NGK 5531 DPR6EA-9 Standard Spark Plug for Mercury, Mariner, and Yamaha Outboards

The NGK 5531 (DPR6EA-9) is a standard nickel-core spark plug built on NGK's OE cornerstone design, delivering reliable ignition performance across a broad heat range. It uses a solid copper core in the center electrode for superior heat dissipation and conductivity, paired with a nickel-plated ground electrode and center electrode tip. This corrosion-resistant plating keeps threads and electrodes protected in service and makes the plug easier to install and remove during routine maintenance. The plug has a Standard ground electrode configuration and measures 5000 ohm resistance for suppression of ignition noise.

This plug is designated for a range of outboard, ATV, and motorcycle applications, including Mercury and Mariner outboard motors and Yamaha outboards, as well as select Honda, Kawasaki, and Suzuki powersport engines. Always check your engine and maintenance manual to confirm the DPR6EA-9 is the correct plug for your specific engine, since installing the wrong plug can reduce performance, hurt fuel economy, or damage the engine.

Specifications

• Brand: NGK
• Manufacturer Part Number: 5531
• NGK Part Number: DPR6EA-9
• UPC: 087295155318
• Resistance: 5000 Ohm
• Ground Configuration: Standard
• Ground Electrode Core Material: Nickel
• Center Electrode Core Material: Copper
• Center Electrode Tip Material: Nickel
• Insulator Material: Ceramic
• Quantity: 1 spark plug per pack
• Weight: 0.15 pounds

Fitment

• Outboard - Mariner, model years 2002-1995
• Outboard - Mercury, model years 2006-1995
• Outboard - Yamaha, model years 2005-1995
• ATV - Honda, model years 2001-1998
• Motorcycle - Honda, model years 2007-2004
• Motorcycle - Kawasaki, model years 2008-1999
• Motorcycle - Suzuki, model years 2005-2004

Frequently Asked Questions

What is the NGK 5531 spark plug also known as? NGK 5531 is the stock number for the NGK DPR6EA-9 standard spark plug, so the two numbers refer to the same part.

Does the NGK 5531 (DPR6EA-9) fit Mercury outboard motors? Yes, the DPR6EA-9 is designated for Mercury outboard engines covering model years 2006-1995, as well as Mariner outboards from 2002-1995.

Is the NGK 5531 spark plug compatible with Yamaha outboards? Yes, the NGK DPR6EA-9 (5531) covers Yamaha outboard applications for model years 2005-1995.

What resistance rating does the NGK DPR6EA-9 spark plug have? The DPR6EA-9 carries a 5000 ohm resistance rating, which helps suppress ignition noise during operation.

What materials are used in the NGK 5531 spark plug electrodes? The center electrode core is copper for heat dissipation, and both the ground electrode and center electrode tip are nickel with corrosion-resistant plating.

Is the NGK 5531 a standard or premium spark plug? The 5531 (DPR6EA-9) is one of NGK's Standard spark plugs, using a solid copper core rather than an iridium or platinum tip.

Does one NGK 5531 order include multiple spark plugs? Each NGK 5531 (DPR6EA-9) order is a single spark plug, so multi-cylinder engines will need one plug per cylinder.

Does the NGK DPR6EA-9 fit any powersport vehicles besides outboards? Yes, in addition to Mercury, Mariner, and Yamaha outboards, the DPR6EA-9 is designated for Honda ATVs (2001-1998) and Honda, Kawasaki, and Suzuki motorcycles within the years listed for each brand.

Why is the ground electrode plating important on the NGK 5531? The nickel plating on the DPR6EA-9's ground electrode and center electrode tip resists corrosion, which keeps the plug easier to remove and install during future maintenance.

How much does the NGK 5531 spark plug weigh? The NGK DPR6EA-9 (5531) spark plug weighs 0.15 pounds.

How do I know if the NGK 5531 is the right plug for my engine? Check your engine's maintenance manual for the manufacturer's recommended spark plug before installing the DPR6EA-9 (5531), since using an incorrect plug can reduce performance, lower fuel economy, or cause engine damage.