Spark Plugs

Harley Spark Plugs — Reliable Ignition for Your Harley Engine

Essential Spark Plugs for Your Harley Motorcycle

Welcome to Get Lowered — your go-to source for premium Harley parts and accessories. Our Harley spark plugs selection offers a wide range of high-quality spark plugs designed to deliver dependable ignition, strong combustion, and consistent engine performance. Whether you’re replacing worn plugs on your daily ride, restoring a classic, or upgrading for a custom or performance-tuned build — we provide spark plugs built for reliability, smooth starts, and clean combustion.

Why Spark Plugs Are Critical for Your Harley

A spark plug is one of the most important parts in a motorcycle’s ignition system. It generates the spark that ignites the air-fuel mixture in the engine’s combustion chamber — without a properly functioning spark plug, your engine can’t start or run properly.

With fresh, correctly-spec spark plugs you get:

• Consistent ignition & reliable starts — Clean, functional spark plugs ensure your engine starts quickly and reliably with minimal cranking, even after long periods of inactivity.

• Efficient combustion & smooth running — Proper spark ensures complete burning of fuel, which leads to smoother idle, responsive throttle, better power delivery, and better fuel economy.

• Reduced misfires, rough-idle, and poor performance — Worn, fouled, or incorrect spark plugs can cause misfires, hesitation, poor throttle response, and inconsistent performance.

• Better fuel efficiency and lower emissions — Clean and correctly gapped spark plugs improve combustion efficiency — which helps reduce wasted fuel and decreases exhaust emissions.

What You’ll Find in Our Spark Plugs Collection

In our “Harley Spark Plugs” category, you’ll find a variety of options to suit different bikes, riding styles, and engine setups:

• OEM-style replacement spark plugs — for stock restorations or standard maintenance

• Premium spark plugs (iridium, platinum, or high-grade alloys) — for longer service life, improved ignition energy, and better engine performance under demanding conditions. 

• Plug sets matched to popular Harley model lines and engine types — ensuring correct thread size, heat range, and electrode configuration

• High-performance plugs optimized for aftermarket builds, modified engines, or performance upgrades (higher compression, exhaust mods, etc.)

• Full plug sets (per cylinder or per engine) ready for installation — ideal for tune-ups, rebuilds, or seasonal maintenance

When to Replace or Upgrade Your Spark Plugs

You should consider replacing or upgrading your spark plugs if you notice any of the following:

• Difficulty starting the engine, especially after sitting or in cold conditions

• Rough idle, misfires, hesitation during throttle, or inconsistent power delivery

• Decreased fuel efficiency, poor throttle response, or noticeable drop in power

• High-mileage plugs or plugs that haven’t been replaced for many seasons — spark plugs degrade over time and lose effectiveness.

• You’re upgrading other engine components (exhaust, intake, compression, etc.) or using aftermarket tuning — a better spark plug can help handle increased ignition demands

Ready to Ignite Your Engine Right? Browse Our Harley Spark Plug Selection Now

Don’t settle for weak ignition or spotty performance — equip your Harley with quality spark plugs that deliver clean combustion, reliable starting, and smooth running. Explore our full spark plug lineup and find the right fit for your ride today.