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FLASHSALE26

Water Pump Repair Kit with Housing – Fits Mercury/Mariner 2-Stroke 15–25 HP & 4-Stroke 9.9–15 HP

Regular price $42.50

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Delivery and Shipping

Orders are typically processed within 1–2 business days.


U.S. orders usually arrive within 6–15 days, depending on stock location and destination.


International delivery times may vary due to customs processing.


Tracking information will be provided once your order ships.

If you have any questions, feel free to email us at info@seasierra.com, and we’ll get back to you within 20–36 hours.

Product Details

This water pump repair kit with pump housing is designed to service the upper water pump assembly on selected Mercury and Mariner outboard engines. It covers listed 2-stroke applications including 15XD, 18, 18XD, 20XD, 25XD, Sea Pro, Marathon, and Super 15 models, plus listed 4-stroke 9.9 HP and 15 HP Bigfoot models with 323 cc engines.

The kit is an aftermarket replacement for the Mercury/Mariner water pump references listed below. Always compare the original pump, engine model, and serial number before ordering.

  • Upper water pump service kit supplied with pump housing.
  • Designed for selected Mercury and Mariner outboard applications.
  • Includes a neoprene marine impeller and replacement sealing components.
  • Stainless-steel pump housing for corrosion-resistant marine service.

Part Number Matrix

Use these manufacturer and aftermarket references to compare the kit with your existing water pump components.

Brand Reference Reference type
Mercury/Mariner 46-99157T2 OEM reference
Mercury/Mariner 46-99157A02 OEM reference
Mercury/Mariner 46-99157A2 OEM reference
Mercury/Mariner 46-85098A2 OEM reference
Mercury/Mariner 85098A2 OEM reference
Mercury/Mariner 99157A2 OEM reference
Mercury/Mariner 99157T2 OEM reference
GLM Marine 12014 Aftermarket reference

Engine & Model Compatibility

Fitment depends on the complete engine model and serial-number range. The following applications are listed for this pump kit; confirm the original part and serial number before installation.

Brand Model or application Rated HP Stroke Serial or application notes
Mercury/Mariner 15XD / Bigfoot 15 2-Stroke Confirm the engine serial number.
Mercury/Mariner 18 / 18XD 18 2-Stroke Confirm the engine serial number.
Mercury/Mariner 20XD 20 2-Stroke Confirm the engine serial number.
Mercury/Mariner 25XD 25 2-Stroke Confirm the engine serial number.
Mercury/Mariner Sea Pro / Marathon / Super 15 15–25 2-Stroke Confirm the exact model and serial number.
Mercury/Mariner 3-cylinder application listed in the company catalog 50 2-Stroke Verify the original pump and serial number carefully before ordering.
Mercury/Mariner 9.9 Bigfoot, 323 cc 9.9 4-Stroke Confirm the engine serial number.
Mercury/Mariner 15 Bigfoot, 323 cc 15 4-Stroke Confirm the engine serial number.

Technical Specs

Product Type
Water pump repair kit with pump housing
Installation
Upper water pump assembly
Housing Material
Stainless steel
Impeller Material
Neoprene marine rubber
Gasket Material
Non-asbestos
Product Status
Aftermarket replacement, not an OEM-manufactured component

What’s in the Box

The kit is supplied with the pump housing and the service components needed for the listed water pump applications.

  • 1 x Pump housing assembly
  • 1 x Neoprene impeller
  • 1 x Face plate
  • 1 x Gasket
  • 1 x Impeller key
  • 1 x Seal
  • 2 x Washers
  • 4 x Insulators
  • 3 x O-rings
  • 1 x Water tube guide sleeve

Component appearance may vary slightly from the original parts. Compare the supplied components with the removed parts before installation.

Installation Notes

  1. Disconnect the battery and remove the engine cover.
  2. Support the engine securely and remove the lower unit according to the engine service procedure.
  3. Remove the water pump housing from the top of the gearcase.
  4. Remove the old impeller, key, face plate, gaskets, seals, and related service parts.
  5. Clean the mating surfaces and inspect the driveshaft, water tube, and pump plate for wear or damage.
  6. Install the new gasket, face plate, impeller, key, seals, and housing. Ensure the impeller key is correctly seated.
  7. Use a marine-safe lubricant where appropriate and tighten fasteners to the engine manufacturer’s specifications.
  8. Reinstall the lower unit, carefully aligning the driveshaft and water tube.
  9. Test the engine in a suitable water supply and confirm a steady cooling-water tell-tale stream before normal operation.

Professional installation is recommended when removing or reinstalling the lower unit.

Troubleshooting & FAQ

How do I confirm this kit fits my engine?

Match the engine brand, exact model, horsepower, stroke, and serial number with the compatibility information. Also compare the original pump housing, impeller, and mounting arrangement with the kit before purchase.

What are common signs of a failing water pump?

Common symptoms include overheating at idle or low speed, a weak or intermittent tell-tale stream, and reduced cooling-water flow. A blocked intake, thermostat problem, or damaged water tube can produce similar symptoms.

When should the impeller be replaced?

Inspect the impeller regularly and replace it when the blades are damaged, hardened, permanently set, or showing signs of wear. Sandy or saltwater operation may require more frequent inspection.

Can I install the kit myself?

Installation is possible for an experienced marine technician or mechanic, but the lower unit is heavy and must be aligned correctly. Follow the engine service manual and use the specified torque values.

What if the engine still overheats after installation?

Check the water-intake screens, water tube alignment, thermostat, internal cooling passages, pump plate, and tell-tale passage. Confirm that the impeller key and impeller rotation are installed correctly.

Is this an OEM part?

No. This is an aftermarket replacement kit intended to service the listed Mercury and Mariner water pump applications. Mercury and Mariner are manufacturer trademarks used only to identify compatibility.

Safety & Important Information

  • Verify the exact engine model, stroke, horsepower, and serial number before ordering.
  • Do not operate an outboard with insufficient cooling-water flow or signs of overheating.
  • Inspect all mating surfaces and related cooling-system components during installation.
  • This aftermarket kit is not manufactured by Mercury or Mariner.

About Sea Sierra

  • Marine Replacement Parts — We supply aftermarket service parts for common outboard maintenance and repair applications.
  • Application-Focused Listings — Product information is organized around engine model, horsepower, stroke, serial range, and replacement references.
  • Service Support — Compare the original component and consult a qualified marine technician whenever fitment or installation is uncertain.

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