Water Pump Impeller Repair Kit – Fits Yamaha 2HP 2-Stroke Outboards (Replaces 6A1-W0078-02-00)

Water Pump Impeller Repair Kit – Fits Yamaha 2HP 2-Stroke Outboards (Replaces 6A1-W0078-02-00)

This comprehensive repair kit is designed to restore the cooling system on Yamaha 2HP 2-Stroke outboard motors manufactured between 1984 and 2002. It provides all the necessary components to replace a worn or damaged water pump impeller and related parts, ensuring your engine maintains proper operating temperature and avoids overheating.

Each component is engineered for a direct fit, serving as a reliable alternative to original equipment manufacturer parts, ensuring a complete and lasting repair.

• Installation: Designed for direct replacement of the original components.
• Compatibility: Fits a wide range of Yamaha 2HP 2-stroke models from 1984-2002.
• Complete Kit: Includes impeller, housing components, seals, gaskets, and hardware for a full 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.

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

• 1 x Impeller (646-44352-01-00)
• 1 x Wear Plate (646-44323-00-00)
• 1 x Insert Cartridge Cup (646-44322-00-00)
• 1 x Cartridge Outer Plate (646-44323-00)
• 1 x Protector Oil Seal (6A1-44325-00-00)
• 1 x Oil Seal (93101-11M44-00)
• 1 x Damper, Water Seal (646-44366-01-00)
• 1 x "O" Ring (93210-19213-00)
• 2 x Dowel Pin (93604-09068-00)
• 2 x Bolt and Washer (97095-05016-00)

Installation Guide

1. Safety First: Disconnect the spark plug wire and ensure the engine is securely mounted on a stand or boat.
2. Remove Lower Unit: Shift the outboard into neutral. Loosen and remove the bolts connecting the lower gearcase to the upper leg housing.
3. Access Pump Housing: Place the lower unit on a workbench. Remove the bolts securing the water pump housing cover.
4. Disassemble Pump: Carefully lift off the housing. Slide the old impeller off the drive shaft, and remove the wear plate, gaskets, and seals.
5. Clean Surfaces: Thoroughly clean all mating surfaces, removing any old gasket material, sealant, or corrosion.
6. Install New Components: Place the new wear plate and gaskets. Slide the new impeller onto the drive shaft, turning it clockwise to bed the vanes correctly.
7. Reassemble Housing: Apply a light coat of marine grease to the inside of the new cup and install it. Re-install the housing and tighten the bolts to the manufacturer's specified torque.
8. Reinstall Lower Unit: Carefully guide the lower unit back into place, ensuring the drive shaft, shift shaft, and water tube align properly. Secure with bolts.
9. Test Operation: Reconnect the spark plug wire. Using a flush attachment or in the water, run the engine and confirm a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my exact Yamaha model?

A: Check the "Compatible Engine Models" table on this page. Match your engine model, horsepower, and year range. For complete certainty, use the Yamaha Serial Number Guide linked above to identify your engine and cross-reference the OEM part number (6A1-W0078-02-00).

Q: What are the signs of a failing water pump impeller?

A: Common signs include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and a dry, cracked, or brittle appearance of the old impeller upon inspection.

Q: How often should I replace my water pump impeller?

A: For optimal engine protection, it is recommended to inspect and/or replace the water pump impeller annually or every 100 hours of use, whichever comes first. This is especially important if you operate in saltwater or debris-heavy water.

Q: Does this kit fit Mariner outboards?

A: This kit is compatible with select 2HP 2-Stroke Mariner models that use the Yamaha 6A1-W0078-02-00 part number. However, you must verify compatibility by checking your engine's serial number and original part numbers, as Mariner used various manufacturers over the years.

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.