Yamaha - Thermostat Cover 2 Cooling System Component 6DA-1241B-A0-9S. Overview. The Yamaha Thermostat Cover 2 6DA-1241B-A0-9S is designed to securely enclose and protect the thermostat within your engine's cooling system. This cover helps maintain proper sealing and pressure, ensuring coolant flows correctly and the engine operates at the right temperature. If the cover becomes cracked, warped, or improperly sealed, it can lead to coolant leaks or inconsistent temperature control. Replacing it helps keep your cooling system functioning efficiently and reliably.. Key Features. • Protective Thermostat Housing Cover - Secures and shields the thermostat for proper operation.. • OEM Fit Precision - Built to Yamaha specifications for accurate fit and dependable sealing.. • Maintains Cooling System Integrity - Helps regulate coolant flow and system pressure.. • Durable Construction - Designed to withstand heat, pressure, and marine conditions.. Engine & Boat Compatibility. Verify compatibilit