When it comes to keeping your Yamaha WaveRunner running at peak performance, choosing the right spark plugs is essential. The best spark plugs for Yamaha WaveRunner ensure reliable ignition, improved fuel efficiency, smoother acceleration, and longer engine life. Whether you’re cruising on a FX140, pushing a GP1800R to its limits, or maintaining a VX Cruiser, upgrading to high-quality iridium or OEM-spec spark plugs can make a noticeable difference in how your watercraft performs on the water. In this expert-reviewed roundup, we’ve tested and compared the top spark plug options to help you make a smart, informed decision—without overpaying or risking engine issues.
Quick Product Comparison
Our Top 5 Best Spark Plugs For Yamaha Waverunner Reviews – Expert Tested & Recommended
1. 6955 Iridium Spark Plugs 4 Pack for Yamaha WaveRunner FX140, Aprilia RSV4, Ducati 999 – Replaces CR9EB
If you’re looking for a direct, high-performance replacement that fits multiple Yamaha WaveRunner models and even some high-end motorcycles, this 6955 Iridium Spark Plug 4-pack is our top pick. Designed to replace the CR9EB and OE number 6955, these plugs deliver consistent ignition and long-term reliability—perfect for weekend riders and frequent water adventurers alike.
Key Features That Stand Out
- ✓ Pre-gapped to 0.8mm (0.032”) for hassle-free installation
- ✓ Made with premium iridium for superior spark efficiency and longevity
- ✓ Direct OEM replacement—meets or exceeds factory standards
- ✓ Compatible with Yamaha FX140, Aprilia RSV4, Ducati 999, and Husqvarna 250/310 series
Why We Recommend It
These spark plugs combine precision engineering with durable materials, ensuring your WaveRunner starts easily and runs smoothly even after long storage periods. The iridium construction resists wear far better than standard copper plugs, meaning fewer replacements and more time on the water.
Best For
Owners of Yamaha FX140 and multi-vehicle enthusiasts who want a reliable, long-lasting plug that works across different engines.
Pros and Cons
Pros:
- Excellent build quality with genuine iridium tips
- Pre-gapped design saves time and reduces installation errors
- Wide compatibility beyond just WaveRunners
- Consistent performance in wet and high-humidity conditions
Cons:
- Slightly higher price point than generic copper plugs
- Limited customer reviews available due to newer listing
Customer Reviews
“Customer Review: Installed these in my FX140 and noticed smoother idle right away. No more hesitation when hitting the throttle—definitely worth the upgrade.”
“Customer Review: Used these as replacements for my Ducati 999 and they’ve been flawless. Great quality for the price.”
2. NGK LFR6A 6668 Spark Plugs 8 Pack for Watercraft FX FZR FZS VX VXR VXS – 26.5mm Reach, 0.9mm Gap
NGK is a trusted name in ignition systems, and this 8-pack of LFR6A 6668 spark plugs offers outstanding value for owners of multiple WaveRunners or those who prefer to keep spares on hand. With a 26.5mm reach and 0.9mm gap, these plugs are engineered specifically for Yamaha’s 1.8L marine engines and deliver reliable performance season after season.
Key Features That Stand Out
- ✓ NGK V-Power design with v-cut center electrode for stronger spark
- ✓ 26.5mm thread reach—perfect fit for FX, FZR, FZS, VX, VXR, and VXS models
- ✓ 0.9mm pre-set gap ensures optimal combustion
- ✓ Resistor type reduces electromagnetic interference
Why We Recommend It
NGK’s V-Power technology gives these plugs an edge over standard designs by directing the spark to the electrode edge, improving flame kernel development. This results in better throttle response and smoother operation—especially noticeable in saltwater environments where corrosion resistance matters.
Best For
Multi-WaveRunner owners, rental fleets, or anyone who wants extra plugs for seasonal maintenance without breaking the bank.
Pros and Cons
Pros:
- Excellent value in an 8-pack—great for spares or multiple units
- Proven NGK reliability and marine-grade construction
- Improved cold starts and reduced misfires
- Widely used and recommended by mechanics
Cons:
- Not iridium—shorter lifespan than premium iridium options
- Gap may need verification on older models
Customer Reviews
“Customer Review: Direct replacement for the marine Yamaha 1.8L. And way better price than the dealership. According to the manual they need to be changed along with the annual oil change.”
