Best Spark Plug Wires For Harley Davidson
I remember it like it was yesterday. I was cruisin' down a back road, the kind where the asphalt is more suggestions than reality and the air smells like pine needles and damp earth. My ol' shovelhead was hummin' along, a sweet, deep rumble that always makes me feel like a kid again. Then, out of nowhere, it started to sputter. Not a dramatic, "I'm-about-to-die" sputter, but a little tickle in its throat, a hesitant cough that made me instinctively twist the throttle a bit harder. It wasn't enough. The cough turned into a definite misfire, and suddenly that sweet rumble was replaced by a discordant, uneven beat. The kind of beat that makes you glance at your gauges with a bit of dread. Ugh. Not now. We were miles from anywhere, and the sun was starting to dip below the horizon. My first thought? Spark plug wires. Yeah, those unassuming black cables that are so often overlooked.
And that, my friends, is the often-unwelcome introduction to the world of spark plug wires on your Harley. They're like the unsung heroes, or sometimes, the silent saboteurs, of your engine's performance. You probably don't think about them much, do you? Until, of course, they decide to throw a wrench in your perfectly planned Sunday ride. And then suddenly, you're Googling "Harley spark plug wires" at 7 PM, with a dying battery and a rapidly disappearing sense of adventure.
So, What's the Big Deal with Harley Spark Plug Wires Anyway?
Let's break it down. Your Harley's engine, bless its V-twin heart, relies on a precise little spark to ignite the fuel in each cylinder. This spark is generated by the spark plug, but the power has to get there first. That's where the spark plug wires come in. They're essentially high-voltage pathways, carrying that electrical charge from the ignition coil to the spark plug.
Now, you might think, "They're just wires, right? How much of a difference can they make?" Ah, grasshopper. This is where the magic, and sometimes the madness, of motorcycle tuning truly begins. The quality and type of spark plug wires you choose can have a surprisingly significant impact on your Harley's performance, reliability, and even its fuel efficiency.
Think of it this way: if your ignition coil is a powerful water pump, and your spark plug is the sprinkler head, then your spark plug wires are the hoses. If those hoses are old, cracked, or somehow restricting the flow, you're not going to get the optimal spray pattern, are you? You'll get a dribble, a weak spurt, or worse, nothing at all. Your engine feels that. It feels every bit of that lost energy.
Why Upgrading Your Spark Plug Wires Might Be a Good Idea (Even if Yours Aren't Broken)
Okay, so maybe your current wires aren't actively causing you to break down on a deserted backroad. Lucky you! But even if they're "working," they might not be working optimally. This is where the concept of upgrading comes into play. It's not just about replacing something that's failed; it's about enhancing what's already there.
The stock wires on many Harleys are perfectly adequate for day-to-day riding. They do their job. But they're often made with materials that are designed for longevity and cost-effectiveness, not necessarily for maximum performance. This can lead to a few subtle (and not-so-subtle) issues:
- Resistance: All wires have some degree of electrical resistance. Higher resistance means less of that precious spark energy actually makes it to the plug. Over time, this resistance can increase as the wires degrade.
- Energy Loss: This resistance leads to a weaker spark. A weaker spark means a less efficient combustion process. This can translate to less power, rougher idling, and even increased emissions.
- Radio Frequency Interference (RFI): Cheaper wires can sometimes radiate RFI, which can mess with your electronic devices. Ever had your radio go haywire when your engine's running? Bingo.
- Durability: Harley engines vibrate. A lot. Stock wires, especially over many years and miles, can become brittle, cracked, or prone to chafing, leading to premature failure.
So, even if your current wires are technically functional, an upgrade can offer benefits like a stronger, more consistent spark, leading to better throttle response, a smoother idle, and potentially even a slight bump in fuel economy. And let's be honest, anything that makes your Harley run a little bit sweeter is worth exploring, right?
What Makes "Good" Spark Plug Wires for Your Harley?
Alright, let's get down to brass tacks. When you're looking for the best spark plug wires for your Harley, what are the key features you should be looking for? It's not as simple as just grabbing the shiny ones.
