Water Pump Impeller Kit – Fits Mercury/Mariner 40-300 HP & Alpha One Gen II (Replaces 47-43026Q06, 8M0100526)

Water Pump Impeller Kit – Fits Mercury/Mariner 40-300 HP & Alpha One Gen II (Replaces 47-43026Q06, 8M0100526)

This water pump impeller service kit is designed for a wide range of Mercury/Mariner 2-stroke and 4-stroke outboards from 40 to 300 HP, as well as MerCruiser Alpha One Gen II sterndrives and select Honda outboards. It provides a reliable solution for maintaining your engine’s cooling system.

This kit is a direct replacement for Mercury part numbers 47-43026Q06, 47-43026T11, and 8M0100526; Honda 19021-ZW1-003; Sierra 18-3214 and 18-3265; and GLM 12043 and 12080.

• Complete Service Kit: Includes a new impeller, wear plate, gaskets, seals, and o-rings for a full replacement.
• Enhanced Durability: Impeller elastomers provide improved flexibility across a broad range of temperatures for consistent performance.
• Direct Fit: Engineered to meet OEM specifications for a direct, hassle-free installation.

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.

Confirm your engine model/year in the table below.

Mercury/Mariner Outboards

MerCruiser

Honda

Technical Specifications

Package Contents

• 1 x Water Pump Impeller (47-43026Q06)
• 1 x Face Plate (26-816575A2)
• 1 x Impeller Key
• 2 x Impeller Gasket (27-817277)
• 1 x Impeller Gasket (27-430331)
• 1 x Seal Ring Gasket (26-45577)
• 2 x O-Ring (25-21836)
• 1 x Face Seal
• 1 x Cover
• 1 x Washer

Installation Guide

1. Safety First: Disconnect the battery and ensure the engine is securely tilted or supported.
2. Access Lower Unit: Drain the gearcase oil and remove the lower unit (gearcase) from the outboard leg.
3. Remove Pump Housing: Locate the water pump assembly on top of the gearcase. Unbolt and carefully lift the housing off. It may be stuck; avoid using excessive force.
4. Inspect and Remove Old Parts: Take note of the old components' orientation. Remove the old impeller, wear plate, gaskets, and seals. The impeller key may be loose on the driveshaft.
5. Clean Surfaces: Thoroughly clean the mounting surfaces of the housing and gearcase, removing any old gasket material or sealant residue.
6. Install New Components: Lightly grease the new gaskets and O-rings. Install the new wear plate, gaskets, and impeller key. Slide the new impeller onto the driveshaft while turning the shaft clockwise to bed the vanes correctly.
7. Reassemble: Install the new seals into the housing. Carefully lower the housing over the impeller, ensuring a snug fit. Apply thread locker to the bolts and tighten them to the manufacturer's recommended torque specification.
8. Reinstall and Test: Reinstall the lower unit, refilling it with fresh gear oil. Reconnect the battery, start the engine in water, and confirm that there is a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

Q: How can I be sure this kit fits my specific engine model?

A: The best way is to match the OEM part number from your engine’s service manual or by looking up your model and serial number in the parts catalog. Cross-reference this number with the list provided in our compatibility tables. When in doubt, contact us with your engine details.

Q: What are the common symptoms of a worn or failed water pump impeller?

A: The most common signs include the engine overheating at idle or low speeds, a weak or non-existent stream of water from the "tell-tale" outlet, or a high-temperature alarm from your helm gauges.

Q: How often should I replace my engine's water pump impeller?

A: As a general rule, it is recommended to inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of use, whichever comes first. Refer to your engine’s service manual for specific maintenance intervals.

Q: Is this an OEM part?

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.