Water Pump Impeller Kit for Yamaha 4 Stroke 15 20 HP - Repair Kit

In this review the Water Pump Impeller Kit for Yamaha 4 Stroke 15 20 HP is judged on fit, completeness, and ease of installation; it is aimed at boat owners who need a direct replacement for failed water pumps on F15C and F20 engines. The bottom line: this kit replaces Yamaha OEM numbers 6AH-W0078-00/01/02 and Sierra 18-3479 and includes all internal components so a single purchase typically covers a full water pump rebuild, making it a practical choice for routine maintenance or emergency repairs.

Key Features

• OEM compatibility: Comes as a direct replacement for Yamaha 6AH-W0078 variants and Sierra 18-3479, reducing the risk of fitment issues when swapped into the correct models.
• Complete kit: The package contains an impeller, housing, insert cup, plate, woodruff key, wear plate, water seal damper, O-ring, dowel pin and bolt so a full service can be performed without sourcing extra parts.
• Designed for Yamaha 4 Stroke: Specifically for Yamaha 4 Stroke 15HP and 20HP F15C and F20 outboards, which helps ensure correct operation for those engines when installed properly.
• Service convenience: Having the housing and internal components included means fewer service interruptions and a shorter repair time versus replacing individual parts one by one.
• Support available: The seller requests confirmation of compatibility and offers contact support if problems arise, which adds a layer of post-purchase assistance.

Who It's For

This kit is best for owners of Yamaha 4 Stroke outboards, specifically the F15C and F20 models, who need a full water pump overhaul with matched components. It is suitable for DIY mechanically inclined owners and small marine repair shops that prefer to replace the impeller and wear items in one service session.

Boat owners with different Yamaha models or uncertain OEM numbers should verify compatibility carefully before buying and may need a different kit. Those who prefer OEM-branded parts exclusively should also compare part numbers before committing.

Pros & Cons

Pros

• Complete replacement package reduces downtime by providing all necessary internal pump parts.
• Fits specified Yamaha 4 Stroke 15HP and 20HP models, which customers report as a good fit and functional replacement.
• Includes both the impeller and housing, avoiding the need to reuse worn components.

Cons

• Compatibility must be confirmed against OEM numbers before purchase, which adds a step for buyers with uncertain model years.

Specifications

Our Verdict

The Water Pump Impeller Kit is a practical, value-focused option for owners of Yamaha F15C and F20 4 Stroke outboards who want a full rebuild kit in one box. Because it replaces the OEM 6AH-W0078 series and includes the housing and seals, it reduces parts hunting and is good value for routine servicing or field repairs when compatibility is confirmed.

Frequently Asked Questions

Will this kit fit my F15C?
Check the engine's OEM number against 6AH-W0078-00/01/02; if it matches, this kit is intended to fit F15C models.

Does the package include the impeller housing?
Yes, the kit includes the water pump housing as well as the impeller and associated internal parts for a full service.

What if a part is missing or incorrect?
Contact the seller with compatibility details and they will respond to resolve problems as noted in the product listing.