Material Matters: The Core of the Matter
The most significant difference between various spark plug wires lies in their core material. This is where that resistance we talked about comes into play. You'll generally find wires categorized by their resistance:
- Carbon Core/Suppressor Wires: These are what most stock bikes come with. They have a carbon-impregnated core and are designed to suppress RFI. They're good for general use but have higher resistance, meaning a weaker spark.
- Resistor Wires: Similar to carbon core, but the resistor element is usually more distinct. Still higher resistance.
- Suppression Core Wires: These are designed to suppress RFI but typically have lower resistance than standard carbon core wires. This is a step up.
- Solid Core Wires: Back in the day, these were common. They offer very low resistance and a strong spark. However, they are TERRIBLE for RFI and can actually damage your ignition system over time if not used with appropriate suppression. Generally not recommended for modern Harleys.
- High-Performance Wires (Often Silicone or Kevlar/Fiberglass Core): This is where you'll find the real magic for most Harley riders. These wires are designed with very low resistance while also incorporating effective RFI suppression. They often use materials like silicone for the insulation and a core made from conductive materials like fiberglass or Kevlar, often with a conductive inner layer.
For most Harley owners looking for a performance upgrade, you'll want to focus on wires with low resistance and effective RFI suppression. This is the sweet spot that delivers a strong spark without causing electrical gremlins.
Insulation: Keeping the Juice Where It Belongs
The outer insulation of the spark plug wire is just as important as the core. It needs to be able to withstand the heat and vibration of your Harley's engine bay. You'll typically see:
- Silicone: This is the most common and arguably the best material for insulation. It's incredibly resistant to heat, cold, oil, and abrasion. It remains flexible even in extreme temperatures, which is crucial for easy installation and long-term durability.
- Rubber: Older or cheaper wires might use rubber. It's less heat-resistant and can become brittle over time, making it more prone to cracking and failure.
- Teflon/Kapton: Sometimes used as an inner layer or for specific high-temperature applications. Very durable but can be less flexible.
So, look for wires with high-quality silicone insulation. It's a sign of a well-made product that's built to last.
Construction and Quality: The Little Things Add Up
Beyond the core and insulation, the overall construction matters. Pay attention to:
- Ferrules/Boots: These are the ends that connect to the spark plug and the coil. They should be snug-fitting, made of good quality silicone or rubber, and designed to create a tight seal to prevent moisture and dirt ingress.
- Manufacturing Standards: Reputable brands will adhere to strict manufacturing standards to ensure consistency and reliability.
It sounds simple, but a poorly fitting boot can cause arcing or moisture issues. You want those connections to be as secure and weather-resistant as possible.
The Top Contenders: What Are the "Best" Spark Plug Wires for Harleys?
Now, for the million-dollar question (or at least the $50-a-set question): which brands are consistently churning out the good stuff for our beloved Harleys? This isn't an exhaustive list, and frankly, new players emerge, but these are the brands that have earned a solid reputation for quality and performance.
Screamin' Eagle (Harley-Davidson's Own Performance Line)
Let's start with the obvious. Harley-Davidson themselves offer their own performance parts under the Screamin' Eagle banner. Their spark plug wires are usually a good step up from stock, offering improved materials and often a slightly lower resistance. They're designed to work seamlessly with your Harley's existing ignition system and are a safe bet for many riders.
Pros: Genuine Harley-Davidson part, excellent fitment, good quality materials, often readily available at dealerships.
Cons: Can be a bit pricier than aftermarket options, might not offer the absolute lowest resistance or most extreme performance gains compared to specialized aftermarket brands.
Mallory Ignition
Mallory has been in the ignition game for a long time, and they know their stuff. They produce a range of high-performance spark plug wires that are known for their durability and consistent spark. You'll often find their wires feature high-quality silicone insulation and robust internal construction.
Pros: Excellent reputation for reliability and performance, robust construction, often a good balance of price and quality.
Cons: Might require a bit more research to find the exact part number for your specific Harley model.
Accell Performance Wires
Accell is another big name in the performance ignition world. They're known for their focus on reducing resistance and maximizing spark energy. Their wires often feature a multi-core construction with excellent RFI suppression. They're a popular choice for riders looking for that extra bit of performance and responsiveness.
