Mercury – Water Pump Assembly | V6 & V8 Sterndrive Cooling | OEM Housing & Components | 8M0113734

Overview

Anyone who’s spent long days running a MerCruiser engine knows how much trust you place in your cooling system. When the water pump is healthy, the boat feels different — the engine settles into a steady hum, the throttle feels smoother, and you stop thinking about temperature gauges altogether. That’s the kind of quiet confidence the Mercury 8M0113734 Water Pump delivers. For V6 and V8 sterndrive owners, it’s one of those essential components that keeps your engine protected so the only thing you’re focused on is the water ahead.

Key Features

• Complete replacement water pump and housing
• Built for select V6 MerCruiser engines (serial No. 1A0632239 and below)
• Fits V8 MerCruiser engines including 305, 350, and 377 cubic inch displacement models
• Includes gaskets for a proper, leak-free installation
• Designed to meet Mercury Marine’s original equipment specifications

Engine & Boat Compatibility

• Compatible with General Motors–based V6 MerCruiser sterndrive engines
• Fits V8 MerCruiser 305, 350, and 377 sterndrive engines
• Common on bowriders, small cruisers, sport boats, deck boats, and performance sterndrive setups
• Ideal for engines used in warm climates, high-load operation, or extended cruising

Performance & Practical Benefits

A reliable water pump is the heartbeat of your engine’s cooling system. Install this assembly, and you’ll notice the engine temperature holding steady in every condition — long idle periods at the marina, slow trolling passes, or high-speed runs across the lake. The housing and impeller work together to provide strong, consistent water flow, keeping the engine from overheating and protecting internal components from stress and premature wear.

The parts fit together with the satisfying precision you expect from an OEM design. The gaskets seal tight, the housing aligns without fuss, and everything locks in with a secure, steady feel. On the water, that translates into smoother operation, a more predictable temperature curve, and better long-term durability. The materials resist corrosion and heat stress, giving you season after season of dependable service. For many boaters, replacing the water pump is a smart, preventative move — one that saves you from costly repairs and engine downtime later.

Why Buy OEM

Water pumps aren’t a place to cut corners. Aftermarket versions may look similar, but small differences in impeller design, housing tolerances, or gasket quality can cause reduced flow or early failure. Mercury Marine part number 8M0113734 is engineered specifically for these V6 and V8 sterndrives, ensuring correct flow rates and long-term protection. You’re choosing a part that fits right, performs right, and holds up to the demands of real boating. For reliability and peace of mind, OEM is simply the practical choice.

FAQ

Q1: Which engines does the Mercury 8M0113734 Water Pump fit?

It fits select V6 MerCruiser engines (serial No. 1A0632239 and below) and V8 models with 305, 350, or 377 cubic inch displacement.

Q2: How is this different from aftermarket pumps?

OEM pumps match factory specifications exactly, ensuring consistent cooling flow and long-term durability.

Q3: How can I confirm this is the correct part?

Check your engine serial number or refer to your service manual for part number 8M0113734.

Q4: Can it be used in saltwater and freshwater?

Yes — the materials are designed to withstand both environments.

Q5: Is installation straightforward?

Most boat owners comfortable with basic engine service can install it using common shop tools.