6D3-12411-00-00 Thermostat 140°F for Yamaha 212 1800 2020-2022

Thermostat for Yamaha 212 1800

This engine thermostat for Yamaha 212 1800 boats regulates coolant flow to keep operating temperature steady, and it carries the OEM cross-reference 6D3-12411-00-00 with a 140°F rating.

Overview

This thermostat for Yamaha 212 1800 boats is a replacement temperature control valve that opens and closes with coolant heat to hold the engine at its designed operating range. Built to the 140°F rating and 6D3-12411-00-00 reference, it suits boat owners performing routine cooling system service. Installing a fresh thermostat for Yamaha 212 1800 applications helps restore consistent warm-up and stable running temperatures.

Built For Performance

• 140°F opening temperature matches the factory specification for these engine families
• OEM cross-reference 6D3-12411-00-00 for straightforward parts matching
• Wax-pellet design responds smoothly as coolant temperature rises
• Sealing flange seats against the housing to limit bypass flow
• Construction suited to closed-loop marine cooling systems

Fits These Machines

• for Yamaha 212 1800, 2020-2022

On-The-Job Use

• Routine cooling system refresh on 2020-2022 Yamaha 212 1800 boats
• Replacing a thermostat stuck open that keeps the engine running cold
• Replacing a thermostat stuck closed that causes overheating
• Seasonal maintenance before launching for the summer

Specs At A Glance

Good To Know

Q: How do I know if my thermostat has failed? A: An engine that never reaches normal temperature or one that overheats quickly can both point to a stuck thermostat. Testing it in heated water shows whether it opens near 140°F.

Q: Should I replace the gasket at the same time? A: Yes, the housing gasket or seal should be renewed whenever the thermostat is swapped to prevent coolant leaks. Inspect the housing for corrosion while it is open.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.