Water Pump Impeller – Fits Yamaha 40-70 HP Outboards (Replaces 6H3-44352-00-00)

Water Pump Impeller – Fits Yamaha 40-70 HP Outboards (Replaces 6H3-44352-00-00)

This water pump impeller is designed for Yamaha 2-stroke and 4-stroke outboards from 40 HP to 70 HP (model years approximately 1984–2019). It is compatible with a wide range of models, including C-series, F-series, P-series, and T-series engines.

This part is a direct replacement for Yamaha part numbers 6H3-44352-00-00, 6H3-44352-01-00, and 697-44352-00-00. It also replaces Sierra aftermarket part 18-3069.

• Installation: Direct replacement requiring standard hand tools.
• Material: Constructed from high-quality, durable neoprene rubber for reliable performance.
• Design: Features a self-priming design that uses the pumped fluid for lubrication.

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 Water Pump Impeller (Replaces 6H3-44352-00-00)

Installation Guide

1. Disconnect Power: Ensure the engine is off and disconnect the battery cables.
2. Remove Lower Unit: Unbolt and carefully lower the gearcase (lower unit) from the outboard's driveshaft housing.
3. Access Impeller Housing: Locate and remove the bolts securing the water pump housing cover.
4. Inspect Old Impeller: Note the rotational direction of the existing impeller's blades before removing it. They should be curved in the direction of driveshaft rotation.
5. Remove Old Components: Take out the old impeller, Woodruff key, and any gaskets or seals.
6. Clean Surfaces: Thoroughly clean the inside of the pump housing and the base plate, removing any old gasket material or debris.
7. Install New Impeller: Apply a light coat of marine grease or soap-and-water solution to the inside of the housing. Insert the new Woodruff key into the driveshaft and slide the new impeller down, twisting it in the correct rotational direction to bed the blades.
8. Reassemble Pump: Reinstall the water pump housing and torque the bolts to the manufacturer's specification.
9. Reinstall Lower Unit: Carefully guide the lower unit back into place, ensuring the driveshaft, shift shaft, and water tube align correctly. Secure with bolts.
10. Test Operation: Reconnect the battery. Start the engine in a suitable water supply (using flushing muffs or in the water) and confirm a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this impeller fits my engine?
First, check if your OEM part number is listed in our Part Number Cross-Reference table. Second, verify your engine's model, HP, and year against the Compatible Engine Models list. For Yamaha owners, we provide a Serial Number Guide to help you find your exact model details.

What are the signs of a failing water pump impeller?
Common signs include a weak or non-existent water stream from the engine's tell-tale outlet, an overheating alarm sounding, or the engine going into a power-reduction mode (Limp Mode). Visual inspection may also reveal cracked, brittle, or missing blades on the old impeller.

How often should I replace the impeller?
For preventative maintenance, we recommend replacing the impeller every 1-2 years or every 100-200 hours of use. If you frequently operate in sandy, silty, or saltwater, more frequent inspections and replacements are 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.