Mercury – Quicksilver 812966A12 Water Pump Repair Kit | Mercury & Mariner 4-Stroke 30–60HP Outboards | Complete OEM Kit | 812966A12

Overview

Every seasoned boater knows how critical a reliable water pump is. It’s the part that quietly keeps your engine cool, trip after trip. The Quicksilver 812966A12 Water Pump Repair Kit gives your Mercury or Mariner 4-stroke outboard (30–60HP) a full refresh, restoring proper water flow and cooling performance.

This kit isn’t just a quick fix — it’s one of the most complete OEM kits available, with everything you need to bring your pump back to factory condition. Whether you’re doing routine maintenance or replacing a worn impeller after years of service, this set ensures your motor stays protected and running cool in every condition.

Key Features

• Purpose: Restores full cooling performance by replacing key water pump components.
• Fitment: Designed for Mercury and Mariner 4-stroke EFI and carbureted outboards, 30–60 horsepower.
• Kit Contents: Includes impeller, upper and lower housings, face plate, gaskets, drive key, face seal, seal carrier, and water tube coupling.
• Build Quality: All parts meet Mercury Marine OEM standards, ensuring a perfect fit and long-lasting durability.
• Ease of Service: Everything is included for a full rebuild using standard shop tools — no extra parts to chase down.

Engine & Boat Compatibility

• Mercury and Mariner 4-stroke 30–60HP outboards (EFI and carbureted models)
• Found on small cruisers, fishing rigs, pontoons, and utility boats

Performance & Practical Benefits

Your outboard’s water pump does the heavy lifting of keeping your engine cool. When the impeller or seals wear out, water flow drops, and overheating isn’t far behind. The 812966A12 kit replaces every critical piece — not just the impeller — restoring full pressure and flow throughout the cooling system.

With new housings, seals, and gaskets, you’ll get peace of mind knowing the system is tight and efficient. The pump will prime quickly, circulate water properly, and prevent overheating even during long runs at wide-open throttle. It’s the kind of maintenance that pays for itself in reliability and engine life.

Why Buy OEM

Mercury OEM components are engineered specifically for the demands of marine cooling systems. The materials are built to handle constant exposure to water, heat, and vibration — things aftermarket parts often can’t replicate.

An OEM kit guarantees proper clearances, exact seal fitment, and impeller flexibility that matches your engine’s original design. Aftermarket kits can be hit or miss, sometimes including parts that don’t align correctly or wear out too soon. With genuine Quicksilver parts, you’re not just replacing — you’re restoring.

FAQ

Q1: Which engines use the Quicksilver 812966A12 kit?
A: It fits Mercury and Mariner 4-stroke outboards (30–60HP), both EFI and carbureted versions.

Q2: What’s included in the kit?
A: Everything you need for a full rebuild: impeller, upper and lower housings, face plate, gaskets, drive key, face seal, seal carrier, and water tube coupling.

Q3: How often should I replace the water pump?
A: Mercury recommends inspecting the impeller annually and replacing the full pump every 2–3 years or sooner in sandy or muddy conditions.

Q4: Can I install it myself?
A: Yes. Anyone with basic mechanical skill and standard tools can complete the replacement by following the service manual.

Q5: Why not use an aftermarket kit?
A: Aftermarket kits can use cheaper rubber compounds or misaligned housings, leading to poor flow or premature wear. OEM parts fit right and last longer.