NGK BR6FS Spark Plug 4323 - Replaces Mercury 33-59571B, Fits Mercruiser 2000-2006, OMC 1982-1993

The NGK BR6FS is a standard NGK spark plug built on the same design NGK has supplied to original equipment manufacturers for decades. It uses a solid copper core center electrode for superior heat dissipation, strong conductivity, and a broad operating heat range, paired with a nickel center electrode tip and a nickel standard ground electrode. The plug carries a 5000 Ohm resistance rating and is finished with corrosion-resistant plating that keeps installation and removal easy even after extended service in a marine engine bay.

The NGK BR6FS (stock number 4323) is engineered for marine and marine-derived engine applications and fits Indmar engines up to 1997, Kodiak engines from 1999-2000, Marine Power engines from 1975-2000, Mercruiser engines from 2000-2006, and OMC engines from 1982-1993. It is a direct cross-reference to the Quicksilver/Mercury 33-59571B, Yamaha BR6-FS000-00-00, and Evinrude/Johnson 0509573 and 0503708 spark plugs, so it can be used as a like-for-like replacement in those applications. Always confirm the correct plug and gap setting against your engine's maintenance manual before installation, since using the wrong plug can reduce performance, hurt fuel economy, or damage the engine.

Specifications

• Brand: NGK
• Manufacturer Part Number: BR6FS
• Resistance: 5000 Ohm
• Ground Configuration: Standard
• Ground Electrode Core Material: Nickel
• Center Electrode Core Material: Copper
• Center Electrode Tip Material: Nickel
• Weight: 0.15 pounds
• UPC: 087295143230

Fitment

• Indmar - to 1997
• Kodiak - 1999-2000
• Marine Power - 1975-2000
• Mercruiser - 2000-2006
• OMC - 1982-1993

Replaces (OEM)

• Quicksilver / Mercury 33-59571B
• Yamaha BR6-FS000-00-00
• Evinrude / Johnson 0509573
• Evinrude / Johnson 0503708

Frequently Asked Questions

What engines does the NGK BR6FS spark plug fit? The NGK BR6FS (stock number 4323) fits Indmar engines up to 1997, Kodiak engines from 1999-2000, Marine Power engines from 1975-2000, Mercruiser engines from 2000-2006, and OMC engines from 1982-1993.

Is the NGK BR6FS a direct replacement for the Mercury 33-59571B spark plug? Yes, the NGK BR6FS cross-references directly to the Quicksilver/Mercury 33-59571B spark plug.

What OEM part numbers does the NGK BR6FS replace? The NGK BR6FS replaces Quicksilver/Mercury 33-59571B, Yamaha BR6-FS000-00-00, and Evinrude/Johnson 0509573 and 0503708.

What is the resistance rating of the NGK BR6FS? The NGK BR6FS carries a 5000 Ohm resistance rating.

What materials make up this spark plug? The NGK BR6FS uses a copper center electrode core for heat dissipation and conductivity, with a nickel center electrode tip and a nickel standard ground electrode.

How much does the NGK BR6FS spark plug weigh? The NGK BR6FS weighs 0.15 pounds.

Is the NGK BR6FS a genuine NGK part? Yes, the BR6FS (stock number 4323) is a genuine NGK Standard spark plug, not an aftermarket copy.

Does the NGK BR6FS fit Yamaha engines? The NGK BR6FS cross-references to the Yamaha BR6-FS000-00-00 spark plug as a replacement part number, though Yamaha is not listed among its direct engine fitments of Indmar, Kodiak, Marine Power, Mercruiser, and OMC.

What ground electrode configuration does the NGK BR6FS use? The NGK BR6FS uses a standard ground electrode configuration.

Will the NGK BR6FS work in a 2003 Mercruiser? Yes, the NGK BR6FS is listed to fit Mercruiser engines from 2000-2006, which covers a 2003 model.

What is included when I order the NGK BR6FS? Each order includes one NGK BR6FS spark plug (stock number 4323).

Does the NGK BR6FS suppress radio-frequency interference? The NGK BR6FS carries a 5000 Ohm resistance rating, which is the resistor value used to suppress radio-frequency interference on resistor-type spark plugs.