Mercury – Water Pump Repair Kit, 3.3HP | Cooling System | 8M0080264

Overview

These little 3.3HP Mercury and Mariner outboards are simple motors, but they don’t give you much warning when the water pump starts getting tired. A weak pee stream, the engine running warmer than it should, or a bit of steam at idle usually means the impeller isn’t moving water the way it used to. This kit gives you everything to rebuild the pump the right way—impeller, gaskets, o-ring, plates, the key, and the hardware most folks drop in the grass at least once. It’s a small job that makes a big difference in how these small engines stay alive.

Key Features

 • Full Pump Kit – Impeller, plates, gaskets, o-ring, key, and hardware included.
 • Made for 3.3HP Mercury & Mariner Models – Fits the F-N-R versions of these portable outboards.
 • Restores Cooling Flow – Helps bring back a strong telltale and steadier temps.
 • Flexible Impeller Material – Works well across cold mornings and hot summer water.
 • OEM-Tuned Fitment – Matches Mercury’s clearances so the pump builds proper pressure.

Engine & Boat Compatibility

 • Mercury 3.3HP
 • Mariner 3.3HP
 • F–N–R small outboards
 • Dinghies, inflatables, tenders, jon boats

Performance & Practical Benefits

Once you rebuild the pump on these little motors, you usually notice the improvement right away. The telltale stops sputtering, the engine cools more evenly, and it feels safer idling through shallows or putting around the marina. These outboards don’t have much cooling margin, so a good impeller and clean pump base keep them from overheating on long runs or hot days.

Why Buy OEM

Small outboards rely heavily on tight pump clearances. OEM parts fit right, seal right, and use the rubber compounds Mercury designed the pump around. Aftermarket impellers can be too stiff, too soft, or slightly off in size—any of which can hurt flow or burn up the impeller early. OEM keeps everything predictable.

FAQ

Q1: What signs tell me the pump needs a rebuild?
A: Weak water stream, hotter-than-normal running, or steam when idling.

Q2: Should I replace the impeller every season?
A: Many boaters do—especially if they run shallow or sandy water.

Q3: Is this a job I can tackle myself?
A: Yes. Dropping the lower unit on a 3.3HP is one of the easier pump jobs out there.

Q4: What’s the risk of ignoring a bad impeller?
A: Overheating, scoring the cylinder, or even seizing the engine.

Q5: Does the kit include everything I need?
A: Yes—impeller, plates, gaskets, o-ring, key, and hardware are all in the box.