Water Pump Impeller Repair Kit – Fits Yamaha 6-30 HP Outboards (Replaces 63V-W0078-00/01, Sierra 18-3412/18-3433)

Water Pump Impeller Repair Kit – Fits Yamaha 6-30 HP Outboards

This water pump impeller repair kit is designed for select Yamaha 2-stroke (9.9–30 HP) and 4-stroke (6–15 HP) outboard motors. It serves as a direct replacement for original equipment, ensuring reliable performance for your engine's cooling system.

This kit provides a comprehensive solution by including the pump housing, impeller, wear plate, and all necessary gaskets and bolts for a complete overhaul.

• Direct Replacement: Engineered to replace Yamaha and Sierra part numbers for a precise fit.
• Complete Kit: Contains all essential components, including the pump housing, neoprene impeller, and stainless steel liner.
• Durable Construction: Features a tough nylon housing and a stainless steel wear plate for longevity and corrosion resistance.

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 Pump Housing (63V-44301-00)
• 1 x Water Pump Impeller (63V-44352-01-00)
• 1 x Cartridge Insert (63V-44322-00-00)
• 1 x Cartridge Outer Plate (63V-44323-00-00)
• 1 x Water Seal Damper (647-44366-00-00)
• 1 x Woodruff Key (63V-44338-00-00)
• 4 x Bolts (97080-08045-00)

Installation Guide

1. Disconnect Power: Disconnect the battery before beginning work.
2. Prepare Lower Unit: Place the outboard in neutral and drain the lower unit gear lube.
3. Remove Lower Unit: Loosen and remove the bolts securing the lower unit (gearcase) to the engine's upper section.
4. Access Water Pump: With the lower unit detached, locate and unbolt the water pump housing.
5. Remove Old Components: Carefully remove the old housing, impeller, wear plate, gaskets, and Woodruff key from the driveshaft.
6. Clean Surfaces: Thoroughly clean the mounting surfaces to ensure a proper seal with the new parts.
7. Install New Kit: Install the new Woodruff key, gaskets, wear plate, and cartridge insert. Slide the new impeller onto the driveshaft, turning it clockwise to seat the vanes.
8. Secure Housing: Place the new housing over the impeller and tighten the bolts to the manufacturer's specified torque.
9. Reassemble: Re-attach the lower unit to the engine, ensuring the driveshaft and shift shaft align correctly.
10. Final Steps: Refill the lower unit with fresh gear lube. Reconnect the battery.
11. Test Operation: Start the engine in water and verify that water is flowing strongly from the tell-tale outlet.

Troubleshooting & FAQ

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

A: Please review the compatibility tables on this page. For Yamaha owners, we highly recommend using the official Yamaha Serial Number Guide to confirm your engine's model and year before ordering.

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

A: The most common signs are engine overheating, a weak or non-existent water stream from the "tell-tale" outlet, and in some cases, a melting or deformed pump housing from excessive heat.

Q: How often should I replace the water pump impeller?

A: As a critical preventative maintenance item, it is recommended to replace the impeller every year or every 100 hours of operation, whichever comes first. Replacement is especially important if you operate in saltwater or sandy/silty conditions.

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.