NGK Laser Iridium Spark Plug LKAR8AI-9 (6706) – KTM Duke/RC/Adventure 125–390, Husqvarna 401 – Center Plug Upgrade for Pulsar NS/RS/AS200 & Dominar 250/400

If your KTM, Husqvarna or Bajaj triple-spark bike is starting harder, idling rough or feeling dull on top-end, the stock plug is usually the first suspect. NGK LKAR8AI-9 (Stock #6706) Laser Iridium is a premium direct-fit upgrade plug that keeps the same dimensions and heat range as the OE LKAR8A-9, but adds a 0.6 mm fine-wire iridium center electrode with a platinum ground pad for a stronger, cleaner spark and a much longer service life.

The plug uses an M12 × 1.25 thread, 26.5 mm reach, 14 mm hex, gasket seat, 0.9 mm factory gap and 5 kΩ resistor, exactly matching KTM/Husqvarna part 75039093000 and NGK 6706 specs. It drops straight into KTM Duke/RC/Adventure 125–390 singles and Husqvarna 401, and is widely used as the center plug upgrade on Bajaj Pulsar NS/RS/AS200 and Dominar 250/400 triple-spark engines for crisper throttle and smoother cruising.

Compared to standard plugs, riders typically feel easier cold starts, cleaner combustion, improved throttle response and more stable performance under load, especially on hot Indian highways or when riding with luggage.

Why buy from Under The Hood?
You get 100% genuine NGK Laser Iridium stock, fresh inventory, careful packaging, and real-world guidance from a workshop that actually tunes and services these bikes—not just an online seller.

Key Features

• Genuine NGK Laser Iridium – Original plug LKAR8AI-9 / 6706 with iridium center and platinum ground electrodes for long life and consistent spark.

• Correct KTM/Husqvarna Spec – M12 × 1.25 thread, 26.5 mm reach, 14 mm hex, gasket seat, 0.9 mm factory gap, 5 kΩ resistor – matches OEM part 75039093000.

• Fine-Wire 0.6 mm Iridium Tip – Concentrates the spark, needs less voltage and resists fouling for smoother idle and stronger ignition at high rpm.

• Platinum Ground Pad – Laser-welded ground electrode with platinum pad reduces wear and maintains gap accuracy for many more kilometres than copper plugs.

• Direct Fit for KTM 125–390 Singles & Husqvarna 401 – Used by KTM/Husqvarna as OE-equivalent spark plug on many 125/200/250/390 single-cylinder models.

• Center Plug Upgrade for Bajaj Triple-Spark – Widely adopted as the center plug on Pulsar NS/RS/AS200 and Dominar 250/400 for crisper response and cleaner burn (check manual before upgrade).

• Improved Throttle Response & Efficiency – Iridium construction and precise heat range 8 help improve combustion stability, which can translate to smoother acceleration and potential fuel efficiency gains.

• Longer Service Life – Laser Iridium design typically lasts 2× or more than standard nickel plugs when maintained correctly, reducing plug-change frequency.

• Global OEM & Aftermarket Support – The same code is used worldwide across KTM/Husqvarna models, making future replacements easy to source.

• Under The Hood Assurance – Supplied with GST invoice, shipped safely, and backed by enthusiasts who can actually help you choose plugs and troubleshoot issues.

 Compatibility Table

NS 400  COMPATABLE 

Caution: For bikes marked ❓, always cross-check your owner’s manual or OE plug code (often LKAR8A-9 / CPR8EA-9 equivalents). If in doubt, contact Under The Hood with your bike’s exact model year and variant before ordering.

Variants

This listing is for one specific model:

• NGK LKAR8AI-9 (6706) Laser Iridium – Single Plug

  • Best for riders who want an OE-dimension, heat-range-correct upgrade with longer life and sharper response, without experimental heat-range changes.

Side plugs for triple-spark Bajaj engines (e.g., NGK CPR8EAIX-9) are not included and should be purchased separately if needed.

 What’s in the Box

• 1 × NGK LKAR8AI-9 (6706) Laser Iridium Spark Plug in original NGK packaging

Installation & Maintenance Notes

• Always install on a cold engine to avoid thread damage.

• Plug comes pre-gapped at 0.9 mm; normally no adjustment is needed. If your manual specifies a different gap, adjust gently and avoid prying on the fine iridium tip.

• Use a 14 mm plug socket and torque to manufacturer spec; avoid over-tightening M12 threads in aluminium heads.

• Recommended to inspect at each major service; under normal use, a Laser Iridium plug can comfortably outlast two standard plug intervals when the engine is healthy.

• If you ride a lot in traffic, extreme heat or dusty conditions, check more often for carbon build-up or oil fouling.

• When replacing in triple-spark Bajaj engines, only change the center plug to LKAR8AI-9; side plugs use a different code and must match OEM spec.

 FAQs

Q1. Will NGK LKAR8AI-9 fit my KTM Duke/RC/Adventure 125–390?
Yes. NGK LKAR8AI-9 is widely listed as the correct Laser Iridium plug for KTM 125/200/250/390 single-cylinder Duke, RC and Adventure models and matches KTM OE part 75039093000. For the very latest “Gen3” or future BS7 models, always double-check the owner’s manual or OE plug code.

Q2. Is this better than the stock plug?
In most cases, yes. It keeps the same heat range and dimensions as the stock plug but uses a fine-wire iridium center and platinum ground pad. That gives a stronger, more consistent spark, better combustion stability and a longer service life when the engine is healthy and properly tuned.

Q3. Can I use this in Pulsar NS/RS/AS200 or Dominar 250/400?
Many riders and retailers use LKAR8AI-9 as the center plug upgrade on these Bajaj triple-spark engines, with positive feedback on smoothness and throttle response. However, OE Iridium IX charts also list CPR8EAIX-9 as the center plug for some Dominar/Pulsar models, so always verify against your manual or existing plug code before ordering.

Q4. Will this affect mileage or engine warranty?
Because LKAR8AI-9 matches the OE heat range and dimensions, it is generally safe as a replacement plug. When used on OEM-listed models and installed correctly, it should not negatively affect warranty. Incorrect heat range, cross-threading or over-tightening, however, can cause issues—so follow manufacturer guidelines or have it fitted by a professional.

Q5. How long does an NGK Laser Iridium plug last?
Service life depends on fuel quality and riding style, but Laser Iridium plugs are designed to last significantly longer than standard nickel plugs—often up to twice the interval when the engine is in good condition and the plug is kept clean.