Water Pump Impeller Kit – Fits Yamaha 4HP & 5HP Outboards (Replaces 6E0-W0078-A2-00)

Water Pump Impeller Kit – Fits Yamaha 4HP & 5HP Outboards (Replaces 6E0-W0078-A2-00)

This water pump impeller kit is a direct replacement for specific Yamaha and Mariner outboard models. It is designed to restore cooling system performance and prevent engine overheating. The kit fits Yamaha 2-stroke 4HP (1984–1999) and 5HP (1984–2002) models, as well as 4-stroke F4 (1999–2008) models. It is also compatible with select 1996 Mariner 4HP and 5HP outboards that have 6E0 or 6E3 serial numbers.

This kit directly replaces multiple Yamaha part numbers, including 6E0-W0078-A2-00, 6E0-W0078-00-00, 6E0-W0078-01-00, 6E0-W0078-02-00, 6E0-W0078-A3-00, 6E0-W0078-A4-00, 6E0-W0078-A5-00, 68D-WG078-00-00, and 67D-W0078-00-00.

• Complete Assembly: Includes all necessary components for a full water pump rebuild, including the housing, gasket, impeller, and bolts.
• Direct Installation: Manufactured to meet OEM specifications for a precise fit and straightforward installation.
• Durable Materials: Features a marine-grade aluminum housing for corrosion resistance and longevity.

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.

Confirm your engine model/year in the table below.

Yamaha

Mariner

Technical Specifications

Package Contents

• 1 x Housing, Water Pump (6E0-44311-00-00)
• 1 x Gasket, Water Pump (6E0-44315-A0-00)
• 1 x Insert, Cartridge (6E0-44322-02-00)
• 1 x Outer Plate, Cartridge (6E0-44323-00-00)
• 1 x Impeller (6E0-44352-00-00)
• 1 x Damper, Water Seal (6E0-44366-00-00)
• 1 x Pin, Dowel (93604-09066-00)
• 4 x Bolt (97080-06045-00)

Installation Guide

1. Safety First: Disconnect the battery and remove the propeller before starting any work.
2. Access the Pump: Drain the gearcase oil and remove the lower unit (gearcase) from the outboard motor.
3. Remove Old Housing: Carefully unbolt and remove the old water pump housing to expose the impeller.
4. Replace Components: Take out the old impeller, plate, and gaskets. Clean all surfaces thoroughly.
5. Install New Parts: Install the new components from the kit in the reverse order of removal. Ensure the impeller key is properly seated.
6. Reassemble: Reattach the water pump housing, tightening bolts to the manufacturer's recommended torque.
7. Final Steps: Reinstall the lower unit, refill the gearcase oil, and reattach the propeller.
8. Test Operation: Start the engine in a test tank or with a water flusher to confirm a strong, steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this fits my engine?
A: Check the "Compatible Engine Models" table carefully. For Yamaha and Mariner models, it's critical to match your engine's model, horsepower, and year range. For the specified Mariner models, you must also verify your engine has a 6E0 or 6E3 serial number.

Q: What are the signs of a failing water pump impeller?
A: Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, or a melted water pump housing.

Q: How often should the impeller be replaced?
A: As a general maintenance rule, it is recommended to inspect and/or replace the water pump impeller every 1 to 2 years, or every 100-200 hours of use, to ensure reliable engine cooling.

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.