6D3-12411-00-00 Thermostat 140°F for Yamaha FX HO 1800 2009-2023

Thermostat for Yamaha FX HO 1800

This replacement thermostat for Yamaha FX HO 1800 watercraft regulates engine coolant flow at 140°F, referencing OEM part 6D3-12411-00-00.

Overview

This thermostat for Yamaha FX HO 1800 keeps the 1800cc engine operating within its proper temperature range by opening and closing coolant flow as conditions change. Built as a direct-fit replacement for the 140°F rating, it serves riders performing routine cooling system maintenance or replacing a stuck or worn thermostat. It is intended for Yamaha FX HO 1800 models from 2009 through 2023.

Built For Performance

• 140°F opening temperature matches the factory specification for consistent engine warm-up
• Direct-fit replacement referencing OEM part 6D3-12411-00-00
• Construction suited to the demands of marine cooling systems
• Helps maintain stable operating temperatures under load
• Designed for routine replacement and cooling system service

Fits These Machines

• for Yamaha FX HO 1800, 2009-2023

On-The-Job Use

• Routine cooling system maintenance on personal watercraft
• Replacing a thermostat stuck open or closed
• Engine temperature troubleshooting and repair
• Service after flushing or rebuilding the cooling system

Specs At A Glance

Good To Know

Q: How do I know if my thermostat needs replacing? A: Common signs include an engine that runs cold, overheats, or fluctuates in temperature. A stuck thermostat should be replaced to protect the engine.

Q: Does this thermostat come with a gasket? A: This listing covers the thermostat itself. Check your service manual for gasket and housing requirements before installation.

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