Best Motorcycle Spark Plugs: Change Your Spark Plugs Anywhere

Changing your own spark plugs is a great way to save money.

byJonathon Klein|
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BYJonathon Klein/ LAST UPDATED ON March 17, 2023

Maintaining your motorcycle’s spark isn’t just done by giving it a good wash and fresh fluids every so often, it’s also down to keeping its spark plugs carbon-free and sparking away. These minuscule parts are some of the most important items in your engine, and keeping them in tip-top condition is paramount to having a healthy motorcycle. But which spark plug is the best? Which is right for your motorcycle? Well, fellow riders, we’ve put together the following list to help you get on your way. 


However, what I want to impart to you is that spark plug sizes and types may differ from motorcycle to motorcycle, and it’s vitally important that you check your motorcycle’s manual to ensure you purchase the right spark plug for your application. Do your homework, then come back here!

Best Overall
NGK Iridium IX Spark Plugs

NGK Iridium IX Spark Plugs

Summary

These NGK iridium spark plugs come in a pack of two and a gap of .025 out of the box which can be further set and adjusted. Works great on Harley-Davidson motorcycles.

Pros
  • Bodies of these spark plugs are made from iridium, making ignition much faster and effective in comparison to spark plugs with copper bodies
  • Solid iridium core holds gases in place and allows for a more responsive engine
Cons
  • These spark plugs have high reactivity and fuel up too easily for carbureted bikes
Best Value

E3 Spark Plug Powersports

Summary

These E3 spark plugs are widely popular among motorcyclists and are a step up from the standard spark plug. They come in a variety of sizes.

Pros
  • Features a DiamondFIRE ground electrode configuration for faster ignition
  • Nickel-plated to last longer and protect against corrosion
Cons
  • This plug does not work well on motorcycles with large gaps. This spark plug works best with Harley-Davidson motorcycles.
Best OEM Replacement

NGK Spark Plugs - Standard

Summary
NGK returns to the list as, well, the company makes some of the best powersport spark plugs out there. 
Pros
Trusted brand that won’t break the bank. Pre-gapped for ease of installation.

Cons
May not be the right thread for every model, check your motorcycle’s manual. 

Summary List

Our Methodology

We’ve been working on our motorcycles for decades at this point. And we’ve changed our fair share of spark plugs. We used that institutional knowledge and experience and threw it into this buying guide. 

Best Motorcycle Spark Plug Reviews & Recommendations

These NGK Iridium IX Spark Plugs are a set of genuine OEM spark plugs that come pre-gapped and threaded to fit in most Harley-Davidson motorcycles. They have an iridium tip, which means they can achieve fast and effective ignitions with consistent sparks. The iridium conduction tip is laser welded and can last for about 60,000 miles. They are designed to reduce voltage requirements and consequently prolong the life of your ignition system.


The spark plug has a unique long insulator nose to prevent fouling of the plug tip, engine misfires, and natural deterioration. It’s also 25 percent smaller than most platinum electrodes to help deliver up to 3 horsepower. The plugs are metal plated for advanced anti-corrosion and anti-wear properties. In addition, they can withstand extreme heat conditions and are, therefore, suitable for performance enthusiasts.

The E3 Spark Plug Powersports is designed to enhance the performance of your engine by providing a healthy power boost. It features a double DiamondFire ground electrode, which enhances the amount of combustion pressure that results from each power stroke of the engine. This translates to improved fuel economy, enhanced power output, reduced emissions, and faster starts. 


Faster flame ignition by the dual ground electrode results in optimal combustion of the air and fuel mixture. This means that your bike will experience smoother acceleration and idle. It's also designed with colder heat ranges than your original spark plug, so it can handle intense conditions in the engine and allow for performance modification.

The NGK Standard Spark Plugs are a factory part for many bikes, so if you're looking for an OEM replacement plug, this is the way to go. As the name indicates, they are standard plugs with excellent reliability, power, and workmanship. 


These NGK plugs have a deep-seated copper core and work well in a wide temperature range, preventing fouling and pre-ignition. They provide good heat dissipation and electrical insulation due to their high alumina ceramic construction. The nickel alloy tips also promote a longer lifespan. These plugs fit perfectly, are easy to install, and you may not need to gap the plugs because they are already pre-set within the recommended spec.

The Accel U-Groove Spark Plugs For Harley Big Twin / Sportster are specifically designed for 1986-2021 Harley-Davidson motorcycles. Sold as a set, these plugs have a patented U-shape design in the electrode that makes a wide, hot spark that starts standard and high-compression bikes. 


