Water Pump Impeller Kit – Fits Mercury/Mercruiser Alpha 1 Gen 2 Drives & Outboards (Replaces 47-43026Q06)

Water Pump Impeller Kit – Fits Mercury/Mercruiser Alpha 1 Gen 2 Drives & Outboards (Replaces 47-43026Q06)

This water pump impeller service kit provides the necessary components for repairing the water pump on a wide range of Mercury/Mariner outboards from 40 HP to 250 HP, as well as Mercruiser Alpha One Gen 2 sterndrives (serial number 0D469859 and above).

Engineered to meet OEM specifications, this kit serves as a direct replacement for multiple part numbers, ensuring a reliable fit and restoration of your engine's cooling system performance. It is a comprehensive solution for routine maintenance or addressing overheating issues caused by a worn or failed impeller.

• Installation Type: Direct OEM replacement
• Key Component: Includes a high-quality, durable neoprene rubber impeller for optimal water flow.
• Complete Kit: Contains all necessary gaskets, seals, and plates for a full water pump 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 Impeller
• 1 x Key
• 1 x Impeller Plate
• 1 x Wear Plate
• 1 x Face Seal and Tool
• 2 x O-Ring
• 1 x Seal Ring Gasket
• 2 x Impeller Gasket
• 2 x Drain Screw Gasket

Explosion Diagram

Installation Guide

1. Ensure the engine is off and disconnect the battery for safety.
2. Place a drain pan and remove the lower unit from the sterndrive or outboard.
3. Unscrew the bolts holding the water pump housing cover and remove the cover.
4. Note the rotational direction of the old impeller's fins before removal.
5. Remove the old impeller, gaskets, wear plate, and any seals. Thoroughly clean all mating surfaces of debris and old gasket material.
6. Install the new wear plate, seals, and gaskets as supplied in the kit, matching them to the old parts.
7. Slide the new impeller onto the driveshaft with the new key, rotating the shaft in its operational direction (usually clockwise) to correctly bend the fins inside the housing.
8. Lightly lubricate the interior of the pump housing with marine grease.
9. Reinstall the pump housing, ensuring a snug fit, and tighten the bolts to the manufacturer's specified torque.
10. Reattach the lower unit to the engine.
11. Connect a water supply (flushing muffs) and start the engine, checking for a strong, steady stream from the water outlet to confirm a successful installation.

Troubleshooting & FAQ

How do I confirm this kit fits my Alpha One Gen 2 drive?
This kit is specifically designed for Mercruiser Alpha One Gen 2 drives with a serial number of 0D469859 and higher. Please locate and verify the serial number on your drive's identification plate before ordering.

What are the signs of a failing water pump impeller?
Common symptoms include the engine overheating, especially at idle or low speeds; a weak or intermittent water stream from the "telltale" outlet port; or finding brittle, cracked, or broken fins on the old impeller during inspection.

How often should I replace my water pump impeller?
For preventative maintenance, we recommend replacing the impeller every 1-2 years or every 100-200 hours of use. Frequency depends on operating conditions; saltwater and sandy/silty water environments may require more frequent changes.

The kit includes multiple gaskets. How do I choose the right one?
This kit fits a wide variety of models, so extra gaskets are included. To ensure you use the correct one, carefully match the new gasket to the exact shape and size of the original one you removed from your water pump housing.

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.