Sea Water Pump Impeller Repair Kit – Fits MerCruiser 4.5L & 6.2L Engines

Sea Water Pump Impeller Repair Kit – Fits MerCruiser 4.5L & 6.2L Engines

This heavy-duty sea water pump impeller repair kit is designed for Mercury MerCruiser 4.5L V6 and 6.2L V8 sterndrive and inboard engines from 2014 and newer (serial numbers 2A531163 and above).

It serves as a direct replacement for Mercury/Quicksilver part numbers 8M0137221, 8M0121940, and 8M0137220, as well as GLM Marine parts 89703 and 89704.

• Engineered with a high-flow design to improve cooling efficiency.
• Facilitates direct replacement into the sea water pump assembly.
• Includes all necessary components for a complete impeller service.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Water Pump Impeller
• 2 x Wear Plates (1 x Rear wear plate, 1 x Overmolded inner/front wear plate)

Installation Guide

1. Disconnect the negative battery cable.
2. Close the engine's seacock to prevent water from entering the hull.
3. Locate the sea water pump and place a rag or container underneath to catch any spilled coolant.
4. Remove the bolts securing the pump’s end cover.
5. Carefully pry off the cover. Note the orientation of the old impeller vanes if possible.
6. Remove the old impeller and wear plates from the housing.
7. Clean the interior of the pump housing and cover, removing any old gasket material or debris.
8. Install the new rear wear plate into the housing.
9. Lubricate the new impeller and the inside of the housing with a suitable marine lubricant.
10. Install the new impeller by pushing and turning it in the direction of engine rotation to bend the vanes correctly.
11. Place the new overmolded front wear plate onto the housing and secure it with the cover and bolts, tightening them to the manufacturer's specified torque.
12. Open the seacock, reconnect the battery, start the engine, and immediately check for proper water flow and any signs of leaks.

Troubleshooting & FAQ

Q: How do I confirm this fits my MerCruiser engine?

A: This kit is specifically for MerCruiser 4.5L V6 and 6.2L V8 engines manufactured in 2014 or newer. The most reliable way to confirm fitment is to check if your engine's serial number is 2A531163 or higher. You can also cross-reference your current part number with the OEM numbers this kit replaces, such as 8M0137221.

Q: What are the signs my sea water pump impeller is failing?

A: Common symptoms include your engine running hotter than normal, especially at idle or low speeds; a weak or inconsistent stream of water from the exhaust outlet; or, upon inspection, discovering the impeller has brittle, cracked, or missing vanes.

Q: How often should I replace the impeller?

A: As a crucial part of preventative maintenance, it is recommended to inspect the impeller annually. Replacement is advised every 1 to 2 years, though this can vary based on operating hours and conditions (e.g., frequent use in saltwater or sandy/silty water may require more frequent changes).

Q: OEM vs. Aftermarket?

A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?

A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?

A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.