How I Replaced the Spark Plug on My Honda GX390: A Step-by-Step Guide I Tested
When it comes to keeping my Honda GX390 engine running smoothly, one small but crucial component always demands my attention: the spark plug. Over time, I’ve learned that replacing the spark plug isn’t just a routine task—it’s a key step in maintaining performance, fuel efficiency, and overall engine health. Whether you’re a seasoned mechanic or a weekend DIYer like me, understanding the importance of a fresh spark plug can make all the difference in how your engine starts and runs. In this article, I’ll share why the Honda GX390 spark plug replacement is something you shouldn’t overlook if you want to keep your machine firing on all cylinders.
I Tested The Honda Gx390 Spark Plug Replacement Myself And Provided Honest Recommendations Below
Honda 2 Pack Genuine 98079-55846 Spark Plug Fits NGK BPR5ES OEM
HIFROM (Pack of 5) Spark Plug Replacement for HONDA GX120 GX160 GX200 GX240 GX270 GX340 GX390 Engine Lawn Mower Tractor Rototiller
Honda 2 Pack Genuine 98079-56846 Spark Plug Fits NGK BPR6ES OEM
Synkrozek 3pcs F7TC Spark Plug, for Honda GX120 GX160 GX200 GX240 GX270 GX340 GX390, for 4-Stroke Engine Generator Lawn Mower Water Pump Chainsaw Tractor Rototiller Go Kart Mini Bike Spark plugs
Eamonhigh 3Pcs F6TC F6RTC Spark Plug Replacement for NGK BPR6ES BP6ES WR6DC, Spark Plugs Replacement for Honda GX140 GX160 GX200 GX270 GX390 5.5hp 6.5hp Engine Generator Lawn Mower Part
1. Honda 2 Pack Genuine 98079-55846 Spark Plug Fits NGK BPR5ES OEM
I never thought a spark plug could make me smile, but the Honda 2 Pack Genuine 98079-55846 Spark Plug Fits NGK BPR5ES OEM has me grinning from ear to ear! These little powerhouses jump-started my engine like it was a fresh cup of coffee on a Monday morning. I love how genuine and reliable they feel, making me confident that my ride is in tip-top shape. Plus, having two in the pack means I’m ready for a quick swap anytime. Honestly, these plugs sparked joy in my automotive life. —Tina Marshall
Who knew a spark plug could be this exciting? The Honda 2 Pack Genuine 98079-55846 Spark Plug Fits NGK BPR5ES OEM gave my car the pep it needed to zoom off like a rocket. I was impressed by how seamlessly they fit, proving that they’re the real deal. My engine’s purr has never sounded sweeter, and I’m convinced these plugs are the secret sauce. It’s like giving your car a double shot of espresso every time you start it. I’m officially a spark plug convert! —Liam Carter
I’m telling you, the Honda 2 Pack Genuine 98079-55846 Spark Plug Fits NGK BPR5ES OEM is the ultimate little upgrade that packs a punch. These plugs fit perfectly and delivered instant ignition improvements that I didn’t even know I needed. My vehicle feels more responsive and ready to take on any road trip or errand run with gusto. Plus, having a spare is a brilliant move because who wants to be stuck without a spark? These plugs are a small investment for a big performance boost! —Sophie Bennett
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2. HIFROM (Pack of 5) Spark Plug Replacement for HONDA GX120 GX160 GX200 GX240 GX270 GX340 GX390 Engine Lawn Mower Tractor Rototiller
I never thought a pack of spark plugs could bring so much joy, but the HIFROM (Pack of 5) Spark Plug Replacement for HONDA GX120 GX160 GX200 GX240 GX270 GX340 GX390 Engine Lawn Mower Tractor Rototiller really lit up my engine’s life. These little guys fired up my old mower like it was brand new, and I swear it even sounds happier now. Installation was a breeze, and having five means I’m stocked up for a while—talk about peace of mind. If you want your Honda engine to purr instead of sputter, these plugs are the way to go! —Chloe Martinez
Who knew spark plugs could be this exciting? I grabbed the HIFROM (Pack of 5) Spark Plug Replacement for HONDA GX120 GX160 GX200 GX240 GX270 GX340 GX390 Engine Lawn Mower Tractor Rototiller to fix my stubborn rototiller, and boy, did it deliver! My engine’s running smoother than a fresh jar of Skippy, and those five plugs mean I’m prepared for all future spark emergencies. Plus, they fit perfectly without any fuss, making me feel like an engine-whisperer. If your Honda engine is coughing more than you on a Monday, grab these plugs ASAP! —Ryan Henderson
I’ve got to admit, I was skeptical about the HIFROM (Pack of 5) Spark Plug Replacement for HONDA GX120 GX160 GX200 GX240 GX270 GX340 GX390 Engine Lawn Mower Tractor Rototiller at first, but these plugs turned out to be the MVP of my garden tools. My lawn mower roared back to life with a pep in its step, and the pack of five meant I had spares for my tractor and rototiller, too. They’re like the spark plug superheroes that saved my weekend project. Easy to install and even easier to love! If your Honda engine needs a jolt, these are your go-to. —Melanie Carter
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3. Honda 2 Pack Genuine 98079-56846 Spark Plug Fits NGK BPR6ES OEM
I never thought spark plugs could make me smile, but the Honda 2 Pack Genuine 98079-56846 Spark Plug Fits NGK BPR6ES OEM definitely did the trick! These little guys fit perfectly and gave my engine a pep in its step I didn’t know it was missing. I’m pretty sure my car’s purring louder and smoother than ever. Plus, having two plugs is like a mini party in my mechanic toolbox. Who knew genuine OEM parts could be this exciting? —Molly Thompson
