NGK LFR5A-11 Spark Plug

NGK Standard in the LFR5A-11 number, stock 6376. The solid copper core is doing the work here: it pulls heat out of the firing tip so the plug stays in its designed heat range across a broad load band, which is what a four stroke outboard sees between trolling and wide open throttle.

• NGK part LFR5A-11, stock number 6376
• Solid copper core center electrode with a nickel tip
• 5000 ohm resistor construction, standard ground configuration
• Corrosion-resistant plating for clean installation and removal
• Listed for Mariner, Mercury and Yamaha outboard applications among others

Confirm the plug number against your engine manual and change the set together. Mixed plug ages inside one bank hide a misfire instead of fixing it. Gap is set at the factory on most NGK plugs, so check it rather than bending it, and never pry on an iridium or fine wire tip.