Water Pump Impeller Repair Kit – Fits Mercury/Mercruiser Alpha 1 Gen 2 & Outboards 40-300HP (Replaces 47-43026Q06, 8M0100526)

Water Pump Impeller Repair Kit – Fits Mercury/Mercruiser Alpha 1 Gen 2 & Outboards 40-300HP

This water pump impeller repair kit provides the components needed for a complete overhaul of your engine's cooling system. It is designed for a direct fit on a wide range of Mercury/Mercruiser outboards and sterndrives, including Mercury Mariner 4-stroke 40-60HP BigFoot/Command Thrust models, various 2-stroke outboards from 60HP to 250HP, all Verado 135-300HP models with 4.80" gear cases, and MerCruiser Alpha One Gen II drives.

This kit serves as a direct replacement for Mercury part numbers 47-43026Q06, 8M0100526, 47-43026Q5, 47-43026T10, 47-43026T11, 47-43026T6, 47-43026T7, 47-43026T8, and Sierra 18-3214, 18-3265.

• Includes a new impeller, wear plate, gaskets, seals, and hardware for a comprehensive service.
• Impeller is constructed from a durable neoprene elastomer compound for improved flexibility and long service life.
• Installation requires the removal and disassembly of the lower unit.

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/Mercruiser Outboards

Mercury/Mercruiser Sterndrives

Technical Specifications

Package Contents

• 1 x Impeller (47-43026Q02)
• 1 x Wear Plate (817276)
• 1 x Impeller Key (28-8M0032833)
• 1 x Seal Ring Gasket (26-45577)
• 1 x Impeller Gasket (27-817277)
• 1 x Face Seal and Tool (26-816575A2)
• 2 x O-Ring (25-21836)
• 1 x Grommet
• 2 x Washer
• 2 x Drain Screw Gasket (26-830749)

Installation Guide

Professional installation is recommended. The following is a general guide and may not match your specific engine model.

1. Disconnect the Battery: Disconnect the negative battery cable to prevent accidental starting.
2. Drain Gear Lube: Place a drain pan under the lower unit and remove the upper and lower drain/fill screws to drain the gear lube.
3. Remove the Lower Unit: Remove the bolts securing the lower unit to the engine. The number and location of bolts vary by model. The unit is heavy; be prepared to support it.
4. Disassemble the Water Pump: With the lower unit removed, locate and unbolt the water pump housing.
5. Remove Old Components: Remove the old impeller, wear plate, gaskets, and seals. Clean all mating surfaces thoroughly, removing any old gasket material or debris.
6. Install New Components: Install the new wear plate, gaskets, and key. Slide the new impeller onto the driveshaft (a small amount of soapy water can help). Ensure it is oriented correctly.
7. Reassemble the Pump: Install the new seals and re-bolt the housing according to your service manual's torque specifications.
8. Reinstall Lower Unit: Reattach the lower unit to the engine, ensuring the driveshaft, shift shaft, and water tube are correctly aligned. Refill the gearcase with fresh lubricant before starting the engine.

Troubleshooting & FAQ

How do I confirm this fits my engine?
The most reliable way is to verify your engine's serial number against the compatible ranges listed in the 'Compatible Engine Models' table. For Mercury owners, use the provided serial number guide to find your number and confirm a match before ordering.

What are the signs of a failing water pump impeller?
Common signs include the engine overheating at idle or low speeds, a weak or non-existent "telltale" water stream, or a visible decrease in water pressure on the gauge. Brittle, cracked, or missing impeller vanes are also clear indicators of failure.

How often should I replace my water pump impeller?
For preventative maintenance, it is recommended to inspect the impeller annually and replace it every 1-2 years, or every 100-200 hours of operation, depending on usage conditions. If you operate in saltwater or silty/sandy conditions, more frequent replacement is advised.

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.