NGK Iridium IX Spark Plug (LKAR8AI-9) for KTM Duke / RC / Adventure 125-390 & Bajaj Dominar 250/400 / Pulsar NS200 / RS200 / AS200 / NS400Z – Centre Plug

The NGK Iridium IX LKAR8AI-9 spark plug is an OEM-spec ignition component designed for select KTM and Bajaj petrol engines where the LKAR8AI-9 spark plug specification is recommended. Manufactured by NGK to its Iridium IX construction standards, this spark plug is intended to provide consistent ignition performance and stable combustion when installed in compatible engines under normal operating conditions.

Spark plugs play a critical role in petrol engines by igniting the air–fuel mixture inside the combustion chamber. Correct ignition timing and spark stability are essential for controlled combustion, dependable starting, and predictable engine operation. The LKAR8AI-9 is engineered to meet these requirements when used in engines that specify this exact plug code.

Iridium IX Spark Plug Construction

The LKAR8AI-9 features a 0.6 mm fine-wire iridium centre electrode, laser-welded to improve electrode durability under repeated heat cycles. Iridium is selected for spark plug electrodes due to its high melting point and resistance to electrode erosion when compared to conventional nickel-alloy materials.

This spark plug also incorporates NGK’s ceramic insulator and resistor design, which are intended to support electrical insulation, suppress electromagnetic interference, and manage heat dissipation during engine operation. The plated metal shell is designed to resist corrosion and support durability during routine installation and removal.

The LKAR8AI-9 is manufactured as a like-for-like replacement component. It does not alter engine tuning, ignition timing, compression ratio, or fuel delivery characteristics.

Intended Application & Compatibility

The NGK LKAR8AI-9 spark plug is specified for select KTM and Bajaj motorcycle engines only where this exact plug code is listed in official service or maintenance documentation.

KTM – Direct Replacement Applications (BS4 & BS6)

• Duke 125

• Duke 200

• Duke 250

• Duke 390

• RC 125

• RC 200

• RC 390

• Adventure 250

• Adventure 390 (Gen 1 and BS6)

Bajaj – Centre Spark Plug (Triple-Spark Engines)

• Dominar 250 – Centre plug

• Dominar 400 – Centre plug

• Pulsar NS400Z – Centre plug

• Pulsar NS200 – Centre plug

• Pulsar RS200 – Centre plug

• Pulsar AS200 – Centre plug

Compatibility applies only where LKAR8AI-9 is the specified spark plug code. Engines using a different spark plug specification should not use this model, even if displacement or engine platform appears similar.

Important Note for Triple-Spark Engines

Certain Bajaj engines use a three-spark-plug cylinder head configuration. In these engines:

• 1 × LKAR8AI-9 is used as the centre spark plug

• 2 × CPR8EAIX-9 are used as the side spark plugs

This product listing is only for the centre spark plug (LKAR8AI-9). Buyers should confirm the correct quantity and plug positions before purchase.

Specification-Based Use

Spark plug codes define critical parameters including:

• Thread size and reach

• Heat range

• Electrode configuration

• Terminal type

Using the correct spark plug specification ensures proper fitment and correct thermal behaviour within the combustion chamber. Installing an incorrect spark plug may result in improper combustion or long-term engine issues.

The LKAR8AI-9 is not intended as a universal performance upgrade. It is designed strictly to meet the specification requirements of engines that call for this exact plug code.

Replacement & Service Considerations

Spark plugs are routine service components and should be replaced according to the motorcycle manufacturer’s recommended service intervals. While iridium spark plugs are generally designed for improved durability compared to conventional nickel plugs, actual replacement timing depends on riding conditions, fuel quality, engine condition, and maintenance practices.

The NGK LKAR8AI-9 is supplied as a single spark plug. Buyers should confirm the number of spark plugs required for their specific engine configuration before purchase.

Installation should follow standard service procedures, including correct tightening torque and clean thread conditions.

Summary

The NGK Iridium IX LKAR8AI-9 spark plug is an OEM-spec ignition component intended for select KTM and Bajaj motorcycles where this spark plug specification is recommended. Built with a fine-wire iridium centre electrode and NGK’s proven construction standards, it is designed to support stable ignition and reliable combustion when used as a direct replacement in compatible engines.

Correct compatibility verification and proper installation are essential before use.