NGK 9356 Iridium Racing Spark Plug for 2010-19 Honda CRF250R/2019 CRF250RX

Vehicle Fitment

• 2010-2019 Honda CRF250R (MX, Off-Road Motorcycle, 250 cc)
• 2019 Honda CRF250RX (MX, Off-Road Motorcycle, 250 cc)

Features

• Iridium-tipped fine-wire center electrode for high ignitability
• Nickel ground electrode with taper design for improved combustion
• Solid copper core for excellent heat conduction and dissipation
• Triple-seal design to minimize combustion gas leakage
• Ceramic insulator with corrugated ribs to prevent flashover
• Cold-rolled threads reduce risk of cross-threading during install
• Built-in resistor for EMI/RFI noise suppression
• Designed for high-performance and racing/off-road use

Specifications

• Brand: NGK Spark Plugs
• Part Number: 9356 (Service: R0451B-8)
• Electrode Tip Material: Iridium
• Center Electrode Core: Copper
• Ground Electrode Material: Nickel
• Heat Range: NGK 8
• Thread Diameter: 10 mm
• Reach: 26.5 mm (1.04")
• Seat Type: Flat/crush washer
• Pre-Gap: ~0.7 mm (0.028")
• Resistor: Yes (~5000 Ω)

Included Components

• 1x NGK 9356 Iridium Racing Spark Plug (R0451B-8)
• 1x Crush washer gasket

Product Description

The NGK 9356 Racing Iridium Spark Plug (R0451B-8) is engineered for high-performance off-road and motocross engines where rapid spark response and exceptional durability are critical. Featuring a fine-wire iridium center electrode and a tapered nickel ground electrode, this plug delivers reliable ignitability, efficient combustion, and improved throttle response under demanding conditions. Its solid copper core enhances heat dissipation, while the triple-seal design and high-grade ceramic insulator combat flashover and leakage for consistent firing performance.

Specifically verified for use on 2010-2019 *Honda CRF250R* motocross bikes and the 2019 *Honda CRF250RX*, this NGK plug meets or exceeds OEM ignition requirements for these high-revving 250 cc single-cylinder off-road machines. Ideal for racing applications or serious trail riding, the 9356 plug helps maintain smooth throttle progression and dependable spark delivery. Always consult the vehicle's official service manual for correct plug gap and torque specifications when installing.