NGK 5531 Spark Plug

NGK Standard Spark Plug DPR6EA-9

NGK 5531 is a standard spark plug built around a copper center electrode, nickel center tip, and nickel ground electrode for consistent ignition performance. With a 0.036 pre-gap, 5,000 ohm resistance, and a flat seat design, this plug supports stable combustion in a wide range of small-engine and automotive applications.

Standard Spark Plug Line

The NGK Standard Spark Plug line focuses on OE-style construction and dependable operation. Part number DPR6EA-9 is part of NGK’s long-running spark plug lineup, backed by the company’s experience as a major OE supplier for domestic and import vehicles in North America.

Key Features

• Part number DPR6EA-9, stock number 5531
• Copper center electrode core for reliable heat transfer
• Nickel center and ground electrode tip materials
• Standard ground configuration with one ground electrode
• 0.036 pre-gap size and 5,000 ohm resistance
• 12 mm thread diameter, 0.75 reach, flat seat
• 18 mm hex size and stud terminal type
• Manufacturer heat range 6

Detailed Description

NGK 5531 is a conventional spark plug engineered for steady ignition performance and OE-style fitment where the DPR6EA-9 specification is required. The copper core helps manage heat, while the nickel electrode materials support dependable spark delivery and long service life in normal operating conditions. For buyers searching for NGK DPR6EA-9, NGK 5531, or a standard replacement spark plug for Honda motorcycle and small-engine applications, this part provides the core dimensions and electrical characteristics needed for correct service.

This part cross-references Denso 4125 for the same application.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from weak or inconsistent spark output
• Misfire conditions tied to degraded electrode surfaces
• Reduced throttle response from poor combustion efficiency
• Maintenance replacement for vehicles using DPR6EA-9 specifications

Installation Notes and Tips

Verify 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-focused searches, this plug is commonly referenced for Honda motorcycle and small-engine service where DPR6EA-9 is specified, including Honda CB125 and Honda XR applications.

Quality Assurance

NGK manufactures spark plugs with OE-level production standards and broad coverage across automotive, motorcycle, marine, and small-engine applications. The brand’s North American OE supply background supports consistent dimensional accuracy and dependable performance for routine ignition service.