Yamaha - Thermostat Cover - Cooling System Housing - 6AH-12413-00-1S

Overview

This is one of those parts that quietly keeps your cooling system sealed and working right. The thermostat cover holds everything in place and keeps water flowing where it needs to, without leaks or pressure loss. When it’s in good shape, you don’t think about it—but once it warps or corrodes, cooling issues can start showing up fast. It’s a simple piece, but it plays a big role in keeping your engine running at the right temperature.

Key Features

• Secure Thermostat Housing – Keeps the thermostat properly enclosed for consistent cooling operation.
• Leak-Resistant Fit – Designed to seal tightly and prevent water loss or pressure issues.
• OEM Fit and Alignment – Matches Yamaha specifications for proper installation and function.
• Marine-Ready Construction – Built to handle heat cycles and exposure to water environments.

Engine & Boat Compatibility

Designed for Yamaha outboard engines using this style of thermostat cover within the cooling system. Commonly used across modern Yamaha applications where proper temperature control is essential.

FAQ

Q: What are signs this cover needs to be replaced?
A: Leaks, corrosion, or visible warping are the most common signs.

Q: Can a bad cover cause overheating?
A: Yes, if it doesn’t seal properly, it can affect water flow and cooling efficiency.

Q: Should I replace the gasket when installing this?
A: Yes, always use a new gasket to ensure a proper seal.

Q: Does saltwater affect this part?
A: Over time, yes. Corrosion can build up if it’s not maintained and rinsed regularly.

Q: Is installation difficult?
A: It’s usually straightforward, especially if you already have access to the thermostat housing.