Mercury – Water Pump Upper Repair Kit | EFI FourStroke Cooling System | Marine-Grade Service Kit | 8M0094529

Overview

A healthy cooling system is one of those things you don’t brag about—you just quietly depend on it. When you’re trimmed out and cruising, the last thing you want in the back of your mind is temperature creeping up or a weak telltale stream. Outboards are happiest when the cooling system is tight, sealed, and moving water the way it should, every single trip.

This Mercury Marine part is for the boater who’d rather handle maintenance on their own terms than get surprised mid-season. The Water Pump Upper Repair Kit helps you bring that steady, confident feeling back—like your engine is breathing easy again. You service it once, and then you get to enjoy the ride without watching gauges like a hawk.

Key Features

• Service kit designed to repair and refresh the outboard water pump and cooling system
• Supports reliable water flow to help maintain stable operating temperature
• Includes key components for a thorough repair:
  • Upper and lower pump housing
  • Plate
  • Gaskets and seals
  • Key
  • Impeller
• Built as one of the most complete kits available for outboard water pump repair
• Designed for select Mercury and Mariner EFI FourStroke outboards
• Mercury Marine part number 8M0094529

Engine & Boat Compatibility

• Mercury or Mariner 75 horsepower to 115 horsepower EFI FourStroke outboards (serial number 2B094996 and up)
• Mercury or Mariner 150 horsepower EFI FourStroke outboards (serial number 1B905505 and up)
• Common on bay boats, bass boats, pontoons, family runabouts, and utility fishing rigs

Performance & Practical Benefits

Water pump service is one of those maintenance jobs that pays you back immediately. When the pump is fresh and properly sealed, the engine feels more dependable—because it is. You’ll usually notice a stronger, more consistent telltale stream and less “nagging doubt” when you’re running a long stretch or idling through a hot marina channel.

What makes this kit so useful is how complete it is. Instead of replacing one piece and hoping the rest holds, you’re renewing the core wear items that affect how the pump seals and flows. New housings, plate, gaskets, and seals help everything sit tight and aligned. The impeller, of course, is the heart of it—when it’s fresh, water movement feels steady and confident again, especially at idle where weak pumps love to show their age.

Installation is also more straightforward when the parts are made to match. The fitment tends to feel clean and secure, which matters in a system where tiny gaps can turn into leaks, loss of prime, or reduced cooling efficiency. Service it with care, and you’re setting yourself up for simpler boating—less troubleshooting, fewer surprises, and more time doing what you came for.

Why Buy OEM

Cooling system parts are not where I recommend rolling the dice. A genuine Mercury Marine part is designed around the exact pump dimensions and sealing surfaces your outboard needs. That means fewer fitment headaches, better long-term reliability, and a cooling system that performs the way Mercury intended.

Aftermarket kits can vary in materials and tolerances, and with water pumps, “almost right” can still lead to problems. OEM is the practical choice: it’s built to fit right the first time, last longer, and help keep your engine protected season after season.

FAQ Section

Q1: Which Mercury engines or systems does the Water Pump Upper Repair Kit fit?

It fits select Mercury and Mariner 75 horsepower to 115 horsepower EFI FourStroke outboards (serial number 2B094996 and up) and 150 horsepower EFI FourStroke outboards (serial number 1B905505 and up).

Q2: What makes this part different from aftermarket alternatives?

It’s a Mercury Marine part built for correct fitment and includes a very complete set of components for a proper pump repair, not a partial refresh.

Q3: How do I know if this is the correct replacement for my setup?

Confirm your horsepower, EFI FourStroke model, and serial number range, then match the part number to 8M0094529.

Q4: Can this be used in both saltwater and freshwater applications?

Yes. Water pump components serve the cooling system in either environment. Regular flushing and inspection are especially important in saltwater.

Q5: Is installation straightforward for most boat owners?

Many experienced boat owners handle water pump service themselves with basic tools and a service manual. If you’re not comfortable, a marine technician can install it quickly.