NGage Double Iridium Spark Plug (B8RII-8) – Jawa 42, Bobber 42, 350, 42 FJ & Yezdi Roadster, Adventure, Scrambler

The NGage B8RII-8 Double Iridium Spark Plug is a precision ignition component developed for select Jawa and Yezdi motorcycles built on modern, fuel-injected single-cylinder platforms. Manufactured in Japan, this spark plug is part of NGage’s Double Iridium series and is specified for use in both BS4 and BS6 compliant motorcycles, as stated by the manufacturer.

This listing focuses exclusively on its application for the Jawa and Yezdi models listed in NGage’s official compatibility chart for part number B8RII-8. It is intended as a direct replacement spark plug for these motorcycles, without modification.

Designed for Jawa & Yezdi Motorcycles

NGage specifies the B8RII-8 spark plug for a defined group of Jawa and Yezdi motorcycles that share common ignition system requirements.

The following models are listed by NGage for use with the B8RII-8 spark plug:

Jawa

• Jawa Forty Two

• Jawa Bobber 42

• Jawa 350

• Jawa 42 FJ

Yezdi

• Yezdi Roadster

• Yezdi Adventure

• Yezdi Scrambler

These motorcycles represent modern, liquid-cooled and air-cooled single-cylinder platforms developed for contemporary combustion and emission standards. NGage lists the same B8RII-8 specification across all of these models, indicating alignment with their ignition system design and operating parameters.

For these motorcycles, the B8RII-8 is intended to function as a like-for-like replacement for the factory-specified spark plug type. It is not positioned as a tuning component or a modification-driven upgrade, but as a specification-correct ignition part for routine service or replacement.

Double Iridium Spark Plug Construction

NGage classifies the B8RII-8 as a Double Iridium spark plug, meaning iridium material is used on both the center electrode and the ground electrode.

Iridium is used in modern spark plug construction due to its high melting point and resistance to electrode erosion during repeated ignition cycles. This construction approach is commonly applied in motorcycles with high-energy ignition systems and tightly controlled combustion environments.

The double-iridium configuration is intended to maintain consistent electrode geometry over extended operating periods under normal riding conditions. NGage does not publish electrode dimensions, spark-gap values, heat-range explanations, or service-interval figures for this model.

BS4 and BS6 Compatibility

NGage specifies that the B8RII-8 spark plug is compatible with both BS4 and BS6 vehicles. This makes it suitable for use across production years that fall before and after the BS6 emission-standard transition, provided the motorcycle is included in the compatibility list.

For the Jawa and Yezdi motorcycles listed above, this ensures suitability across emission-compliant variants without requiring a change in spark plug specification.

No emission-reduction, fuel-efficiency, or tuning claims are made for this product.

Manufacturing Origin

The B8RII-8 spark plug is manufactured in Japan, as stated by NGage.

NGage does not publish further information regarding production processes, certifications, or testing standards for this model. The country of manufacture is provided here as factual product information only.

Intended Use

The NGage B8RII-8 is intended for routine replacement during scheduled maintenance or spark-plug service intervals recommended by the motorcycle manufacturer. It is suitable for everyday road use on the Jawa and Yezdi motorcycles listed below within standard operating conditions.

This spark plug is not positioned by NGage as a racing-only, track-specific, or specialized tuning component.

Fitment Accuracy

Correct spark plug selection is critical for engine operation and long-term reliability.

The B8RII-8 should be installed only on motorcycles listed in the compatibility section below. Use on non-listed motorcycles is not recommended.

Compatibility

As per NGage official compatibility chart for part number B8RII-8:

Jawa Motorcycles

• Jawa Forty Two

• Jawa Bobber 42

• Jawa 350

• Jawa 42 FJ

Yezdi Motorcycles

• Yezdi Roadster

• Yezdi Adventure

• Yezdi Scrambler

Variant Explanation

This listing is for NGage B8RII-8 Double Iridium Spark Plug only.

• “Double Iridium” refers to iridium usage on both the center and ground electrodes.

• This part number represents a single manufacturer-defined specification.

• No alternate heat ranges or material variants are included in this listing.

Specifications 

• Brand: NGage

• Part Number: B8RII-8

• Spark Plug Type: Double Iridium

• Vehicle Compatibility: BS4 & BS6

• Country of Manufacture: Japan

• Application: Motorcycle spark plug

Installation / Usage Notes

• Install only on Jawa and Yezdi motorcycles listed in the compatibility section.

• Follow the motorcycle manufacturer’s service-manual torque specifications and standard spark-plug installation procedure.

• Install on a cold engine.