Mercury – NGK IZFR5G Laser Iridium Spark Plug | Ignition Component | Steel & Ceramic | 889597Q

Overview

There’s a kind of quiet trust that builds between you and your engine once you’ve found a spark plug that never hesitates. The NGK IZFR5G Laser Iridium plug feels like one of those dependable little parts you install and forget — because it just works. You turn the key, the motor fires, and the day gets going without a second thought. Whether you’re easing out of a no-wake zone or pushing toward open water, it’s comforting knowing the ignition is as clean and steady as the sunrise over the tide.

Key Features

• Laser Iridium center electrode for strong, consistent ignition
• Copper core construction for steady firing and long service life
• Pure alumina silicate ceramic insulator for superior strength and heat transfer
• Trivalent metal plating for corrosion resistance and non-seizing installation
• Ribbed suppressor seal to prevent flashover and reduce misfires
• Pre-gapped to Mercury specifications (gap should still be verified before installation)

Engine & Boat Compatibility

• Fits select Mercury and Mercury Marine outboards requiring NGK IZFR5G spark plugs
• Suitable for a wide range of FourStroke engines
• Works well on bass boats, pontoons, center consoles, bay boats, and nearshore fishing boats
• Compatible with engines designed for Iridium ignition components

Performance & Practical Benefits

A good spark plug changes how your whole engine feels — not just how it starts. This Laser Iridium plug delivers a crisp, clean ignition that helps the motor settle into a smooth idle and climb through the throttle range with confidence. You’ll notice fewer stumbles coming out of turns, steadier mid-range cruising, and more predictable acceleration when you need to push across a windy stretch.

The ceramic insulator sheds heat quickly, protecting the plug during long hours of idling, trolling, or slow runs along the shoreline. The Iridium tip resists wear even after heavy use, keeping the spark consistent over time. And because it fights off fouling, you won’t spend your Saturday pulling apart the cowling when you’d rather be casting a line or heading toward your favorite anchorage.

Why Buy OEM

Mercury Marine parts are built around exact ignition timing and combustion requirements. Aftermarket plugs might fire, but they rarely provide the long-term consistency needed to protect engine performance. Choosing the OEM-specified plug means cleaner ignition, better fuel economy, and fewer surprises when you least want them. It’s simply the smarter play — the kind of advice you’d give a friend at the dock before a long weekend run.

FAQ

Q1: Which engines does this plug fit?

Any Mercury engine that specifies NGK IZFR5G in the owner’s manual.

Q2: Why choose this OEM spark plug instead of aftermarket?

It meets Mercury’s ignition and heat-range requirements, offering better stability and lifespan.

Q3: How can I confirm it’s correct for my setup?

Check your manual — if it lists part number 889597Q or NGK IZFR5G, this is the one.

Q4: Can it be used in saltwater and freshwater?

Absolutely — it’s built to resist corrosion and withstand marine heat cycles.

Q5: Is installation straightforward?

Yes, most boat owners can install it with a standard spark plug socket.