NGK LFR4A-E Standard Marine Spark Plug, Copper Core, 5/8 Inch Hex

The NGK LFR4A-E is a standard marine spark plug built on NGK's proven copper-core design, giving boat owners a reliable, factory-style replacement plug for scheduled engine maintenance. A solid copper core runs through the center electrode to provide strong heat dissipation and conductivity across a broad heat range, while corrosion-resistant plating on the shell and threads keeps installation and removal easy even after time in a marine environment. The plug uses a semi-surface discharge ground configuration with a nickel ground electrode and a nickel center electrode tip, and it carries a 5/8 inch hex size for use with common spark plug sockets. Internally, NGK builds this plug with a pure alumina silicate ceramic insulator for strength and heat transfer, and a ribbed suppressor seal along with a triple seal to resist spark flashover, misfire, and leakage. NGK rates the plug at 10k ohm resistance for suppression of ignition interference. As with any spark plug, always confirm this is the correct plug called for in your engine's owner or maintenance manual before installing, since using the wrong plug can reduce performance and fuel economy or cause engine damage. Replacing spark plugs on schedule, rather than cleaning and reusing old ones, helps maintain consistent starting and running performance.

Specifications

• Brand: NGK
• Manufacturer Part Number: LFR4A-E
• Product Type: Standard Spark Plug
• Resistance: 10k Ohm
• Ground Configuration: Semi-Surface Discharge
• Ground Electrode Core Material: Nickel
• Center Electrode Core Material: Copper
• Center Electrode Tip Material: Nickel
• Hex Size: 5/8 inch
• Weight: 0.15 pounds
• UPC: 087295164990

Frequently Asked Questions

What is the NGK LFR4A-E spark plug used for? The NGK LFR4A-E is a standard marine spark plug used to replace worn spark plugs during routine engine maintenance on inboard, sterndrive, or outboard marine engines that call for this plug in their owner or maintenance manual.

What electrode material does the LFR4A-E use? This NGK plug has a copper center electrode core with a nickel center electrode tip and a nickel ground electrode, paired with a solid copper core for heat dissipation and conductivity.

What hex size wrench does the LFR4A-E spark plug need? The NGK LFR4A-E has a 5/8 inch hex size, so it can be installed and removed with a standard 5/8 inch spark plug socket.

What is the resistance rating of the LFR4A-E? The NGK LFR4A-E carries a 10k ohm resistance rating, which helps suppress ignition interference.

Is the LFR4A-E an iridium or standard spark plug? The LFR4A-E is one of NGK's standard spark plugs, using a copper core and nickel electrode materials rather than an iridium-tipped design.

What ground electrode configuration does this plug use? The NGK LFR4A-E uses a semi-surface discharge ground configuration with a nickel ground electrode.

How much does the NGK LFR4A-E spark plug weigh? The NGK LFR4A-E weighs 0.15 pounds.

How is the LFR4A-E plug sealed against leakage? NGK builds the LFR4A-E with a ribbed suppressor seal and a triple seal to resist spark flashover, misfire, and leakage at the plug boot.

Should I clean and reuse my old spark plug instead of buying an LFR4A-E? No, NGK recommends replacing worn plugs with a new plug like the LFR4A-E rather than cleaning and reusing old ones, since a new plug provides more consistent performance.

How do I know if the LFR4A-E is the right plug for my engine? Check your engine's owner or maintenance manual for the exact spark plug it specifies before installing an NGK LFR4A-E, since using the wrong plug can reduce performance, reduce fuel economy, or cause engine damage.

What insulator material is used in the LFR4A-E? The NGK LFR4A-E uses a pure alumina silicate ceramic insulator, which provides strength, reduces breakage, and improves heat transfer.

Is the NGK LFR4A-E a genuine NGK part? Yes, the LFR4A-E is a genuine NGK standard spark plug, part number LFR4A-E.