Marinepro Outboard Water Pump Impeller Kit for Mercury/Mariner 8–25 HP — Complete Housing, Impeller & Seal Set

This kit supplies the key components needed during a routine water-pump service or emergency repair. It replaces several Mercury part numbers and GLM references and covers a broad range of 2-stroke and 4-stroke outboards across 8–25 horsepower, including specific BigFoot 9.9 hp and 15 hp 4-stroke serial ranges. The kit groups the housing, impeller, seals and mounting parts so you can install a fresh, sealed pump with minimal downtime.

Which Mercury and Mariner engines will this kit fit?

The kit is built to match OEM fitment for many Mercury and Mariner outboards in the 8–25 HP range. It lists multiple legacy part numbers it replaces, making it suitable for common service needs across model years. Verify compatibility by checking your engine's horsepower and serial number ranges for the BigFoot models.

• Covers 2-stroke 15, 18, 20, 25 HP and 4-stroke 8, 9.9, 13.5, 15 HP engines.
• Fits BigFoot 9.9 HP (323cc) and 15 HP (323cc) 4-stroke within specified serial ranges.
• Direct replacement for Mercury numbers including 46-99157T2 and related part variants.

What parts are included and why each one matters?

This kit bundles every component needed to rebuild the water pump assembly rather than buying items separately. That reduces compatibility risk and ensures you have the right gaskets and seals to prevent leaks. Having the drive key, washers, grommets and rings on hand simplifies reassembly and improves the long-term reliability of the pump.

• Pump housing assembly and face plate — foundation for correct alignment and sealing.
• Impeller — the elastomer rotor that moves cooling water through the engine.
• Gasket and seal — prevent external leaks and maintain internal water pressure.
• Drive key, washers, grommets, and rings — small parts that secure and center the rotating assembly.

How easy is installation for a DIY mechanic or technician?

Installation is straightforward for anyone comfortable with basic outboard service, though access and engine configuration can affect difficulty. The kit replaces the old impeller and associated hardware in one service session; you should follow a service manual or step-by-step guide for torque specs and alignment. If rusted fasteners or seized components are present, allow extra time or consult a technician.

• Complete hardware set reduces trips to the parts counter mid-job.
• No special tools beyond common marine hand tools and torque wrench for reassembly.
• Recommended to inspect housing bore and water passages before installing new parts.

Who is this for? Boaters, marine technicians, and DIY mechanics who maintain Mercury or Mariner outboards in the 8–25 HP range will find this kit useful. It’s especially beneficial for owners of older engines that need OEM-equivalent replacements, and for anyone who wants a ready-to-install service kit that includes small parts often lost during disassembly. Always confirm engine serial numbers and horsepower before ordering to ensure fitment.