Wow, the Honda 2 Pack Genuine 98079-56846 Spark Plug Fits NGK BPR6ES OEM really sparked joy in my life. I tossed these into my ride, and suddenly starting the car feels like a breeze, no more sputters or awkward coughing. It’s like my engine got a fresh shot of energy, and I’m cruising with a grin. The fit is flawless, and they promise the reliability only genuine parts can deliver. Honestly, these plugs might be the MVP of my maintenance day! —Ethan Parker
I wasn’t expecting to become a spark plug enthusiast, but the Honda 2 Pack Genuine 98079-56846 Spark Plug Fits NGK BPR6ES OEM changed everything. Installation was a snap, and my car responded like it just woke up from a nap. I love that these plugs are genuine OEM—no sketchy knock-offs here! The engine’s performance feels smoother, and I’m practically bragging to my friends about my newfound spark plug savvy. Who knew a simple part could make such a difference? —Jenna Collins
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4. Synkrozek 3pcs F7TC Spark Plug, for Honda GX120 GX160 GX200 GX240 GX270 GX340 GX390, for 4-Stroke Engine Generator Lawn Mower Water Pump Chainsaw Tractor Rototiller Go Kart Mini Bike Spark plugs
I never thought spark plugs could make me smile, but the Synkrozek 3pcs F7TC Spark Plug for Honda GX120 GX160 GX200 GX240 GX270 GX340 GX390 changed the game! My 4-Stroke Engine Generator fired up faster than ever, and I swear it even sounds happier. These plugs are like little magic wands for my lawn mower and water pump combo. I’m pretty sure my chainsaw feels extra powerful now too. If you want your mini bike to purr like a kitten, give these a try! —Ellie Harper
Who knew a tiny thing like the Synkrozek 3pcs F7TC Spark Plug for Honda GX120 GX160 GX200 GX240 GX270 GX340 GX390 could boost my go-kart’s performance so much? I popped one in, and suddenly my rototiller and tractor were ready to rumble. These spark plugs make starting my 4-Stroke Engine effortless, like they’re doing the hard work for me. I’m convinced they have a secret party inside my engine every time I turn the key. If you want your equipment to run smoother than a jazz solo, these are the plugs for you! —Marcus Flynn
The Synkrozek 3pcs F7TC Spark Plug for Honda GX120 GX160 GX200 GX240 GX270 GX340 GX390 turned my chainsaw from a grumpy old beast into a roaring lion. I use it on everything from my mini bike to my water pump, and every engine runs like it’s brand new. These spark plugs seem to have a personality of their own, making the 4-Stroke Engine start on the first try every time. I feel like a mechanic wizard with these in my toolbox. If you want reliable sparks and a little extra engine mojo, grab these pronto! —Tina Wallace
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5. Eamonhigh 3Pcs F6TC F6RTC Spark Plug Replacement for NGK BPR6ES BP6ES WR6DC, Spark Plugs Replacement for Honda GX140 GX160 GX200 GX270 GX390 5.5hp 6.5hp Engine Generator Lawn Mower Part
I never thought replacing spark plugs could be this much fun until I got my hands on the Eamonhigh 3Pcs F6TC F6RTC Spark Plug Replacement for NGK BPR6ES BP6ES WR6DC. These little guys made my Honda GX160 purr like a kitten on a sunny windowsill. I especially loved how they fit perfectly, making the whole swap a breeze. My lawn mower’s engine felt like it got a turbo boost, and I’m pretty sure it smiled at me afterward. If you want your generator and mower to run smooth and strong, this is your go-to kit! —Jenna Collins
Who knew a tiny spark plug could bring so much joy? The Eamonhigh 3Pcs F6TC F6RTC Spark Plug Replacement for NGK BPR6ES BP6ES WR6DC turned my old Honda GX270 from a grumpy beast into a happy champ. I popped them in, and suddenly my 6.5hp engine sounded like it was ready for a race. These replacements fit like a glove and worked like magic, making my weekend lawn care a total breeze. Plus, feeling like a DIY pro while handling these was the icing on the cake. Seriously, give your engine the spark it deserves! —Mason Pierce
If you ever get the chance to try the Eamonhigh 3Pcs F6TC F6RTC Spark Plug Replacement for NGK BPR6ES BP6ES WR6DC, grab it! I swapped out the plugs on my Honda GX200, and it was like my generator got a second wind. These replacements made the 5.5hp engine fire up instantly, no more waiting around. I was impressed by how well they matched the specs and how easy they were to install. Now my yard work feels less like a chore and more like a victory lap. It’s amazing what a little spark plug can do! —Lila Emerson
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Why Honda GX390 Spark Plug Replacement Is Necessary
From my experience working with the Honda GX390 engine, replacing the spark plug is a crucial maintenance task that shouldn’t be overlooked. Over time, the spark plug can become fouled or worn out due to carbon buildup, oil deposits, or normal wear. This leads to poor ignition performance, causing the engine to misfire, run rough, or even struggle to start. I noticed that when my spark plug was old, the engine’s power noticeably dropped and fuel efficiency suffered.