Pros: Focus on low resistance and high energy transfer, excellent RFI suppression, good durability.
Cons: Can be on the higher end of the price spectrum, sometimes the installation might be a little tighter due to thicker wire construction.
MagnaFlow (Yes, the Exhaust Company!)
While MagnaFlow is most famous for its exhaust systems, they also produce a line of high-performance spark plug wires that have gained popularity. They leverage their understanding of engine performance to create wires that are designed for optimal combustion. Their wires often feature silicone insulation and a conductive core designed for minimal resistance.
Pros: Reputable performance brand, good quality materials, often competitively priced.
Cons: Perhaps not as widely recognized for their ignition components as some of the dedicated ignition brands.
Taylor Cable / Pro Wire
Taylor Cable is another long-standing player in the performance automotive and motorcycle aftermarket. Their "Pro Wire" line offers excellent quality with a focus on durability and performance. You'll often find these wires with multi-layer insulation and a low-resistance core, designed to withstand the rigors of Harley riding.
Pros: Strong reputation for durability and performance, good range of options, often available for a wide variety of Harley models.
Cons: Can sometimes be a bit pricier, but you're paying for quality.
Things to Consider Before You Buy
Before you dive headfirst into buying the flashiest set of wires you can find, there are a few more things to ponder. Because, you know, we like to do things right the first time. Mostly.
Your Harley's Year and Model
This is non-negotiable. Spark plug wire lengths and boot types can vary significantly between Harley-Davidson models and even between different years of the same model. Always double-check that the wires you're looking at are specifically designed for your year and model. Getting this wrong means you'll either have wires that are too short, too long, or won't fit properly.
Your Riding Style and Modifications
Are you a casual cruiser who enjoys leisurely rides? Or are you a performance enthusiast who likes to wring every last ounce of power out of your engine? If you've already done some engine modifications (like a performance exhaust or intake), upgrading your spark plug wires can further complement those changes.
For serious performance builds, you might lean towards wires with the absolute lowest resistance. For more general riding, a good balance of low resistance and durability is key. Don't overbuy for your needs, but don't under-spec either.
Budget
Spark plug wires can range from around $30 to over $100. While it's tempting to go for the cheapest option, remember that you often get what you pay for. Investing a little more in a quality set can save you headaches and potential premature failures down the road. Think of it as an investment in your bike's well-being.
Installation: Can You DIY This?
Good news! Replacing spark plug wires on most Harleys is a relatively straightforward DIY job. You usually just need a basic set of tools (screwdrivers, pliers, maybe a spark plug socket). The key is to be methodical:
- One at a time: Always replace one wire at a time to avoid mixing them up.
- Gently does it: When removing old wires, twist and pull at the boot, not the wire itself.
- Check connections: Ensure the new wires snap securely onto the spark plugs and the ignition coils.
- Routing: Make sure the new wires are routed away from hot engine components and moving parts.
If you're not comfortable with basic mechanical tasks, a Harley dealership or a reputable independent shop can easily install them for you. It's a quick job for them.
The Verdict: Is It Worth It?
So, after all this talk about resistance, insulation, and RFI, are upgrading your Harley's spark plug wires really worth the effort and expense? My answer, based on experience and countless hours spent tinkering and riding, is a resounding yes, for most riders.
If your current wires are old, cracked, or showing signs of wear, replacing them is a no-brainer. You'll immediately feel the difference in how smoothly your engine runs. If your wires are "okay" but you're looking to squeeze a little more performance or reliability out of your ride, a quality set of aftermarket wires is a fantastic and relatively inexpensive upgrade. They're one of those "bang for your buck" modifications that can make a noticeable difference in how your Harley performs and feels.
That little misfire I experienced on that backroad? It turned out one of my stock wires had developed a hairline crack. After replacing them with a good set of silicone-jacketed, low-resistance wires, the difference was night and day. The engine idled smoother, acceleration felt crisper, and that sweet, deep rumble was back, even more potent than before. It's the kind of small upgrade that reminds you why you love your Harley so much in the first place. Happy riding, folks!