NGage DH7RTII-8 Double Iridium Spark Plug for Royal Enfield J-Series 350 (BS4 & BS6)
Engineered for the Royal Enfield J-Series 350 Platform
The NGage DH7RTII-8 Double Iridium Spark Plug is specified for Royal Enfield motorcycles built on the J-Series 350 engine platform. This platform introduced a revised engine architecture featuring updated combustion chamber geometry, fuel injection systems, and refined ignition requirements compared to earlier Royal Enfield engine generations.
The DH7RTII-8 is listed by NGage as a direct replacement spark plug for J-Series 350 motorcycles, covering both BS4 and BS6 compliant models within this platform. It is engineered to align with the ignition characteristics and operational requirements defined for these engines.
This spark plug is not intended for older UCE engines or non–J-Series Royal Enfield platforms.
Understanding the J-Series 350 Platform
Royal Enfield’s J-Series 350 engine underpins multiple current-generation motorcycles sharing a common engine and ignition system architecture. The platform includes:
Revised cylinder head design
Updated combustion chamber characteristics
Fuel-injected system configuration
BS4 and BS6 production variants
Because these motorcycles share common ignition specifications, NGage lists the DH7RTII-8 as a unified replacement option for the J-Series family.
Correct platform identification is essential. Spark plug mismatch can affect ignition stability, combustion efficiency, and long-term engine reliability. This listing applies strictly to the J-Series 350 motorcycles specified in the compatibility section below.
Double Iridium Construction
The DH7RTII-8 belongs to NGage’s Double Iridium spark plug lineup. “Double Iridium” refers to the use of iridium material on both the center electrode and the ground electrode.
Iridium is widely used in modern spark plug design due to its:
High melting point
Resistance to electrode wear
Ability to maintain structural integrity under repeated ignition cycles
By applying iridium on both electrodes, the design aims to support consistent spark generation across regular operating conditions. Double iridium construction is commonly used in engines requiring stable ignition performance over extended service intervals.
NGage does not publish specific electrode dimensions, preset gap values, or manufacturer-defined service intervals for this part number, and no additional performance claims are implied.
This spark plug is positioned strictly as a premium replacement component within its specified application.
BS4 and BS6 Compatibility
According to NGage product material, the DH7RTII-8 spark plug is compatible with both BS4 and BS6 compliant Royal Enfield J-Series motorcycles. This ensures coverage across production years spanning the emission transition period, provided the motorcycle belongs to the J-Series 350 platform.
No claims are made regarding emission reduction benefits, fuel economy improvement, horsepower gains, or performance tuning enhancements. The DH7RTII-8 is intended strictly as a replacement spark plug that aligns with manufacturer-specified ignition requirements.
Manufacturing Origin
The NGage DH7RTII-8 spark plug is manufactured in Japan, as stated by NGage. No additional manufacturing process details, certifications, or performance endorsements are published by the manufacturer beyond this information.
Country of origin is specified strictly for product identification purposes.
Intended Use
The DH7RTII-8 spark plug is intended for routine replacement during scheduled maintenance intervals as recommended by Royal Enfield. It is suitable for:
Daily commuting
Highway riding
General road use
Scheduled spark plug service
This spark plug is not marketed as a racing component, track-only ignition system, or specialized tuning upgrade.
Correct installation and torque specification should always follow the Royal Enfield service manual guidelines.
Fitment Accuracy & Platform Restriction
Spark plug selection must match engine platform requirements precisely. The DH7RTII-8 is intended exclusively for Royal Enfield J-Series 350 motorcycles listed below.
It should not be installed on:
Older UCE 350 engines
Royal Enfield 500 cc engines
Other Royal Enfield platforms not listed
Incorrect spark plug installation may affect ignition performance and engine operation.
Compatibility – Royal Enfield J-Series 350
Compatible with:
Royal Enfield Classic 350 (Reborn)
Royal Enfield Bullet 350 (Reborn)
Royal Enfield Meteor 350
Royal Enfield Hunter 350
Compatibility applies strictly to J-Series 350 models.
Variant Clarification
This listing includes:
NGage DH7RTII-8 Double Iridium Spark Plug only
“Double Iridium” refers specifically to iridium usage on both the center and ground electrodes.
No alternate heat ranges, configurations, or material variants are included in this listing.
Product Specifications
Brand: NGage
Part Number: DH7RTII-8
Spark Plug Type: Double Iridium
Vehicle Compatibility: BS4 & BS6 J-Series 350
Country of Manufacture: Japan
Application: Motorcycle spark plug
Installation & Usage Notes
Install only on Royal Enfield J-Series 350 motorcycles listed above
Follow Royal Enfield service manual torque specifications
Install on a cold engine
Follow standard spark plug installation procedures
Professional installation is recommended if unsure about torque settings or spark plug replacement procedures.
Summary
The NGage DH7RTII-8 Double Iridium Spark Plug is a platform-specific replacement component engineered for Royal Enfield J-Series 350 motorcycles. Manufactured in Japan and designed with double iridium electrode construction, it aligns with the ignition requirements of BS4 and BS6 compliant J-Series engines.
It is intended for routine maintenance replacement, maintaining ignition consistency within manufacturer-specified parameters.
Platform-specific fitment. Double iridium construction. J-Series ignition compatibility.
