The NGK Iridium Spark Plug Kit for Bajaj Dominar 400 is a specification-based ignition service kit designed for Dominar 400 engines equipped with a triple-spark cylinder head, where the factory-recommended spark plug combination is required.

Bajaj Dominar 400 engines use three spark plugs per cylinder — one centre spark plug and two side spark plugs — each with a specific plug code and design. This kit groups the correct NGK spark plugs into a single package to simplify replacement and ensure correct specification matching across all three plug positions.

This kit is intended strictly as a like-for-like replacement set, not as a modification or tuning upgrade.

Kit Contents & Spark Plug Positions

The kit includes the following NGK spark plugs:

• 1 × NGK LKAR8AI-9
  Centre spark plug position

• 2 × NGK CPR8EAIX-9
  Left and right side spark plug positions

Each spark plug in this kit serves a specific role within the Dominar 400’s triple-spark head and should be installed only in its designated position.

Spark Plug Construction Overview

NGK LKAR8AI-9 (Centre Plug)

The LKAR8AI-9 features a fine-wire iridium centre electrode, laser-welded for durability under confirmed heat cycles. Iridium is used due to its high melting point and resistance to electrode wear compared to conventional nickel-alloy materials.

This plug is specified by the manufacturer for the centre position in the Dominar 400’s triple-spark configuration and is designed to operate within the thermal range required for that position.

NGK CPR8EAIX-9 (Side Plugs)

The CPR8EAIX-9 spark plugs use NGK’s Iridium IX construction, incorporating a fine-wire iridium centre electrode paired with a conventional ground electrode design.

These plugs are specified for the left and right side positions of the Dominar 400 cylinder head. They are engineered to maintain consistent spark characteristics when used as specified, without altering engine tuning or ignition mapping.

Why a Matched Triple-Spark Kit Matters

In triple-spark engines, each spark plug position is designed with a specific heat range, reach, and electrode configuration. Mixing incorrect plug types or using mismatched specifications can result in improper ignition behaviour or uneven combustion.

This kit ensures:

• Correct spark plug code for each position

• Proper fitment across all three plug locations

• Simplified replacement without cross-referencing multiple listings

It does not change engine output, ignition timing, compression, or fuel delivery.

Intended Application & Compatibility

This NGK spark plug kit is intended for:

• Bajaj Dominar 400

  • BS3

  • BS4

  • BS6

Compatibility applies only to Dominar 400 engines that use the factory triple-spark configuration and specify LKAR8AI-9 and CPR8EAIX-9 spark plug codes.

It is not suitable for Dominar 250 or other Bajaj engines with different spark plug specifications.

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 plugs, actual replacement intervals depend on riding conditions, fuel quality, engine condition, and maintenance practices.

Installation should follow standard service procedures:

• Install each plug only in its specified position

• Use correct tightening torque

• Ensure clean threads and proper seating

Incorrect installation or plug placement may affect ignition behaviour or cause component damage.

Summary

The NGK Iridium Spark Plug Kit for Bajaj Dominar 400 is a specification-correct replacement set designed for triple-spark Dominar 400 engines. By bundling the required centre and side spark plugs into one kit, it simplifies maintenance while ensuring correct ignition component matching across all three spark plug positions.

This kit is intended strictly for engines that specify these NGK plug codes and should be installed according to manufacturer service guidelines.
Buyers are advised to verify spark plug specifications using the motorcycle manufacturer’s service manual before installation. Using the correct plug code and means correct fitment, heat range compliance, and reliable ignition system operation.