Water Pump Impeller – Fits Yamaha 20HP-50HP Outboards (Replaces 6H4-44352-00, 6H4-44352-01, 6H4-44352-02)

Water Pump Impeller – Fits Yamaha 20HP-50HP Outboards (Replaces 6H4-44352-00, 6H4-44352-01, 6H4-44352-02)

This water pump impeller is designed for a wide range of Yamaha 2-stroke and 4-stroke outboard motors from 20 HP to 50 HP (model years 1984–2005), including C, CV, F, P, and T series models. It ensures proper engine cooling by replacing worn or damaged original impellers.

This component is a direct replacement for Yamaha part numbers 6H4-44352-00, 6H4-44352-01, 6H4-44352-02, and Sierra 18-3068.

• Installation Type: Direct replacement for OEM part.
• Required for Installation: Requires woodruff key 90280-03024 (not included).

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 Yamaha owners, here’s a guide to help you identify your engine’s serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Impeller (6H4-44352-02)

Installation Guide

1. Disconnect the Battery: Ensure the engine is off and the battery is disconnected for safety.
2. Position the Engine: Tilt the engine up and secure it.
3. Drain Gearcase Lube: Place a drain pan under the lower unit and remove the drain and vent screws to drain the lubricant.
4. Remove the Lower Unit: Unbolt the lower unit (gearcase) from the engine's midsection. You may need to disconnect the speedometer tube or shift linkage.
5. Access the Water Pump: With the lower unit removed, locate and unbolt the water pump housing cover.
6. Remove Old Impeller: Note the rotational direction of the old impeller vanes before removing it from the driveshaft. Remove the old gaskets and the woodruff key.
7. Install New Impeller: Clean all housing surfaces. Install the new woodruff key, then slide the new impeller onto the shaft, twisting it in the direction of engine rotation to bend the vanes correctly.
8. Reassemble Pump Housing: Install new gaskets and plates as needed, then bolt the housing cover back on, ensuring a tight seal.
9. Reattach Lower Unit: Reconnect any linkages and carefully bolt the lower unit back onto the engine.
10. Refill Gear Lube: Fill the gearcase with fresh marine gear lubricant from the bottom drain hole until it seeps out the top vent hole. Reinstall both screws.
11. Test Operation: Reconnect the battery, start the engine in water, and confirm a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this fits my engine?
First, check your original part number against our cross-reference list. Second, review the compatible engine models table to find your specific model and year. For assistance, use the Yamaha Serial Number Guide linked above to identify your engine details.

What are the signs of a a failing impeller?
Common symptoms include the engine overheating, a weak or non-existent water stream from the "tell-tale" indicator, or a high-temperature warning alarm from the console.

How often should I replace the water pump impeller?
For preventative maintenance, it is recommended to replace the impeller every 1 to 2 years or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater, sandy/silty environments).

Does this impeller include the installation hardware?
No, this package contains only the impeller. The woodruff key (part number 90280-03024), gaskets, and housing are sold separately. Always check if a complete water pump kit is better suited for your needs.

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.