Mercury – Quicksilver Water Pump Base Assembly | Cooling System Part | Reinforced Nylon | 48748A1

Overview

If your MerCruiser is running hotter than normal or losing water pressure, the problem might start at the pump base. The Mercury Marine 48748A1 Quicksilver Water Pump Base Assembly gives your cooling system a solid foundation, keeping the impeller aligned and water flowing smoothly. Designed for MerCruiser 120, 140, and 160 sterndrives with flush screw-in gear housings, it’s made from reinforced nylon that won’t crack or deform under heat and pressure. It’s a tough, long-lasting part that helps your engine stay cool and dependable year after year.

Key Features

• Job: Supports the impeller and seals the lower unit to maintain even water flow.
• Material: Made from reinforced nylon, resistant to heat, vibration, and saltwater corrosion.
• Design: Built to factory Mercury dimensions for a precise fit.
• Performance: Keeps the impeller stable, ensuring consistent pressure and cooling.
• Durability: Lightweight but tough enough to handle long-term marine use.
• Fit: Designed for MerCruiser 120, 140, and 160 sterndrives with screw-in gear housings.

Engine & Boat Compatibility

• MerCruiser 120 sterndrives (flush screw-in gear housing)
• MerCruiser 140 sterndrives (flush screw-in gear housing)
• MerCruiser 160 sterndrives (flush screw-in gear housing)

Performance & Real-World Benefits

The 48748A1 pump base keeps your cooling system steady by securing the impeller and sealing the pump chamber. That means steady water pressure, cooler running temperatures, and fewer overheating headaches. The reinforced nylon construction holds up against constant water flow and vibration, resisting wear that can lead to leaks or weak circulation.

If your pump base is old or cracked, it can cause air leaks that disrupt water flow. Replacing it restores smooth, reliable cooling performance — and helps your engine stay protected on long runs or hot summer days.

Why Choose Mercury OEM

The Quicksilver 48748A1 is a genuine Mercury Marine replacement part, built to match your engine’s exact specs. Aftermarket parts might look the same but often don’t line up perfectly or use materials that soften under heat.

Mercury’s OEM parts are tested under real boating conditions for durability and precision. With OEM, you get a part that fits right the first time and keeps your cooling system working exactly as it should.

FAQ

Q1: What drives does this base fit?
It fits MerCruiser 120, 140, and 160 sterndrives with flush screw-in gear housings.

Q2: What’s it made from?
It’s made from reinforced nylon, a strong, corrosion-resistant material designed for marine use.

Q3: Why replace it?
Cracked or warped bases can cause leaks and reduced water flow, leading to overheating.

Q4: Can I install it myself?
Yes — it installs easily with basic tools when servicing your impeller or lower unit.

Q5: Why OEM instead of aftermarket?
OEM ensures the right dimensions, sealing surfaces, and durability tested by Mercury engineers.