Mercury – Sea Pump Kit | Cooling System Component | Marine-Grade Construction | 8M0139996

Overview

Most of us who spend real time on the water know that engine cooling is one of those things you rarely think about—until the moment you have to. That is why having a dependable, factory-built sea pump gives such a sense of calm. The Mercury 8M0139996 Sea Pump Kit delivers that quiet reassurance every boater wants, especially when you are running through choppy inlets or easing away from a crowded marina with the sun dropping behind you. Designed for MerCruiser MPI engines equipped with an air-actuated drain system, this pump keeps coolant flowing steady and strong so the engine stays relaxed, responsive, and protected. It is the kind of part that earns trust mile after mile.

Key Features

• Fully assembled sea pump designed for select MerCruiser MPI engines
• Marine-grade construction for corrosion resistance in harsh saltwater use
• Engineered to meet or exceed Mercury Marine OEM specifications
• Built for consistent cooling flow and long service life
• Ideal replacement to restore proper engine cooling performance
• Designed to handle abrasive conditions common in coastal boating
• Drop-in design for straightforward installation

Engine & Boat Compatibility

• Fits MerCruiser 4.3L, 5.0L, 5.7L, 6.2L, and 8.2L MPI engines with air-actuated drain systems
• Not compatible with MerCruiser 6.2L MPI engines serial number 2A456613 and higher
• Suitable for sport boats, cruisers, runabouts, and inboard tow boats
• Works in both saltwater and freshwater environments
• Designed for inboard and sterndrive cooling systems requiring a sea pump assembly

Performance & Practical Benefits

A cooling pump has one job, but it is a job your whole day depends on. This OEM pump is built to deliver steady, tight, reliable water flow that keeps engine temperatures right where they should be. On the water, you will feel the difference—smoother running, a steadier idle, and that clean, confident throttle response you expect from a well-maintained MerCruiser.

The pump arrives fully assembled, which takes a lot of the frustration out of the job. You will notice the precise fit right away, and the robust housing and internal components are engineered to stand up to saltwater, sand, and the general abuse that comes with real boating. Once installed, the cooling system settles into a secure, consistent rhythm, giving you one less thing to worry about while the boat is under load.

Long days offshore, lazy afternoons towing the kids, or early-morning runs to a fishing spot—this pump keeps your engine cool through all of it. That reliability builds confidence over time, and that confidence is worth more than just a replacement part.

Why Buy OEM

When it comes to a component as important as the cooling pump, the smart move is the OEM one. Mercury Marine builds parts that match the exact tolerances, materials, and flow rates your engine was designed around. Aftermarket options often fall short, and the risk of overheating or premature wear just is not worth the gamble. With the 8M0139996 kit, you are getting lasting durability, proper cooling performance, and a part that fits right the first time—saving time, saving money, and keeping you on the water instead of troubleshooting at the dock.

FAQ

Q1: Which Mercury engines does the 8M0139996 Sea Pump Kit fit?

It fits MerCruiser 4.3L, 5.0L, 5.7L, 6.2L, and 8.2L MPI engines with an air-actuated drain system, except newer 6.2L MPI engines above serial number 2A456613.

Q2: What makes this pump different from aftermarket versions?

It meets full OEM specifications, offering better longevity, better cooling flow, and a more precise fit.

Q3: How do I confirm compatibility?

Match your engine model and serial number with the notes in your owner’s manual.

Q4: Can this pump be used in saltwater and freshwater?

Yes, it is built to thrive in both, including highly corrosive coastal environments.

Q5: Is installation straightforward?

Yes. Since it is fully assembled, most boat owners with basic mechanical experience can install it confidently.