Water Pump Repair Kit – Fits Yamaha 6–15 HP (Replaces 63V-44301-00, 63V-W0078-00)

Water Pump Repair Kit – Fits Yamaha 6–15 HP (Replaces 63V-44301-00, 63V-W0078-00)

This water pump repair kit is designed for a range of Yamaha 4-stroke and 2-stroke outboard engines. It provides the necessary components to restore the performance of your engine's cooling system, preventing overheating and ensuring reliability.

This kit is a direct replacement for Yamaha OEM part numbers 63V-W0078-00-00, 63V-W0078-01-00, 63V-W0078-02-00, 63V-W0078-03-00, 63V-W0078-04-00, as well as aftermarket parts Sierra 18-3356 / 18-3412, HJ YHJB-63V, MAL 9-43254, and PAF PAF15-06060001.

• Installation Location: Mounts in the lower unit (gearcase) of the outboard motor.
• Core Components: Includes the impeller, cartridge insert, outer plate, and all required seals and bolts for a standard rebuild.
• Engine Fitment: Compatible with Yamaha 4-Stroke models from 6 HP to 15 HP and 2-Stroke models from 9.9 HP to 15 HP (1998–2008).

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.

Yamaha 4-Stroke Models

Yamaha 2-Stroke Models

Technical Specifications

Package Contents

• 1 x Insert, Cartridge (63V-44322-00-00)
• 1 x Outer Plate, Cartridge (63V-44323-00-00)
• 1 x Impeller (63V-44352-01-00)
• 1 x Water Seal Damper 2 (647-44366-00-00)
• 1 x Key, Woodruff (664-44338-00-00)
• 4 x Bolt (97095-08045-00)
• 1 x O-ring (93210-44704)

Installation Guide

1. Safety First: Disconnect the battery and remove the spark plug wires before beginning work.
2. Access Lower Unit: Place the outboard in a secure position. Drain the gearcase oil into a suitable container.
3. Remove Lower Unit: Unbolt the lower unit (gearcase) from the engine leg. Keep track of all bolts and their locations.
4. Disassemble Pump: With the lower unit removed, unbolt and remove the water pump housing to access the old impeller and gaskets.
5. Clean Surfaces: Thoroughly clean all mating surfaces, removing any old gasket material or sealant.
6. Install New Components: Install the new cartridge insert, outer plate, water seal, and O-ring from the kit.
7. Install Impeller: Slide the new Woodruff key onto the driveshaft flat spot and install the new impeller. Important: Rotate the driveshaft clockwise while pushing down to correctly seat the impeller vanes.
8. Reassemble Pump: Reinstall the water pump housing and tighten the bolts to the manufacturer's specified torque.
9. Reattach Lower Unit: Reinstall the lower unit to the engine leg, ensuring the driveshaft and shift shaft align correctly.
10. Final Checks: Refill the gearcase with fresh oil. Reconnect the battery and spark plug wires.
11. Test Operation: Start the engine in water and immediately check for a steady stream of water from the telltale outlet.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my Yamaha engine?
A: First, check the "Compatible Engine Models" table to see if your model is listed. This kit is designed for specific Yamaha 4-stroke (6-15 HP) and 2-stroke (9.9-15 HP) models within the 1998–2008 year range. You can use the linked Yamaha Serial Number Guide to verify your engine details precisely.

Q: What are the signs that my water pump needs to be replaced?
A: The most common signs of a failing water pump are the engine running hotter than normal or a weak, inconsistent, or non-existent water stream from the "telltale" outlet. During a visual inspection, a worn, cracked, or brittle impeller also indicates an immediate need for replacement.

Q: Does this kit include the entire water pump housing?
A: No, this is a repair kit containing the wearable internal components like the impeller, cartridge plates, gaskets, and bolts. The main water pump housing (Yamaha Part No. 63V-44301-00-00) is a separate component and is not included in this kit.

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.