Mercury – Water Pump Impeller for FourStroke 8–20 Horsepower Outboards | Cooling System Component | Black Marine Elastomer | 8M0214944

Overview

If you spend enough time on the water, you learn to trust the parts that keep your engine cool and steady. A good water pump impeller is one of those unsung heroes — the kind of piece you rarely see but always rely on. When it’s working right, you feel it in the way the engine settles into a smooth rhythm, even after hours of exploring coves or drifting along a shoreline. This Mercury Marine part brings that familiar confidence. Slip it in during your seasonal service, and you’ll know the motor is ready to handle both long weekends and quick morning runs without breaking a sweat.

Key Features

• Designed to deliver a consistent flow of cooling water to Mercury FourStroke outboards
• Constructed from high-quality marine elastomers for flexibility and long-term durability
• Black elastomer finish maintains shape across broad temperature swings
• Produces strong flow rates to protect the engine at idle, cruise and wide-open throttle
• Meets Mercury Marine original equipment manufacturing standards for cooling performance
• For use on:
  • Eight and nine point nine horsepower FourStroke outboards (serial 0R042475 and up)
  • Twenty horsepower FourStroke outboards (serial 0R235168 and up)
• Mercury Marine part number 8M0214944 / Quicksilver 803748

Engine & Boat Compatibility

• Fits Mercury FourStroke eight to nine point nine horsepower models
• Fits Mercury FourStroke twenty horsepower models
• Common on jon boats, inflatables, dinghies, small fishing rigs and lightweight tenders
• A great match for portable family runabouts and small utility boats that rely on steady cooling to stay efficient

Performance & Practical Benefits

A strong cooling system can make the difference between a relaxed afternoon on the lake and a trip cut short by overheating. This impeller keeps the water moving with a steady, reliable pull. You’ll feel it in the way your outboard holds temperature on long upstream runs or during slow, careful trips through shallows. The elastomers flex smoothly, keeping the blades tight against the pump housing for consistent flow. Even after plenty of hours on the water, the material resists cracking and stiffening — problems that cheaper aftermarket parts struggle with. That means less worry, fewer surprises and a motor that starts and runs the way you expect every time. Seasonal maintenance becomes easier too, since the impeller installs cleanly and seats without drama.

Why Buy OEM

There’s no shortcut when it comes to keeping an engine cool, and that’s why sticking with a genuine Mercury Marine part makes sense. OEM cooling components are engineered to match the exact tolerances of your outboard’s water pump, ensuring the blades contact the housing correctly and deliver the flow your engine needs. Aftermarket pieces might work for a while, but they often fall short when pushed through temperature swings, long days or silt-heavy shallows. With OEM, you’re paying for reliability and the reassurance that your outboard won’t surprise you when you’re miles from the dock. It’s the practical, real-world choice for boaters who value dependability over guesswork.

FAQ

Q1: Which engines does the Water Pump Impeller 8M0214944 fit?

It fits Mercury FourStroke eight to nine point nine horsepower outboards and twenty horsepower FourStroke engines within the listed serial ranges.

Q2: What makes this impeller different from aftermarket options?

The materials and tolerances are engineered specifically for Mercury cooling systems, giving you better flow and longer life.

Q3: How do I know if this is the right replacement?

Check your serial number and horsepower range. If it matches the compatibility listed above, this is the correct Mercury Marine part.

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

Yes — the elastomer design handles both environments well and resists long-term wear.

Q5: Is installation straightforward?

Most boat owners with basic maintenance experience can replace it during routine service. It fits cleanly and seats securely.