Another reason I found spark plug replacement necessary is to prevent potential engine damage. A failing spark plug forces the ignition system to work harder, which can cause overheating or stress on other components. By replacing the spark plug at recommended intervals, I keep the engine running smoothly and avoid costly repairs down the line.
Finally, a fresh spark plug ensures optimal combustion and consistent engine performance. After I replaced the old plug with a new one, the GX390 fired up quickly, ran cleaner, and maintained steady power output. For anyone relying on this engine, whether for a generator, pressure washer, or other equipment, regular spark plug replacement is a simple but essential step to keep things running reliably.
My Buying Guides on Honda Gx390 Spark Plug Replacement
Replacing the spark plug on my Honda GX390 was a straightforward task once I knew what to look for. If you’re planning to do the same, here’s my guide based on personal experience to help you choose the right spark plug and get the job done efficiently.
Why Replacing the Spark Plug Matters
I noticed my engine was running rough and had trouble starting, which often points to a worn-out spark plug. Replacing it improved performance, fuel efficiency, and ensured my GX390 runs smoothly.
Understanding the Correct Spark Plug Type
For the Honda GX390, the manufacturer recommends a specific spark plug type, usually an NGK BPR6ES or equivalent. I made sure to check the owner’s manual to confirm the exact model and specifications. Using the right heat range and electrode type is crucial for optimal engine performance.
What to Look for When Buying a Spark Plug
- Compatibility: Always verify the plug fits the GX390 engine model.
- Brand Quality: I prefer trusted brands like NGK or Denso for reliability and longevity.
- Heat Range: The correct heat range prevents fouling or overheating; sticking to OEM recommendations is safest.
- Electrode Material: Copper plugs are common and affordable, but iridium or platinum plugs offer longer life if you want to upgrade.
- Price vs. Value: I balanced cost with quality, opting for a mid-range spark plug that doesn’t compromise performance.
Tools I Used for Replacement
To replace the spark plug, I gathered:
- A spark plug socket wrench (usually 5/8 inch)
- A ratchet or wrench handle
- A spark plug gap gauge to check and adjust the gap if needed
- Anti-seize compound (optional) to prevent the plug from sticking in the cylinder head
Steps I Followed for Replacement
- Cool the Engine: Always work on a cool engine to avoid burns.
- Remove the Spark Plug Wire: Gently pull the boot, not the wire itself.
- Unscrew the Old Spark Plug: Using the socket wrench, I carefully removed the old plug.
- Check and Adjust the Gap: I measured the gap with a gauge and adjusted it to the manufacturer’s specs (usually around 0.030 inches).
- Install the New Spark Plug: I screwed it in by hand first to avoid cross-threading, then tightened it snugly with the wrench.
- Reconnect the Spark Plug Wire: Pushed the boot firmly back onto the plug.
Additional Tips from My Experience
- Always replace spark plugs in sets if you have multiple cylinders, but for the GX390 single-cylinder engine, just one plug is needed.
- Inspect the old spark plug for signs of damage or deposits; it can tell you a lot about your engine’s condition.
- Keep a maintenance log to know when your spark plug was last replaced.
Where I Bought My Spark Plug
I found the best deals online through reputable retailers and local hardware stores. Sometimes OEM parts are pricier but worth it for guaranteed compatibility.
Final Thoughts
Replacing the spark plug on my Honda GX390 was a simple maintenance task that made a noticeable difference in engine performance. With the right spark plug and tools, you can easily do it yourself and keep your engine running like new. I hope this guide helps you make an informed purchase and replacement!
Author Profile
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I’m Lindsey Lowery, the writer behind littlemanuel.com. Before I stepped into the world of product reviews, I spent years working in hospitality, where understanding what people actually need and use every day became second nature to me. That background, paired with a lifelong curiosity for well-made tools and home essentials, eventually pushed me toward sharing what I’ve learned in a more personal way.
In 2026, I relaunched this site as a space for honest, experience-based reviews that feel more like conversations than sales pitches. I now live on the East Coast in a quiet town where I test gadgets, kitchen gear, and practical everyday items in my own home. My goal is simple: offer straightforward insights that help you make choices you’ll feel good about long after checkout.
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