Water Pump Repair Kit – Fits Yamaha 40/50/60HP 2-Stroke & 4-Stroke (Replaces 63D-W0078-01-00)

Water Pump Repair Kit – Fits Yamaha 40/50/60HP 2-Stroke & 4-Stroke (Replaces 63D-W0078-01-00)

This water pump repair kit provides all the necessary components to restore the cooling system on select Yamaha 2-stroke and 4-stroke outboard engines. It is designed to fit a range of 40, 50, and 60 horsepower models, ensuring a precise match for reliable performance.

This kit is a direct replacement for Yamaha part number 63D-W0078-01-00 and Sierra part number 18-3434.

• Includes all essential components for a complete water pump rebuild, including the impeller, housing, gaskets, and bolts.
• Engineered as a direct OEM replacement for straightforward installation without modifications.
• Fits a wide range of Yamaha engines, including 40-50HP 2-Stroke (1994-2005) and F40/F50/F60 4-Stroke models.

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 2-Stroke Models

Yamaha 4-Stroke Models

Technical Specifications

Package Contents

• 1 x Cartridge Insert (63D-44322-00-00)
• 1 x Impeller (6H3-44352-00-00)
• 1 x Water Pump Housing Cover (63D-44312-00-00)
• 1 x Cartridge Outer Plate (63D-44323-00-00)
• 1 x O-Ring (93210-59MG7-00)
• 1 x Water Pump Gasket (63D-44316-00-00)
• 4 x Bolts With Washers (90119-08M15-00)
• 1 x Water Seal Damper 2 (663-44366-00-00)
• 1 x Woodruff Key (90280-03024-00)

Installation Guide

1. Disconnect the battery and remove the engine cover.
2. Shift the outboard into neutral and remove the bolts securing the lower unit (gearcase).
3. Carefully lower and remove the gearcase from the drive shaft housing.
4. Unbolt and remove the old water pump housing assembly from the gearcase. Note the orientation of the parts.
5. Clean the mounting surfaces on the gearcase, removing any old gasket material or debris.
6. Install the new woodruff key, impeller, plates, and gaskets as provided in the kit.
7. Secure the new water pump housing cover with the new bolts and washers, tightening to the manufacturer's specified torque.
8. Apply marine grease to the drive shaft splines and reinstall the lower unit.
9. Reconnect the battery and test the engine in a suitable water source, ensuring a strong stream from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this kit fits my engine?
First, check the "Compatible Engine Models" tables on this page. For Yamaha owners, we highly recommend using the Yamaha Serial Number Guide to confirm your exact model and year before ordering.

What are the signs of a failing water pump?
Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and in severe cases, a steam or high-temperature alarm from your console.

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

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.