“Customer Review: Worked as a good spark plug should. Made my Yamaha boat purr.”
3. NGK 3672 LFR6A-11 Iridium Spark Plugs 4 Pack – High Performance, Durable Ignition for Motorcycles & Watercraft
Don’t let the affordable price fool you—this NGK LFR6A-11 Iridium 4-pack delivers premium performance at a budget-friendly cost. Featuring genuine iridium tips and a 11mm reach, these plugs are ideal for WaveRunners that require a slightly longer reach than standard models, offering enhanced durability and consistent ignition under demanding conditions.
Key Features That Stand Out
- ✓ Genuine NGK iridium construction for extended service life
- ✓ 11mm reach—ideal for specific Yamaha marine applications
- ✓ Trivalent metal plating resists corrosion and seizing
- ✓ Precision-machined electrodes for stable spark delivery
Why We Recommend It
You get NGK’s legendary quality without the premium price tag. These plugs are perfect if you’ve been using standard copper or platinum plugs and want to upgrade to iridium for better longevity and performance—without overspending.
Best For
Budget-conscious riders who still want top-tier materials and don’t want to compromise on reliability.
Pros and Cons
Pros:
- Affordable entry into iridium spark plug technology
- NGK brand assurance—no risk of counterfeit issues
- Noticeable improvement in throttle response over old plugs
- Great for seasonal swaps on lightly used WaveRunners
Cons:
- Only 4 plugs—may need to buy multiple packs for larger fleets
- Reach length may not fit all models (verify before purchase)
Customer Reviews
“Customer Review: Well. I bought these to replace the ones in my Yamaha 350HP F350 5.3L V8 outboard motor. The original ones had a mere 115 hours on them but I was in the maintenance mode so, I decided to change the plugs. The runs as good with the new plugs as it did with the older ones so, not sure it was a major or minor improvement but, I had the satisfaction that the hourly service interval’s been taken care of.”
“Customer Review: Was skeptical buying these online, worried I’d get a knock off of some sort but these are genuine NGK plugs. My jet ski ran noticeably better with a fresh set, would buy another just to have a clean spare set!”
4. LFR6A Iridium Spark Plugs 4 Pack for Yamaha WaveRunner FX, GP1800R, VX Cruiser 2020-2022 – Replaces 6668
Designed specifically for newer Yamaha WaveRunner models from 2020–2022, this LFR6A Iridium 4-pack offers OE-standard performance at a fraction of the dealer cost. Built with a copper-core center electrode and iridium tip, these plugs ensure reliable starts, smooth acceleration, and reduced emissions—perfect for modern high-output engines.
Key Features That Stand Out
- ✓ Direct replacement for OE number 6668
- ✓ Compatible with FX, GP1800R, and VX Cruiser (2020–2022)
- ✓ Iridium construction with isostatic ceramic insulator
- ✓ Meets or exceeds OEM specifications for fit and function
Why We Recommend It
These plugs give you OEM-level performance without the markup. If you own a newer WaveRunner and want peace of mind knowing you’re using a plug designed for your exact model, this is a smart, cost-effective choice.
Best For
Owners of 2020–2022 Yamaha FX, GP1800R, or VX Cruiser models looking for affordable OEM replacements.
Pros and Cons
Pros:
- Exact fit for recent WaveRunner models
- High-quality iridium tip improves spark efficiency
- Much cheaper than buying from a Yamaha dealer
- Good corrosion resistance for saltwater use
Cons:
- Limited compatibility with older models
- Brand is less established than NGK (though quality appears solid)
Customer Reviews
“Customer Review: Was a little concerned not buying NGK plugs, but we don’t use our jet skis that much during the year and these worked great and with its low cost I can afford to have new plugs for all 4 of my skis every season! Great choice!”
“Customer Review: Was a little concerned not buying NGK plugs, but we don’t use our jet skis that much during the year and these worked great and with its low cost I can afford to have new plugs for all 4 of my skis every season! Great choice! Read more”
5. NGK LFR6A 6668 Spark Plugs 4 Pack for Watercraft FX FZR FZS VX VXR VXS – 26.5mm Reach, 5K Ohm
This 4-pack of NGK LFR6A 6668 spark plugs offers the same trusted performance as the 8-pack but in a smaller quantity—ideal for single-WaveRunner owners or those doing routine maintenance. With a 26.5mm reach and 5K ohm resistor, these plugs reduce electrical noise while delivering reliable ignition across a range of Yamaha watercraft.
