Yamaha - Thermostat Gasket - Cooling System Seal - C55 E48 - 663-12414-A0-00

Overview

This is one of those small parts that can cause big cooling issues if it’s worn out or leaking. The Yamaha thermostat gasket helps keep a tight seal around the thermostat housing so your engine maintains proper temperature control. It’s a simple replacement, but it makes a real difference in keeping the cooling system working the way it should. When you’re servicing the thermostat, this is a part you always want to swap out.

Key Features

• Leak Prevention Seal – Creates a tight seal to prevent coolant or water leaks.

• Consistent Temperature Control – Helps maintain proper engine operating temperature.

• OEM Yamaha Fitment – Matches factory specs for accurate fit and reliable sealing.

• Durable Gasket Material – Built to handle heat cycles and marine conditions.

Engine & Boat Compatibility

• C55
• E48

FAQ

Q: What happens if a thermostat gasket fails?
A: You can get leaks around the housing, which may lead to poor cooling and inconsistent engine temperature.

Q: Should I replace the gasket when changing the thermostat?
A: Yes, it’s always best to install a new gasket to ensure a proper seal.

Q: Is sealant needed when installing this gasket?
A: In most cases no, but always check your service manual for your specific setup.

Q: Can this cause overheating if damaged?
A: It can contribute to cooling issues if it allows leaks or improper sealing.

• Supersessions
  663-12414-00-00
• Engine Application
  • C55
  • E48