Yamaha - Water Seal Rubber - Cooling System Seal - 63V-44368-00-00

Overview

This is one of those small parts that can cause big cooling problems if it’s not sealing right. I’ve seen engines overheat just because a worn rubber seal let water escape instead of moving where it should. This piece helps keep the water flow tight and directed through the system. When it’s in good shape, you don’t think about it—but it’s doing a lot behind the scenes.

Key Features

• Secure Water Seal – Helps prevent water loss within the cooling system.
• OEM Fitment – Designed to match Yamaha specifications for proper sealing and placement.
• Flexible Rubber Construction – Maintains sealing ability under heat and pressure changes.
• Supports Cooling Efficiency – Keeps water flow directed for consistent engine temperature.

Engine & Boat Compatibility

Fits Yamaha outboard engines equipped with compatible water pump and cooling system assemblies. Commonly used on small- to mid-range horsepower outboards across fishing boats, tenders, and recreational vessels.

FAQ

Q: What happens if this water seal is worn out?
A: Water can leak or lose pressure, leading to poor cooling and possible overheating.

Q: Should I replace this during water pump service?
A: Yes, it’s a good idea to replace it while everything is apart to ensure a proper seal.

Q: Can this seal cause overheating issues?
A: Definitely—if it’s not sealing correctly, the cooling system won’t function properly.

Q: How does saltwater affect this rubber seal?
A: Over time, salt can cause the rubber to harden or degrade if not maintained.

Q: Is installation difficult?
A: It’s straightforward, just make sure it’s seated properly for a tight seal.

• Supersessions
  63V-44368-01-00, 63V-44368-01-00