You don't have to worry about flashover or overheating in high-performance bikes and long-range situations because the plugs feature a sintered alumina heavy-duty five-rib insulator. These copper/nickel alloy plugs are foul-resistant and dissipate heat well due to their construction. They also have an electric seat heal to minimize leakage. Users report that these plugs can improve start-up as well as performance.

Honorable Mention

Pulstar Spark Plug

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Enerpulse Technologies, the company behind the Pulstar Spark Plug, promises that these plugs will provide a faster throttle response, smoother idle, better fuel economy, and higher-than-average horsepower and torque. The plugs use plasma-assisted combustion technology to achieve these goals. They have a patented internal capacitor developed with assistance from a U.S. Department of Energy laboratory. 


The high-intensity electrical pulse ionizes the air/fuel mixture and injects it with combustion-enhancing plasma, which in turn ignites fuels, quickly burns it, and maximizes a vehicle's horsepower, torque, and throttle response. Users report experiencing a significant improvement after installing these plugs. Overall, your bike should perform better, start easier, and reach idle RPMs quicker. It's an excellent low-cost improvement because they are reasonably priced.

Our Verdict

I’ll say this again, but the best spark plug for your motorcycle is going to be the one that fits your motorcycle’s engine and fits within your price bracket. That said, if your motorcycle takes NGK’s Iridium spark plugs, then you’ll be super happy. If you want something a little more inexpensive, E3’s powersport spark plugs will do the job.

Buying Guide for Motorcycle Spark Plugs

Here’s everything you need to know to make an informed decision. 

Key Features 

Ground Electrode Type  

A spark plug can have two or more ground electrodes surrounding the central electrode. The ground electrode is the probe-like structure that protrudes from the threads. The most common type is a single and double electrode. More electrodes means that you can extend the life of the spark plug since you can rely on the second ground electrode when one burns out. However, it compromises the fuel efficiency of your vehicle. 

Threads 

The number of threads on the spark plug determines its level of reach into the combustion chamber. If the threads are few, you won’t get good combustion since the spark plug can’t project into the chamber. If there are too many, and the spark plug is longer than usual, it may get damaged by the pistons when the engine is running or the fuel will ignite sooner than expected. To get the right size, choose the one that’s the same size as your motorcycle’s original spark plug. 

Heat Range

This is the speed at which the spark plug can transfer heat from the firing tip to the cooling system. It can be used to tell the amount of time that a spark plug can withstand heat combustion before it gets damaged. The heat range is typically displayed in numerical figures in your owner’s manual. Most motorcycle spark plugs have a heat range of 900 to 1,500 degrees Fahrenheit.

Types of Motorcycle Spark Plugs

Copper 

Copper-tipped spark plugs are the most common and standard form of spark plug. Copper is one of the best conductors of electricity, and are typically inexpensive. 

Single Platinum 

Single platinum plugs are more expensive than copper despite the fact that they are less conductive than the latter. That’s because they tend to last longer since the metal does not erode or wear out as easily as copper.  

Double Platinum 

Double platinum spark plugs have double plates of platinum on the tip. They can, therefore, last longer and perform better than the single-platinum versions. They are also more expensive. 

Iridium 

Iridium has great conductivity and is also highly resistant to corrosion at high temperatures. Like those temperatures you’d find in an internal combustion engine. These are the most expensive spark plugs out there, though.

Motorcycle Spark Plug Pricing

Our advice? The average consumer doesn’t need to spend more than $25 for a set of plugs. 

FAQs

You’ve got questions. The Drive has answers.

Q: How hard is it to gap a spark plug to the correct size?

A: Pretty easy, as there’s a simple tool you can pick up and use for less than $5.

Q: How often should I change my motorcycle’s spark plugs?

A: This varies depending on how often you ride your bike, the distance you cover, and the age of your motorcycle. Regardless of your riding habits, it’s important to inspect your spark plugs on a regular basis.

Q: Does the material of the spark plug matter?

A: Spark plugs ignite sparks, and different metals do so at different levels. Spark plugs can have platinum or copper cores, and even be nickel-plated. 

Why Trust Us

Our reviews are driven by a combination of hands-on testing, expert input, “wisdom of the crowd” assessments from actual buyers, and our own expertise. We always aim to offer genuine, accurate guides to help you find the best picks.

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