663-44315-A0 Water Pump Impeller Gasket for Yamaha | JLM Marine

Water Pump Impeller Gasket – Fits Yamaha 2-Stroke 40–50 HP Outboards

This water pump impeller gasket is engineered to fit Yamaha 2-stroke outboard engines ranging from 40 HP to 50 HP across multiple years and series. It provides a reliable seal for your water pump assembly, ensuring optimal cooling performance and preventing leaks in your marine outboard system.

This gasket directly replaces Yamaha OEM part number 663-44315-A0, offering seamless compatibility with your original equipment. Designed for straightforward installation, it restores your water pump's integrity and extends engine life.

• Fits Yamaha 2-stroke outboards: 40 HP (1984–1994), 50 HP standard and Pro Series models
• Direct replacement for OEM part number 663-44315-A0
• Single gasket component for clean, efficient sealing

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

Your kit contains the following components:

• 1 × Water Pump Impeller Gasket

Installation Guide

1. Disconnect the spark plug wire to prevent accidental engine start during maintenance.
2. Remove the lower unit from the outboard motor following your engine's service manual.
3. Disassemble the water pump housing by removing the retaining bolts and carefully separating the components.
4. Remove the old impeller gasket and clean all mating surfaces thoroughly to remove residue, debris, and old sealant.
5. Inspect the water pump housing and impeller for wear or damage; replace any worn components as needed.
6. Position the new gasket on the mating surface, ensuring proper alignment with all bolt holes and water passages.
7. Reassemble the water pump housing, seating all components securely and evenly.
8. Torque the housing bolts to manufacturer specifications in a cross-pattern to ensure even compression.
9. Reinstall the lower unit onto the outboard motor, ensuring all splines and fittings engage correctly.
10. Reconnect the spark plug wire and test the cooling system by running the engine in a water tank or on muffs.
11. Check for leaks around the water pump area during the test run. Shut down immediately if leaks are detected.
12. Verify consistent water discharge from the telltale port, indicating proper cooling system function.

Troubleshooting & FAQ

Q: How do I confirm this gasket fits my Yamaha outboard?
A: Cross-reference your engine model and year with the compatibility table above. Verify your current OEM part number is 663-44315-A0 by checking your engine's parts diagram or service manual.

Q: How often should I replace the water pump impeller gasket?
A: Replace the gasket every time you service the water pump or replace the impeller, typically every 2–3 years or 200–300 operating hours, whichever comes first. Always use a new gasket to ensure a proper seal.

Q: What are the signs that my water pump gasket is failing?
A: Common symptoms include overheating, weak or no water flow from the telltale indicator, visible coolant leaks around the lower unit, or steam coming from the engine. Address these issues immediately to prevent engine damage.

Q: Can I reuse the old gasket if it looks intact?
A: No, gaskets are designed for single use. Reusing an old gasket can result in improper sealing, leaks, and overheating. Always install a new gasket during water pump service.

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.