Water Pump Impeller Kit – Fits Mercury/Mariner Outboard 40-250 HP and MerCruiser Alpha One Gen 2

Water Pump Impeller Kit – Fits Mercury/Mariner Outboard 40-250 HP and MerCruiser Alpha One Gen 2 (Replaces 47-43026Q06, 8M0100526)

This aftermarket water pump impeller kit is designed for a wide range of Mercury/Mariner outboard engines from 40 to 250 HP, including 4-stroke, 2-stroke, and Verado models manufactured from 1992 to the present. It is also compatible with MerCruiser Alpha One Gen 2 stern drives (serial number 0D469859 and above).

It serves as a direct replacement for several OEM and aftermarket part numbers, ensuring a precise fit and reliable performance. This kit contains all the necessary components for a complete water pump service.

• Installation: Mounts directly to the engine/drive lower unit.
• Materials: Features a durable neoprene impeller and a housing constructed from robust metal alloys.
• Complete Kit: Includes the impeller, face plate, gaskets, seals, and key needed for a full replacement.

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.

Mercury/Mariner Outboard

MerCruiser Stern Drives

Technical Specifications

Package Contents

• 1 x Neoprene Impeller (47-43026-T2/47-43026Q02)
• 1 x Face Plate (8172761)
• 1 x Water Pump Gasket (430331/8172771)
• 1 x Impeller Key
• 1 x O-ring
• 1 x Face Seal
• Note: Kit contents may vary. Some kits include a seating tool, while others do not. Additional gaskets or seals may be included.

Installation Guide

1. Safety First: Disconnect the battery and remove the ignition key before starting any work.
2. Access the Lower Unit: Trim the outboard up and remove the propeller. Unbolt and carefully lower the gearcase (lower unit) from the engine.
3. Disassemble the Pump: Locate the water pump housing on top of the gearcase. Remove the bolts securing the housing cover.
4. Inspect and Remove Old Parts: Take note of the old impeller's orientation. Remove the old impeller, gasket, wear plate, and any seals. Clean all surfaces thoroughly.
5. Install New Components: Lightly lubricate the new impeller with soapy water or silicone grease. Install the new key, wear plate, gasket, and impeller, rotating the driveshaft clockwise to set the vanes correctly.
6. Reassemble the Housing: Install the new gasket and face plate/cover. Torque the housing bolts to the manufacturer's specification.
7. Reinstall Lower Unit: Guide the driveshaft back into the engine, ensuring the water tube aligns correctly. Bolt the gearcase back in place and reinstall the propeller.
8. Test the System: Reconnect the battery. With the outboard submerged in water, start the engine and verify that a steady stream of water is exiting the "telltale" outlet.

Troubleshooting & FAQ

How do I confirm this kit fits my engine?
First, check the compatibility tables on this page against your engine's model, horsepower, and serial number range. For Mercury/Mariner owners, we recommend using the Mercury Serial Number Guide to verify your details. Cross-referencing the OEM part number (47-43026Q06 or 8M0100526) with your engine's service manual is the most reliable method.

What are the signs of a failing water pump impeller?
Common symptoms include a weak or non-existent water stream from the telltale outlet, engine overheating alarms, or a noticeable decrease in engine performance. A visual inspection may reveal cracked, brittle, or worn impeller vanes.

How often should I replace my water pump impeller?
As a general maintenance guideline, it is recommended to inspect your water pump annually and replace the impeller every 1-2 years or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater).

Is this an OEM part?
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.