KUNOANZ Water Pump Impeller Kit for Yamaha 9.9/15 HP 2- & 4-Stroke (63V-W0078) — Rubber Impeller & Seal Kit

KUNOANZ 63V-W0078-01-00 is a replacement water pump impeller kit engineered to fit Yamaha 9.9 and 15 HP 2- and 4-stroke outboards (1996–2024), restoring cooling flow with OEM-compatible parts.

When an outboard’s cooling system shows signs of reduced flow, overheating, or visible impeller damage, replacing the impeller and seal kit is a common maintenance step. This KUNOANZ kit corresponds to Yamaha OEM numbers 63V-W0078-00-00/01-00 and fits many Sierra and aftermarket cross-references. The components are molded from durable rubber designed for repeated freshwater and saltwater immersion, and the kit targets 2-cylinder 9.9 and 15 HP engines produced across multiple model years.

How do I know this kit fits my Yamaha outboard?

Confirm fitment by checking the engine nameplate and comparing OEM part numbers. This KUNOANZ kit replaces Yamaha references 63V-W0078-00-00, 63V-W0078-01-00 and similar numbers used by Sierra and Mallory, so matching those codes ensures compatibility.

• Fits Yamaha 9.9 and 15 HP 2/4-stroke, 2-cylinder models (1996–2024)
• Replaces OEM 63V-W0078-00-00, 63V-W0078-01-00, 63V-44301-00-00
• Cross-references Sierra 18-3410 / 18-3412 and Mallory 9-48609 / 9-48617

What parts are included and what materials are used?

The kit typically contains the impeller, gaskets, O-rings and a faceplate or seal components needed for a single repair, made to match original dimensions. Materials focus on marine-grade rubber for the impeller and corrosion-resistant seals to handle prolonged exposure to water.

• High-quality rubber impeller molded for flexibility and wear resistance
• Gaskets and O-rings sized to OEM specifications for leak prevention
• Hardware and backing components to restore proper pump clearance

How difficult is installation and what tools will I need?

Replacement is a routine boat-maintenance job for someone comfortable with basic mechanical tasks. Access to the lower unit and common hand tools is required; some models need the propeller removed and the water pump housing exposed.

• Basic tools: socket set, screwdrivers, pliers and marine grease
• Optional: impeller puller or alignment tool depending on model
• Service manual recommended for torque specs and clearance checks

What performance benefits should I expect after replacing the impeller?

A properly installed impeller restores designed coolant flow, which helps maintain normal engine operating temperatures and prevents premature wear caused by overheating. It also reduces the risk of cavitation and ensures consistent water pressure through the cooling passages.

• Restores manufacturer-level cooling flow for engine protection
• Reduces overheating risk when installed correctly
• Improves water pump reliability between regular maintenance intervals

Who is this for: This KUNOANZ impeller kit is aimed at boat owners, marine mechanics and DIY enthusiasts who run Yamaha 9.9 or 15 HP outboards and need a reliable, OEM-compatible replacement. If you perform routine seasonal maintenance, repair a water pump showing reduced flow, or are preparing a vessel for extended use, this kit supplies the core components to return the lower-unit cooling system to serviceable condition. Always verify the engine nameplate and part numbers before purchase to avoid incorrect fitment.