Key Features That Stand Out
- ✓ NGK V-Power design enhances spark development
- ✓ 26.5mm thread reach matches OEM specifications
- ✓ 5K ohm resistor minimizes radio frequency interference
- ✓ Compatible with FX, FZR, FZS, VX, VXR, and VXS models
Why We Recommend It
Sometimes less is more. If you only need one set per season, this 4-pack gives you NGK quality without excess inventory. It’s a no-brainer for owners who prioritize brand reliability and proper fit.
Best For
Single WaveRunner owners doing annual maintenance or replacing worn plugs on a well-used ski.
Pros and Cons
Pros:
- Authentic NGK product with full warranty support
- Perfect fit and function for listed Yamaha models
- Improved cold starts and idle stability
- Resistor design protects onboard electronics
Cons:
- Higher per-unit cost than bulk packs
- Not iridium—requires more frequent replacement than premium options
Customer Reviews
“Customer Review: Fit a 2023 Yamaha AR190 just fine. OEM spark plugs.”
“Customer Review: Perfect replacement for OEM Yamaha. My plugs were long past due for a change. We noticed a major improvement in performance.”
Complete Buying Guide for Best Spark Plugs for Yamaha Waverunner
Essential Factors We Consider
When selecting the best spark plugs for your Yamaha WaveRunner, we focus on four key factors: compatibility, material quality, gap specification, and brand reputation. Always verify that the plug matches your model’s required reach, thread size, and heat range. Iridium plugs last longer and perform better than copper or platinum, but cost more. Pre-gapped plugs save time and prevent misfires. And sticking with trusted brands like NGK ensures you’re not risking counterfeit parts that could damage your engine.
Budget Planning
Spark plug prices range from under $20 for basic 4-packs to over $50 for premium iridium sets. If you ride frequently or in harsh conditions (like saltwater), investing in iridium is worth it—they can last 2–3 times longer than standard plugs. For occasional riders, a quality NGK copper or platinum plug offers great value. Consider buying multi-packs if you own more than one WaveRunner or want spares for emergencies.
Final Thoughts
Upgrading your spark plugs isn’t just about fixing a problem—it’s about preventing one. Fresh plugs improve fuel economy, reduce emissions, and keep your WaveRunner running like new. Whether you choose our Best Choice iridium option or the budget-friendly NGK packs, regular replacement every 100–200 hours (or annually) is a small step that pays big dividends in performance and reliability.
Frequently Asked Questions
Q: How often should I replace spark plugs on my Yamaha WaveRunner?
A: Most manufacturers recommend replacing spark plugs every 100–200 operating hours or once per season—whichever comes first. If you notice hard starting, rough idle, or reduced acceleration, it’s time for a change regardless of hours.
Q: Can I use automotive spark plugs in my WaveRunner?
A: No. Marine engines operate under higher stress and moisture exposure. Always use spark plugs specifically rated for marine or watercraft use to avoid corrosion, misfires, or engine damage.
Q: What’s the difference between iridium and copper spark plugs?
A: Iridium plugs have a harder, more durable electrode that lasts significantly longer (up to 40,000 miles vs. 20,000 for copper) and provides a stronger, more consistent spark. Copper is cheaper but wears faster.
Q: Do I need to gap these spark plugs before installation?
A: Most modern plugs, especially those labeled “pre-gapped,” come ready to install. However, always double-check the gap with a feeler gauge to ensure it matches your engine’s specs (usually 0.8–0.9mm for WaveRunners).
Q: Will new spark plugs improve my WaveRunner’s top speed?
A: Not dramatically—but they can restore lost performance due to worn plugs. You’ll likely notice smoother acceleration, better throttle response, and easier starts, which enhances the overall riding experience.
Ready to give your Yamaha WaveRunner the ignition upgrade it deserves? Click any “Check Price” button above to grab your preferred spark plugs today—and get back to enjoying the water with confidence!
Sagor Jahan is the founder and author of Automopromo.com, dedicated to delivering insightful tips, reviews, and updates in the automotive and promotional industry. With a passion for innovation and clear guidance, Sagor helps readers make informed decisions and stay ahead in the ever-evolving automotive world.
