Mercury – Distributor Assembly | Ignition System | High-Strength Polymer & Marine Alloys | 879150A87

Overview

Anyone who’s spent years running MerCruiser engines knows how much the ignition system shapes the way the boat feels on the water. When the spark is right, the engine wakes up with a smooth, eager note that pulls cleanly through every throttle position. This Mercury Marine distributor assembly brings that feeling back. It’s built for boaters who want their engine to run steady, clean, and predictable—no sputtering, no hesitation, just confident ignition every time you advance the throttle. Installing this part feels like restoring the heart of the engine itself.

Key Features

• Complete distributor housing assembly engineered for precision ignition timing.
• Durable PBT and PET polymer blend cap for increased strength and thermal resistance.
• Marine-grade internals designed to withstand heat, moisture, and vibration.
• Built to Mercury’s strict OEM tolerances for long-lasting performance.
• High strength-to-weight ratio reduces stress and prevents cracking or warping.

Engine & Boat Compatibility

• Fits MerCruiser 5.0 liter, 5.7 liter, and 6.2 liter sterndrive and inboard engines.
• Designed for models using the ECM 555 ignition system (serial numbers 0M300000–2A460164).
• Ideal for cruisers, runabouts, tow boats, sport boats, and classic sterndrive setups.

Performance & Practical Benefits

A fresh distributor transforms the way these engines behave. You’ll notice immediate improvements in throttle response, idle consistency, and acceleration. The spark becomes steadier, letting the engine breathe and burn fuel more efficiently. That tight, smooth feeling at mid-range cruising speeds becomes easier to maintain. The high-strength polymer cap resists heat and vibration, eliminating the micro-cracks that often cause irregular spark or moisture intrusion in older distributors. Once installed, the engine feels more predictable, less prone to misfires, and better at holding a steady RPM in rougher water.

Why Buy OEM

Ignition components are not the place to gamble with aftermarket tolerances. On these engines, timing, alignment, and internal spacing matter down to the millimeter. Mercury Marine’s distributor assemblies are built to match the original ignition engineering exactly. Aftermarket caps and housings often warp, misalign, or rely on cheaper metals that fail under heat. With OEM, you get a part designed for the vibration profile, load cycles, and electrical demands of these specific MerCruiser engines. It’s a smarter choice that helps protect the engine long-term.

FAQ

Q1: Which engines does this distributor fit?

MerCruiser 5.0L, 5.7L, and 6.2L engines using the ECM 555 ignition system.

Q2: Why choose OEM for ignition parts?

You get precise spark timing, better durability, and protection against misfires and early component failure.

Q3: How do I confirm fitment?

Check your engine’s serial number and make sure it falls within the listed ECM 555 range.

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

Yes—its marine-grade design is built for either environment.

Q5: Installation difficulty?

 With basic mechanical experience and your manual, installation is straightforward.