Yamaha - Thermostat - Engine Cooling - F300 F350 (V8) - 6AW-12411-00-00

Overview

On large Yamaha offshore motors, temperature control is critical for keeping the engine running smoothly under heavy load. The Yamaha 6AW-12411-00-00 Thermostat helps regulate coolant flow so the engine warms up properly and maintains a stable operating temperature. When thermostats wear out or stick, engines can run too cold or start running hotter than they should. Replacing this part during regular cooling system service helps keep big horsepower Yamaha outboards performing reliably whether you're cruising offshore or running long distances.

Key Features

• Accurate Temperature Control – Regulates coolant flow to maintain proper engine operating temperature.

• OEM Yamaha Engineering – Built to Yamaha factory specifications for dependable performance and proper fit.

• Supports Engine Efficiency – Helps the engine reach and maintain optimal operating conditions.

• Important Preventative Maintenance Part – Often replaced during cooling system service or water pump maintenance.

Engine & Boat Compatibility

• F300 - 2007-2009
• F350 - 2007-Current
• FL350 - 2010
• LF300 - 2007-2009
• LF350 - 2007-Current

FAQ

Q: What happens if a thermostat sticks closed on a Yamaha outboard?
A: The engine may overheat because coolant cannot circulate properly through the cooling system.

Q: Can a thermostat cause an engine to run too cool?
A: Yes. If the thermostat sticks open, the engine may never reach its proper operating temperature.

Q: How often should thermostats be replaced on larger Yamaha outboards?
A: Many technicians recommend inspecting or replacing them every couple of seasons as part of routine cooling system service.

Q: Does saltwater use affect thermostat life?
A: Salt buildup and mineral deposits can shorten thermostat life if the engine is not flushed regularly.

Q: Is thermostat replacement typically done with other cooling system service?
A: Yes. It is commonly replaced during water pump service or other cooling system maintenance.

• Engine Application
  • F300 - 2007-2009
  • F350 - 2007-Current
  • FL350 - 2010
  • LF300 - 2007-2009
  • LF350 - 2007-Current