Water Pump Impeller Kit – Fits Mercury/Mariner/Honda 40-300 HP (Replaces 47-43026Q06)

Water Pump Impeller Kit – Fits Mercury/Mariner/Honda 40-300 HP (Replaces 47-43026Q06)

This water pump impeller service kit provides a reliable solution for maintaining the cooling system on a wide range of Mercury, Mariner, and Honda outboard engines, as well as Mercury Alpha One Gen 2 sterndrives. It is designed to meet or exceed OEM specifications for fit and performance, ensuring proper water circulation to prevent engine overheating.

Engineered as a direct replacement for multiple part numbers, this kit simplifies sourcing and installation. It is suitable for various 2-stroke and 4-stroke models from 40 HP up to 300 HP.

• Direct Replacement: Installs using existing hardware and connections with no modifications required.
• Complete Service Kit: Includes the impeller, wear plate, gaskets, seals, and o-rings necessary for a full service.
• Durable Construction: Features a 6-blade impeller designed for efficient water flow and long service life.

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 Outboard Models

Honda Outboard Models

Technical Specifications

Package Contents

• 1 x Water Pump Impeller (47-43026T2)
• 1 x Coupling Assembly (816597A1) - For 1991 and up models, S/N OD469859 and up
• 1 x Wear Plate (817276-1)
• 1 x Gasket (27-43033-1)
• 1 x O-Ring (25-21836)
• 1 x Seal (26-816575A2)
• 1 x Gasket (27-817277)

Installation Guide

1. Safety First: Disconnect the negative battery cable before starting work.
2. Access the Pump: Remove the lower unit (gearcase) from the outboard motor.
3. Disassemble: Carefully unbolt and remove the old water pump housing assembly. Note the order of the components.
4. Remove Old Parts: Take out the old impeller, keyway, wear plate, gaskets, and seals.
5. Clean Surfaces: Thoroughly clean all mating surfaces, removing any old gasket material or corrosion.
6. Install New Components: Place the new gasket and wear plate onto the gearcase. Insert the new keyway into the driveshaft.
7. Install Impeller: Slide the new impeller onto the driveshaft, turning it clockwise to bend the vanes correctly.
8. Reassemble Housing: Install the new seal in the housing, place the housing over the impeller, and fasten it with the bolts.
9. Torque Bolts: Tighten the housing bolts to the manufacturer's recommended torque specifications.
10. Reinstall Lower Unit: Reattach the lower unit to the outboard motor.
11. Test Operation: Reconnect the battery. Start the engine using a water supply (flushing muffs) and check for a steady water stream from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my engine?

A: The most reliable method is to check your engine's model, horsepower, and serial number against the detailed compatibility tables on this page. This kit is a direct replacement for several OEM part numbers, including Mercury/Mariner 47-43026Q06 and Honda 19021-ZW1-003. For Mercury owners, our linked serial number guide can help you verify your model.

Q: What are the signs of a failing water pump impeller?

A: The most common symptom of a bad impeller is engine overheating, often indicated by a warning alarm or gauge. Other signs include a weak or no water stream from the engine's "tell-tale" outlet, or an impeller that appears brittle, cracked, or has melted vanes upon inspection.

Q: How often should the impeller be replaced?

A: As a general maintenance rule, it is recommended to inspect the impeller annually and replace it every 1 to 2 years, or after every 100-200 hours of operation. Replacement frequency may depend on usage conditions, such as operating in saltwater or sandy/silty water, which can accelerate wear.

Q: OEM vs. Aftermarket?

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.