6H4-W006A-00 Water Pump Repair Kit for Yamaha 50HP 2-Stroke 3-Cylinder | JLM Marine

Water Pump Repair Kit – Fits Yamaha 50HP 2-Stroke 3-Cylinder (1984-1994)

This comprehensive water pump repair kit is engineered for Yamaha 50HP 2-Stroke 3-Cylinder outboard engines manufactured between 1984 and 1994. Designed to restore your cooling system to optimal performance, this kit includes all essential gaskets, seals, impeller, thermostat, and related components needed for a complete water pump overhaul.

Direct replacement for OEM part number 6H4-W006A-00, this aftermarket kit delivers reliable performance and proper fitment for your Yamaha outboard's cooling system maintenance.

• Complete rebuild kit with impeller, gaskets, thermostat, and wear plate
• Includes bonus fuel filter and gear oil pump for extended maintenance
• Suitable for 2-stroke marine applications requiring regular cooling system service

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

This complete repair kit includes the following components:

• 663-44315-A0 (Gasket) × 1
• 663-44316-A0 (Gasket) × 1
• 663-44322-00 (Cup, Insert) × 1
• 663-44323-00 (Plate, Wear) × 1
• 663-44324-A0 (Gasket) × 1
• 663-44366-00 (Grommet) × 1
• 90280-03024 (Key) × 1
• 6H4-44352-02 (Impeller) × 1
• 97080-08045 (Bolt) × 2
• 97080-08055 (Bolt) × 2
• 61N-24560-00 (Fuel Filter) × 1
• 6E5-12411-30 (Thermostat) × 1
• 6J8-12414-A0 (Thermostat Gasket) × 1
• 90430-08020 (Drain Gasket) × 4
• 91490-30025 (Cotter Pin) × 1
• 24OP149 (Gear Oil Pump) × 1

Installation Guide

1. Disconnect the engine from the fuel supply and ensure the engine is completely cool before beginning work.
2. Remove the lower unit by loosening the mounting bolts and carefully separating it from the mid-section.
3. Locate the water pump housing on the top of the lower unit driveshaft and remove the securing bolts.
4. Carefully remove the old impeller, noting the direction of the blades for proper installation.
5. Clean all gasket surfaces thoroughly, removing any old gasket material and debris.
6. Install the new wear plate (663-44323-00) into the pump housing with the smooth side facing the impeller.
7. Lubricate the new impeller with water-resistant marine grease and install it with blades facing the correct rotation direction.
8. Place the insert cup (663-44322-00) over the impeller and position the new gaskets in their respective locations.
9. Install the thermostat (6E5-12411-30) with its new gasket (6J8-12414-A0) into the thermostat housing.
10. Reassemble the water pump housing, torquing all bolts to manufacturer specifications using the provided new bolts.
11. Reattach the lower unit to the mid-section, ensuring proper alignment and secure all mounting hardware.
12. Test the cooling system by running the engine in a test tank or on-water, verifying proper water flow from the tell-tale indicator.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my specific Yamaha 50HP engine?
A: Verify that your engine is a 2-stroke 3-cylinder model manufactured between 1984 and 1994. Cross-reference your current water pump kit's OEM number (6H4-W006A-00) or consult your engine's parts diagram using the Yamaha serial number guide linked above.

Q: How often should I replace my water pump impeller and related components?
A: Yamaha recommends inspecting the water pump annually and replacing the impeller every 2-3 years or 200-300 hours of operation, whichever comes first. If you notice reduced water flow, overheating, or visible impeller damage, replace immediately.

Q: What are the signs that my water pump is failing?
A: Common symptoms include weak or no water discharge from the tell-tale indicator, engine overheating warnings, steam from the engine, reduced water pressure, or unusual noises from the lower unit. Address these issues promptly to prevent engine damage.

Q: Do I need to replace all components in the kit, or can I just change the impeller?
A: While the impeller is the primary wear item, it's highly recommended to replace all gaskets, seals, and the wear plate during service. Old gaskets can cause leaks, and a worn wear plate reduces impeller efficiency and lifespan.

Q: What's the difference between this aftermarket kit and the original Yamaha OEM kit?
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.