Water Pump Impeller Kit – Fits Mercury/Mariner 3.9-9.8 HP (Replaces 46-92970A5, 47-89980Q1)

Water Pump Impeller Kit – Fits Mercury/Mariner 3.9-9.8 HP (Replaces 46-92970A5, 47-89980Q1)

This water pump impeller kit is designed for Mercury/Mariner 2-Stroke outboards (3.9, 4, 4.5, 6, 7.5, and 9.8 HP) from 1975–1986 requiring a 0.438" shaft diameter.

It serves as a direct replacement for multiple OEM and aftermarket part numbers, ensuring a precise fit and restoring cooling system performance. This kit provides all essential components for a complete water pump service.

• Installation Method: Direct Replacement
• Key Component: Includes impeller and all necessary gaskets for a complete service.
• Compatibility: Specifically fits models with a 0.438 inch (11.13 mm) impeller shaft.

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 Impeller
• 1 x Set of Gaskets & Seals

Installation Guide

1. Disconnect the spark plug wires and shift the outboard into neutral.
2. Locate and remove the bolts securing the lower unit (gearcase) to the upper leg.
3. Carefully lower and separate the gearcase from the outboard's driveshaft housing.
4. Unbolt and remove the water pump housing cover to expose the old impeller.
5. Note the rotational direction of the old impeller fins before removal.
6. Remove the old impeller, gaskets, wear plate, and seals from the housing.
7. Thoroughly clean all mating surfaces, removing any old gasket residue or corrosion.
8. Install the new gaskets, wear plate, and seals included in the kit.
9. Slide the new impeller onto the driveshaft, turning the shaft in its normal operating direction to bend the fins correctly.
10. Reinstall the water pump housing and tighten the bolts to the manufacturer's specified torque.
11. Reattach the lower unit to the outboard, ensuring the driveshaft, shift shaft, and water tube align properly.
12. Once assembled, test the engine using a water supply to confirm a strong and steady stream from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this impeller kit fits my specific engine?
First, check the compatibility table on this page. Ensure your engine's make, model, HP, and year range are listed. The most critical specification is the impeller shaft diameter of 0.438 inches, as this is a key identifier for this series. Cross-referencing your old part number with the numbers listed (e.g., 46-92970A5, 47-89980Q1) is the best way to guarantee a match.

What are the common symptoms of a failing water pump impeller?
The most common signs are a weak or non-existent water stream from the "tell-tale" outlet and an overheating engine alarm. A visual inspection of the old impeller may reveal cracked, brittle, or broken fins.

How often should I replace the water pump impeller?
For preventative maintenance, it is recommended to replace the impeller every 1 to 2 years or every 100-200 hours of operation. This interval can be shorter if you frequently operate in sandy, silty, or saltwater conditions.

OEM vs. Aftermarket?
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.

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

What is your warranty and return policy?
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.