spark plugs for different Harley Davidson models
Compatibility is one of the major issues to look out for when replacing your spark plug. Depending on your Harley model, it can be tricky sometimes. There are hundreds of brands out there that make spark plugs for Harley Davidson. They produce model-specific products. So the same plug that works great on a model may not turn out to be the best option for another one.
Some of the leading brands like NGK, Autolite, E3, Pulstar, Denso, Champion, Accel, Brisk, etc produce universally compatible quality plugs. We’ve prepared a list of Harley models and the type of OEM components they work best with to give you a better chance of filtering.
Spark plugs for Harley Davidson 2015 FLHTK
NGK- DCPR7EIX, Autolite-XS4164, Accel U-Groove 2418, Champion-RA8HC, Pulstar Plasma-HE1HT9, Accel Platinum-Y2418P.
Spark plugs for Harley Davidson 1200
NGK- DCPR7EIX, Autolite-XS4164, Accel U-Groove 2418, Pulstar Plasma-HE1HT9, E3.36.
Spark plugs for Harley Davidson Sportster 883
NGK- DCPR7EIX, Harley Davidson Stock OEM-6R12, E3.36, Denso-IXU22, Champion-RA8HC, Bosch-0242135515.
Spark plugs for Harley Davidson Road King
NGK- DCPR7EIX, Autolite-XS4164, E3.36, NGK-DCPR7E, Accel Platinum-Y2410P, Champion – RN12YC, Champion-RA8HC, Pulstar Plasma-HE1HT9.
Spark plugs for Harley Davidson 103
NGK- DCPR7EIX, Brisk-6R12, E3.36, Champion-RA8HC, Brisk-BR14YS-9.
Spark plugs for Harley Davidson Twin Cam
NGK-6046, NGK-DCPR7EIX, Harley Davidson OEM-6R12, E3.36, Denso-IXU22, Champion-RA8HC, Bosch-0242135515.
Spark plugs for Harley Davidson Evo
NGK-BPR5EIX-11, Harley Davidson OEM-5R6A, E3.34, Denso-IW16, Champion-RN12YC, Bosch-0242229779.
As you may have noticed, some of the spark plug versions go well with almost any Harley Davidson model. So even if your Harley is not listed above, there’s a chance that these plugs will work on yours too. Although, it’s always better to double-check. Consult with an expert about your specific model. Highly advised if you have a modified engine.
Why you should change spark plugs you will know from this video:
Spark plugs for Harley Davidson FAQs
What is Gapping?
What does the metal do in a spark plug?
How often should I change the plug?
Longer or shorter reach?
What are “Hot” and “Cold” plugs?
Which thermal range to select?
Since there are plenty of options out there, equipping your Harley Davidson with the best compatible spark plug can be tricky. A well compatible plug can improve your engine power and speed, grant swift transmission, reduce corrosion, and carbon emission. On the other hand, a bad (not compatible) one is bound to give you a bitter experience.
For the best results, choose between a modern Iridium and Yttrium core-based plug considering your model. Keep the thermal range, gap size, etc in mind before finalizing your purchase. For pre-gapped plugs, check the gap range.
Consult with an expert first if you have a modified engine or in any case you’re not certain. Remember, you could always visit Harley Davidson’s official service panel for any further support. Happy Rolling!