NGK 2306 Spark Plug

NGK CPR8EA-9 Standard Spark Plug

NGK CPR8EA-9 is a standard spark plug built for consistent ignition performance in a wide range of small-engine and powersports applications. As part of NGK’s Standard Spark Plug line, it uses a copper core center electrode, nickel tip materials, and a 5,000 ohm resistor to support stable spark delivery and reduced electrical noise.

Key Features

• Part number: CPR8EA-9 / stock number 2306
• Standard ground electrode design with one ground electrode
• Copper core center electrode with nickel tip material
• Nickel ground electrode tip material
• 5/8 hex size, 10.00 mm thread diameter, .75 reach
• Flat seat type with .036 pre-gap size
• Manufacturer heat range 8
• Stud electrical terminal type

Product Details

The NGK Standard Spark Plug line is built around OE-style construction and broad application coverage. NGK has long supplied original equipment spark plugs for domestic and import vehicles in North America, and the CPR8EA-9 reflects that focus on durability, reliable ignition, and consistent operation. This spark plug is identified by part number CPR8EA-9 and stock number 2306, making it easy to match during service work on motorcycles, marine equipment, and small engines where the specified plug design is required.

For buyers searching by application, this plug is commonly referenced in fitment-based searches for Honda and other small-engine equipment using NGK CPR8EA-9. It is also a practical match when replacing worn plugs in engines that call for a 10 mm, flat-seat spark plug with a .036 gap and resistor construction.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Misfire from weak or inconsistent spark delivery
• Rough idle related to degraded ignition performance
• Electrical interference in ignition systems that use a resistor plug
• Service replacement needs for engines specified for NGK CPR8EA-9

Installation Notes and Tips

Verify the required thread diameter, reach, seat type, and heat range before installation. Check the gap against the engine specification before use, and confirm the terminal style matches the ignition lead or coil connection. For fitment-based searches, confirm the exact application by engine specification rather than vehicle name alone; this is especially important for Honda models and other equipment that may use multiple plug types.

Quality Assurance

NGK manufactures spark plugs to original equipment standards and supports a broad range of automotive, motorcycle, marine, and small-engine applications. The CPR8EA-9 is built with NGK’s established OE-focused engineering and manufacturing experience for dependable service performance.