Mercury – NGK LFR4A-E Standard Spark Plug | Ignition Series | Nickel Alloy | 8M0157328

Overview

There’s something reassuring about the instant snap of a clean ignition. It’s that moment when you turn the key, hear the engine catch, and feel the whole boat come alive beneath you. A good spark plug is a small part of that moment, but any boater who’s spent enough time on the water knows how much depends on it. The Mercury Marine part 8M0157328 NGK LFR4A-E Spark Plug is one of those little essentials that quietly earns your trust. When your engine lights up smooth and strong — whether you’re heading out before sunrise or making a last-minute run across the lake — you’ll know this plug is doing exactly what it should.

Key Features

• NGK V-Power design with a precision-cut “V” center electrode.
• Nickel-alloy construction for consistent ignition performance.
• Pure alumina silicate ceramic insulator for better heat transfer and durability.
• Ribbed suppressor seal to reduce misfire and prevent flashover.
• Triple-sealed design for stronger resistance to fouling and leakage.
• Pre-gapped to engine-manufacturer specifications (always verify before installation).

Engine & Boat Compatibility

• Fits select Mercury engines requiring NGK LFR4A-E spark plugs.
• Common on fishing boats, pontoons, bass boats, aluminum rigs, and runabouts.
• Suitable for both mid-range and higher-output four-stroke platforms.
• Ideal for engines that see long idle times, trolling hours, or frequent start-stop cycling.

Performance & Practical Benefits

When you install this spark plug, the first difference you’ll notice is how cleanly the engine fires. The V-shaped electrode is engineered to direct the spark right to the hottest edge of the tip, which creates a crisp ignition that helps the engine breathe easier. That translates to smoother idle, better throttle response, and more dependable performance when you’re shifting between slow maneuvering and wide-open stretches.

The ceramic insulator is built to handle real marine heat — the kind you get after a long run in the summer or when you’re pushing the engine hard against current or chop. It also resists breakage, which matters when you’re working in tight spots under the cowling. The triple-seal design keeps moisture from creeping in, even when the weather turns wet or you’re dealing with heavy spray.

Installation is easy, even for boaters who like to handle their own tune-ups. With a proper spark plug socket and a gentle hand, you can swap old plugs for fresh ones in minutes. Once installed, you’ll feel the difference right away…that tight, responsive ignition that makes the whole boat feel more alive.

Why Buy OEM

With ignition parts, precision matters. Mercury Marine parts are engineered to meet exact heat ranges, electrode length, and ignition timing requirements for your specific engine. Aftermarket substitutes might look similar, but subtle differences in material or construction can lead to fouling, poor idle, and even long-term engine damage.

Using the genuine spark plug listed in your owner’s manual means you’re giving your engine exactly what it was built for — not something that “should work.” OEM parts deliver predictable longevity, easier starts, and more consistent running throughout the season. It’s the smart, practical choice for any boater who wants to avoid headaches on the water.

FAQ

Q1: Which Mercury engines does the NGK LFR4A-E fit?

It fits select Mercury engines that specify this exact plug. Checking your manual or current plug is the best confirmation.

Q2: What makes this plug better than aftermarket versions?

Its construction, heat management, and electrode design match Mercury’s ignition requirements perfectly.

Q3: How do I know it’s the correct replacement?

Use only the spark plug listed in your engine’s owner’s manual. If it calls for LFR4A-E, this is the correct replacement.

Q4: Is it suitable for both saltwater and freshwater?

Absolutely. Its corrosion-resistant plating and sealed design handle both environments well.

Q5: Is installation straightforward?

Yes — with the right socket and a gentle touch, most boaters can replace spark plugs in minutes.