NGK Laser Iridium Spark Plug - LKAR8AI

The NGK Laser Iridium LKAR8AI-9 (6706) is a high-performance spark plug specifically engineered for modern, high-revving liquid-cooled engines. It is the primary "Laser Iridium" choice for the KTM and Husqvarna single-cylinder platforms, as well as a popular center-plug upgrade for Bajaj triple-spark engines.

 

Unlike the standard Iridium IX series, the Laser Iridium line features a platinum ground electrode pad in addition to the iridium center tip, providing even greater longevity and a more stable spark gap over thousands of kilometers.

 

Key Technical Specifications

Feature	Specification	Impact
Model Code	LKAR8AI-9 (6706)	Direct OE replacement for KTM part 75039093000.
Heat Range	8	Medium-cold; ideal for high-compression, performance engines.
Thread Size	M12 x 1.25	12mm diameter with a fine pitch for secure fitment.
Reach	26.5 mm	Long-reach design; critical for deep-seated cylinder heads.
Hex Size	14 mm	Requires a slim 14mm spark plug socket for installation.
Gap	0.9 mm	Factory pre-set; handle with care to avoid damaging the fine tip.

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Core Performance Benefits

• Dual Precious Metal Design: The combination of an iridium center electrode and a platinum ground pad minimizes electrode wear. This ensures the spark gap remains consistent even under the extreme heat of a high-performance combustion chamber.

   

• Superior Ignitability: The fine-wire 0.6mm tip requires less voltage to create a spark, resulting in faster cold starts and a smoother, more stable idle.

   

• Anti-Fouling & Longevity: Specifically designed to resist carbon buildup, these plugs can comfortably last significantly longer than traditional copper or nickel plugs, making them ideal for touring and daily commuting.

   

• Sharper Throttle Response: By providing a more concentrated and precise spark, the engine burns fuel more efficiently, which translates to a crisper "snap" when you twist the throttle.

   

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Popular Fitment & Compatibility

The NGK LKAR8AI-9 is widely used across these specific models in India:

• KTM: Duke 125/200/250/390, RC 125/200/390, and Adventure 250/390 (BS3, BS4, and BS6 models).

   

• Husqvarna: Svartpilen 250/401 and Vitpilen 250/401.

   

• Bajaj (Center Plug Only): Dominar 250/400 and Pulsar NS200/RS200. Note that these bikes use three plugs; the LKAR8AI-9 is only used for the center position.

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Installation Note

Always install spark plugs on a cold engine to prevent damaging the aluminum threads in the cylinder head. For these M12 threads, the recommended torque is typically 10.8–14.5 lb. ft. into an aluminum head.