NGK 7331 Spark Plug

NGK BP6HS Standard Spark Plug

The NGK 7331 spark plug is a standard replacement plug built around a copper center electrode, nickel tip materials, and a 1 ohm resistor for stable ignition performance. It uses a flat seat, 14 mm thread diameter, 13/16 hex, and a .028 pre-gap size for straightforward service on many small-engine and motorcycle applications, as well as select automotive uses.

As part of NGK’s Standard Spark Plug line, BP6HS focuses on OE-style construction and consistent operation. NGK’s long history as an OE supplier supports the product’s emphasis on durability, original-equipment standards, and broad application coverage. Part number 7331 is also identified by the NGK BP6HS reference.

Key Features

• Copper center electrode core with nickel center tip material
• Nickel ground electrode core with standard ground tip design
• 1 ohm resistor for ignition noise suppression
• Flat seat design with 14 mm thread diameter
• .028 pre-gap size for service-ready installation
• Removable nut terminal for common ignition wire connections
• Heat range 6 for specified engine applications
• NGK part number 7331 / BP6HS

Detailed Description

NGK BP6HS spark plug 7331 is built for engines that call for a standard copper-core plug with nickel electrodes and a flat-seat design. The 55 mm insulator height, .5 reach, and 13/16 hex size make it a direct-service style plug for applications that specify these dimensions. For buyers searching NGK 7331 spark plug, BP6HS spark plug, or NGK BP6HS replacement, this part provides the core specifications needed for accurate matching.

This spark plug is commonly searched for fitment-based applications such as motorcycle spark plug replacement, marine spark plug replacement, and small engine ignition service. It also appears in automotive cross-reference searches for vehicles using the same plug specification, including select Honda Civic and Toyota Corolla applications where the listed dimensions and heat range match the engine requirement.

This part cross-references Champion Spark Plug 312 and AP Exhaust 7331 for the same application.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Misfire conditions from weak or inconsistent spark delivery
• Rough idle and hesitation under acceleration
• Ignition noise concerns in resistor-equipped systems
• Service replacement needs for engines specified for BP6HS dimensions

Installation Notes and Tips

Verify the engine’s required thread diameter, reach, seat type, heat range, and terminal style before installation. Check the gap against the engine specification before use, since the listed pre-gap is .028 and some applications require a different setting. Confirm the plug matches the vehicle or equipment service manual, especially when searching by NGK 7331, BP6HS, or by make and model.

For fitment-based searches, confirm the exact application before ordering. This plug is commonly referenced in searches for Honda Civic spark plug replacement and Toyota Corolla spark plug replacement, but the final match should always follow the engine specification.

Quality Assurance

NGK is a long-established OE supplier with extensive North American coverage across automotive, motorcycle, marine, and small-engine ignition products. The BP6HS line is built to original-equipment standards for durability and consistent performance in specified applications.