663-44324-A0 Water Pump Impeller Gasket for Yamaha 40HP 50HP | JLM Marine

Water Pump Impeller Gasket – Fits Yamaha 2-Stroke 40HP & 50HP Outboards (663-44324-A0)

This water pump impeller gasket is engineered to fit Yamaha 2-stroke outboard engines from 40HP to 55HP across multiple model years. It ensures a reliable seal within your water pump housing, preventing leaks and maintaining optimal cooling system performance.

Direct replacement for Yamaha OEM part number 663-44324-A0. Designed for straightforward installation in compatible Yamaha outboard models spanning 1984–1996.

• Precision-cut gasket for water pump impeller assembly
• Compatible with Yamaha 2-stroke engines: 40HP, 50HP, and 55HP
• Essential component for water pump service and rebuild

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

Each package includes:

• 1 x Water Pump Impeller Gasket (663-44324-A0)

Installation Guide

1. Disconnect the fuel line and remove the engine cowling to access the lower unit. Ensure the engine is completely cool before beginning work.
2. Drain the lower unit gear oil and remove the propeller. Disconnect the shift linkage carefully.
3. Unbolt and remove the lower unit from the midsection. Set it on a clean workspace.
4. Remove the water pump housing bolts and carefully separate the housing. Take note of the orientation of existing components.
5. Remove the old impeller gasket and inspect the housing and base plate for corrosion or damage. Clean all mating surfaces thoroughly.
6. Position the new gasket (663-44324-A0) onto the water pump base plate, ensuring proper alignment with all bolt holes.
7. Install the impeller, drive key, and any other water pump components per your service manual specifications.
8. Reassemble the water pump housing, torquing bolts to manufacturer specifications in a crisscross pattern. Do not overtighten.
9. Reinstall the lower unit onto the midsection, reconnect the shift linkage, and secure all mounting bolts.
10. Refill the lower unit with the correct grade and quantity of gear oil. Reinstall the propeller.
11. Reconnect the fuel line and reinstall the cowling. Start the engine and verify strong water flow from the tell-tale (pilot hole).
12. Check for leaks around the water pump housing and lower unit seals during the test run.

Troubleshooting & FAQ

Q: How do I confirm this gasket fits my Yamaha outboard?
A: Check the compatibility table above for your engine's horsepower, stroke type, and year range. Cross-reference your existing part number (663-44324-A0) or consult your engine's parts diagram using the Yamaha Parts Catalog link provided.

Q: How often should I replace the water pump impeller gasket?
A: Replace the gasket every time you service or replace the water pump impeller—typically every 2–3 years or 200–300 hours of operation. Always use a new gasket; never reuse old gaskets as they may leak.

Q: What are the signs that my water pump gasket is failing?
A: Symptoms include weak or no water flow from the tell-tale, engine overheating, coolant leaks around the lower unit, or visible water seepage from the pump housing. Inspect and replace the gasket during routine water pump maintenance.

Q: Can I reuse the old gasket if it looks okay?
A: No. Gaskets compress and conform to mating surfaces during use; reusing them risks improper sealing, leaks, and potential engine damage from overheating. Always install a new gasket during water pump service.

Q: Is this an OEM or aftermarket part?
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.