Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP Outboard (Replaces 682-W0078-A1-00)

Water Pump Impeller Kit – Fits Yamaha 9.9/15 HP Outboard (Replaces 682-W0078-A1-00)

This water pump impeller repair kit is designed for Yamaha 9.9 HP and 15 HP 2-stroke outboard engines (1984-1995) and select 4-stroke models (1985-2004). It also fits corresponding Mariner outboards that utilize the same part specifications.

This kit is a direct replacement for Yamaha part numbers 682-W0078-00-00, 682-W0078-01-00, 682-W0078-A1-00, 682-W0078-A2-00, and 682-W0078-A3-00.

• Installation Type: Direct OEM replacement
• Materials: Features a marine-grade stainless steel alloy housing with a durable rubber impeller.
• Quality Standard: Manufactured in an ISO9002 certified facility to meet or exceed OEM specifications.

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 Models

Mariner Models

Technical Specifications

Package Contents

• 1 x Impeller (Replaces 682-W0078-A1)

Installation Guide

1. Disconnect the battery and remove the engine cover.
2. Locate the lower unit and drain the gearcase oil.
3. Unbolt and carefully separate the lower unit from the upper casing.
4. Remove the water pump housing bolts and lift the housing to expose the old impeller.
5. Take note of the old impeller's vane direction before removing it.
6. Clean the housing interior and inspect it for wear or damage.
7. Install the new impeller, ensuring the vanes are oriented correctly (typically clockwise).
8. Install the new gasket and re-seat the housing, tightening bolts to the manufacturer's torque specs.
9. Re-attach the lower unit, ensuring the driveshaft and water tube align.
10. Refill the gearcase with fresh oil and re-attach the engine cover.
11. Start the engine using a water supply (flushing muffs) and verify water is exiting the tell-tale port.

Troubleshooting & FAQ

How do I confirm this kit fits my specific engine?
The best method is to match your engine's model, horsepower, and year against the compatibility tables above. For certainty, cross-reference the OEM part number stamped on your existing water pump or found in your service manual with the numbers listed in our cross-reference table.

What are the signs of a failing water pump impeller?
Common signs include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and in severe cases, steam from the exhaust. The impeller itself may be brittle, cracked, or have broken vanes.

How often should I replace the impeller?
For preventative maintenance, it is recommended to inspect the impeller annually and replace it every 1-2 years, depending on usage (hours) and water conditions (saltwater, sandy/silty water). Do not wait for it to fail, as overheating can cause severe engine damage.

OEM vs. Aftermarket?
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.

How fast do you ship and how much does it cost?
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.

What is your warranty and return policy?
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.