Yamaha - Water Pump Repair Kit - Cooling System Service - 6H4-W0078-A0-00

Overview

If you’ve run Yamahas long enough, you know the water pump is one of those things you don’t ignore. This kit is what you reach for when your telltale stream weakens or you’re doing preventative maintenance before it becomes a problem. It’s built to bring your cooling system back to proper flow and keep your motor running at the temperature it was designed for. Whether you're in salt or fresh water, this is a routine job that pays off every time you turn the key.

Key Features

• Complete Service Kit – Includes the essential components needed to restore proper water pump function in one job.
• Reliable Cooling Performance – Helps maintain steady water flow to protect your engine from overheating.
• OEM Fit and Seal – Designed to match Yamaha factory specs for proper alignment and sealing.
• Durable Internal Components – Built to handle continuous use in both freshwater and saltwater conditions.
• Routine Maintenance Ready – Ideal for scheduled service intervals to avoid unexpected failures on the water.

Engine & Boat Compatibility

Designed for Yamaha outboards using compatible water pump assemblies. Suitable for a wide range of mid-size outboard engines commonly found on fishing boats, skiffs, and small recreational vessels. Always confirm fitment with your specific model before installation.

FAQ

Q: What are signs my water pump needs to be replaced?
A: Weak or inconsistent water stream, overheating alarms, or higher-than-normal engine temps are common signs.

Q: How often should I replace this kit?
A: Most boaters replace it every 1–2 seasons, especially if running in saltwater or sandy areas.

Q: Can I install this myself?
A: Yes, if you’re comfortable dropping the lower unit and following torque specs. Otherwise, a shop can handle it quickly.

Q: Does saltwater use affect lifespan?
A: Definitely. Salt and debris wear components faster, so more frequent inspections and replacements are recommended.

Q: Should I replace the whole kit or just the impeller?
A: It’s best to replace the full kit to ensure all sealing surfaces and wear parts are refreshed at the same time.

• Supersessions
  6H4-W0078-01-00, 6H4-W0078-00-00