Hyosung GT650R (2013-2017) Spark Plug Replacement Guide
Keep your GT650R's V-twin engine firing properly with the right new spark plugs.
- Your GT650R requires two spark plugs; NGK is the OEM brand and a reliable aftermarket choice.
- The front spark plug is difficult to access and requires moving the radiator, increasing labor time.
- Consider upgrading to Iridium plugs (NGK CR8EIX) for longer life, which is beneficial given the difficult installation.
- Symptoms like misfiring, backfiring, and hard starts are common indicators of failing spark plugs.
Signs of Failing Spark Plugs on Your GT650R
Worn spark plugs can cause a variety of issues. If you notice your bike isn't running as it should, bad plugs could be the culprit. Look for these common symptoms:
- Engine Misfires: The engine may hesitate or stumble, especially under acceleration. This can feel like a jerking or sputtering sensation.
- Backfiring: Unburnt fuel igniting in the exhaust can cause loud pops, particularly when the engine is warm or when letting off the throttle.
- Reduced Power: Your bike may feel sluggish and less responsive than usual.
- Hard Starting: Difficulty starting the engine, whether it's hot or cold, can be a sign of weak spark.
- Poor Fuel Economy: If you're filling up more often, inefficient combustion from bad plugs could be the reason.
- Rough Idle: An unstable or shaky idle is a classic symptom of a fouled or worn-out spark plug.
Known Issues & Recalls
For the 2013-2017 model years, there are no official recalls or Technical Service Bulletins (TSBs) from the NHTSA related to spark plugs for the Hyosung GT650R. Some owners in forums have reported issues with ignition coils or plug caps cracking, which can produce similar symptoms to a bad spark plug, such as a no-spark condition. If new plugs don't solve your ignition problem, these components are the next logical items to inspect.
Choosing the Right Aftermarket Spark Plug
For the GT650R, NGK is the original equipment (OEM) supplier, making them a trusted choice for aftermarket replacements. You have two main options:
- Standard NGK (CR8E): This is the OEM equivalent and provides reliable performance for everyday riding. They are affordable and work well, but have a shorter service life compared to iridium plugs.
- Iridium NGK (CR8EIX): Iridium plugs offer a longer lifespan and a more consistent, stable spark. This can lead to slightly better throttle response and improved starting. While they cost more upfront, their longevity often makes them a better value over time.
Pro Tip: Regardless of which brand you choose, always buy from a reputable supplier. The market is filled with counterfeit spark plugs that look genuine but perform poorly and can even damage your engine.
Cost of Replacing Hyosung GT650R Spark Plugs
| Part Type | Estimated Cost (Per Pair) |
|---|---|
| New Aftermarket (Champion, NGK) | $22 - $29 |
| New OEM (NGK) | $30 - $50 |
| Shop Labor | $100 - $180 |
Frequently Asked Questions
How many spark plugs does my GT650R need?
Your Hyosung GT650R has a V-twin engine, which means it has two cylinders and requires two spark plugs. You should always replace them as a pair.
Are iridium spark plugs worth the extra cost?
For most riders, yes. Iridium plugs, like the NGK CR8EIX, offer a significantly longer service life and more consistent performance than standard plugs. Given the difficulty of accessing the front spark plug on this bike, using a longer-lasting plug can save you from having to do the job again soon.
Why is the front spark plug so hard to change?
The front cylinder's spark plug is located behind the radiator. To get the necessary clearance to remove the ignition coil and the plug itself, you must at least partially dismount and move the radiator. The rear plug is much easier to access under the fuel tank.
Do new spark plugs need to be gapped?
While most high-quality plugs like NGK come pre-gapped, it is always a good practice to verify the gap before installation. The correct gap for the GT650R is between 0.7mm and 0.8mm. A simple feeler gauge is all you need to check it.
Technical Specifications
OEM Part Numbers: 09482-00456
Thread Size: 10mm, Hex Size: 16mm (5/8"), Spark Gap: 0.7mm - 0.8mm. Recommended Plugs: NGK CR8E (Standard), NGK CR8EIX (Iridium).
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Hyosung GT650R: