NGK 3961 Spark Plug

NGK 3961 Standard Spark Plug Overview

NGK 3961 is a standard spark plug built with a copper center electrode core, nickel center electrode tip, and nickel ground electrode materials for consistent ignition performance. It uses a flat seat, 14 mm thread diameter, 13/16 hex size, and a pre-gap of .032 for straightforward service on the correct application.

As part of NGK’s Standard Spark Plug line, this plug reflects the brand’s OE-focused approach to ignition components. NGK has long supplied spark plugs for domestic and import vehicles, and part number 3961 is engineered to meet original equipment standards for durability and dependable operation.

Key Features

• Part number 3961 / BR8ES SOLID spark plug
• Copper center electrode core for stable conductivity
• Nickel center and ground electrode tip materials
• Standard ground electrode design with one ground electrode
• 5000 ohm resistance for ignition system noise control
• Flat seat design with 14 mm thread diameter
• 13/16 hex size and .75 reach
• Manufacturer heat range 8
• Pre-gapped to .032

Detailed Description

NGK 3961 is a standard replacement spark plug for engines that call for the BR8ES SOLID specification. The copper core supports reliable spark delivery, while the nickel electrode construction helps maintain steady performance under normal operating conditions. With its flat seat, non-removable nut terminal, and standard electrode configuration, this plug is built for direct service on the specified application.

For buyers searching for NGK 3961 spark plug, BR8ES SOLID, or a standard ignition tune-up part for motorcycle, marine, or small engine use, this plug offers the core dimensions and heat range needed for the correct engine setup. It is also a practical choice when replacing worn plugs on select Honda Civic applications where this part number is specified.

This part cross-references Atlantic Automotive Engineering 3961 for the same application.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Misfire from weak or inconsistent spark delivery
• Rough idle linked to degraded ignition performance
• Reduced throttle response from aged plug electrodes
• Maintenance replacement for engines calling for NGK 3961

Installation Notes and Tips

Verify the engine calls for BR8ES SOLID / NGK 3961 before installation. Confirm thread diameter, reach, seat type, and heat range against the service specification, and check the gap against the engine requirement if adjustment is needed. For fitment-based searches, this part is used in select Honda Civic applications and other vehicles or equipment that specify the same plug design.

Quality Assurance

NGK is a long-established OE spark plug supplier with extensive North American coverage across domestic and import vehicle applications. Part number 3961 is produced to support original equipment standards for durability and consistent ignition performance.