Mercury – ACDelco MR43LTS Marine Spark Plug | Specialty Marine Ignition Series | Nickel Alloy & Copper Core | 862029

Overview

There’s something satisfying about a marine engine that fires up instantly—a crisp spark, a steady rumble, and the quiet assurance that today’s trip is going to go smoothly. When you spend your weekends on the water, you start to appreciate the parts that make those easy starts possible. The Mercury Marine part number 862029 ACDelco MR43LTS Spark Plug is one of those small but essential components. It’s built to hold up in a harsh marine environment and deliver a consistent spark that keeps your engine running strong, whether you’re idling out of the marina or opening up the throttle across open water.

Key Features

• Specialty marine spark plug built with a nickel alloy tip and copper core for durability
• Ribbed suppressor seal helps reduce misfires and improve ignition stability
• Pre-gapped to manufacturer specifications for easy installation
• Designed to match Mercury Marine OEM ignition requirements
• Supports smooth starts, clean combustion, and reliable overall engine performance

Engine & Boat Compatibility

• Suitable for a wide range of Mercury and MerCruiser marine engines requiring MR43LTS plugs
• Commonly used in sterndrive and inboard platforms built by General Motors
• Ideal for cruisers, sport boats, runabouts, pontoon boats, and other recreational vessels
• Always verify fit using your owner’s manual recommendations

Performance & Practical Benefits

A great spark plug doesn’t call much attention to itself, but you notice the difference every time you start the engine. With the 862029 ACDelco MR43LTS installed, your ignition feels tight, responsive, and predictable. Engines start faster, idle smoother, and run cleaner thanks to the copper core’s excellent heat transfer and the nickel alloy’s ability to resist wear in demanding marine conditions.

Underway, the plug supports a steady spark that keeps your engine running at its best—whether you’re cruising at low speed, towing a wakeboarder, or heading into deeper water for a full day offshore. Combustion feels smoother, throttle response steadier, and overall performance more dependable.

What boaters really appreciate is how forgiving and straightforward installation is. Because the plug comes pre-gapped based on engine specifications, you simply remove the old plug, thread this one in, tighten it properly, and get back on the water. No complicated prep, no guesswork.

Durability is another highlight. The ribbed suppressor cap helps reduce flashover and supports long-term ignition stability, even in damp or salty environments. Instead of cleaning old plugs—an approach that rarely restores full performance—you’ll get stronger results and better protection by replacing them outright.

Why Buy OEM

Choosing a Mercury OEM-recommended spark plug means choosing a part engineered precisely for your engine’s ignition system. Aftermarket plugs may look similar, but slight differences in heat range, electrode material, or gap accuracy can lead to rough starts, reduced power, or long-term engine wear. With an OEM-fit MR43LTS plug, you’re getting the exact ignition performance Mercury intended—reliable, clean, and built for marine conditions. It’s a smart, inexpensive way to protect your investment and enjoy better performance every trip.

FAQ

Q1: Which engines use the 862029 MR43LTS Spark Plug?

It’s designed for Mercury and MerCruiser engines that specify MR43LTS plugs. Always confirm with your owner’s manual.

Q2: What makes this spark plug different from aftermarket versions?

It uses OEM-approved materials, proper heat range, and factory-set gapping to ensure reliable, accurate ignition.

Q3: How do I confirm this is the correct replacement?

Check your engine’s spark plug chart or owner’s manual for MR43LTS. If listed, this is the correct part number.

Q4: Can it be used in both freshwater and saltwater environments?

Yes—the materials and seal construction are designed for harsh, wet, and corrosive marine conditions.

Q5: Is installation easy for most boat owners?

Definitely. With a spark plug socket and basic hand tools, installation is simple and quick