Yamaha - Thermostat Cover Cooling System Housing 6EK-12413-00-00. Overview. Thermostat covers are one of those parts you usually only deal with when you're already into the cooling system. But if it's cracked, corroded, or not sealing right, it can cause more problems than you'd expect. I've seen small leaks or poor sealing turn into overheating issues pretty quickly. When this piece is solid and sealed up properly, the cooling system just does its job without any drama.. Key Features. • Secure Thermostat Housing - Encloses and protects the thermostat within the cooling system.• Leak-Resistant Sealing Surface - Designed to work with gaskets for tight, reliable sealing.• Durable Marine Construction - Built to withstand heat cycles and constant water exposure.• Corrosion-Resistant Design - Helps hold up against harsh saltwater environments.• Direct Fit Replacement - Matches Yamaha specifications for proper alignment and installation.. Engine & Boat Compatibility. Designed for Yamaha outb