6D3-12411-00-00 Thermostat 140°F for Yamaha 255 FSH Sport H 1800 2024-2026

Thermostat for Yamaha 255 FSH Sport H 1800

This 140°F thermostat for Yamaha replaces OEM part 6D3-12411-00-00 and regulates engine coolant temperature on 2024 through 2026 255 FSH Sport H 1800 boats.

Overview

This thermostat for Yamaha controls coolant flow so the 1800 engine reaches and holds its intended 140°F operating range. It is a direct replacement for OEM 6D3-12411-00-00 and suits owners maintaining or rebuilding the cooling system on the 255 FSH Sport H. The thermostat for Yamaha drops into the factory housing location without modification.

Built For Performance

• 140°F opening temperature matched to the 1800 engine cooling spec
• Cross-references OEM part 6D3-12411-00-00 for straightforward replacement
• Wax-pellet design opens and closes consistently across heat cycles
• Sealing flange controls coolant bypass for stable running temperature
• Built to withstand continuous marine coolant and corrosion exposure

Fits These Machines

• for Yamaha 255 FSH Sport H 1800, 2024-2026

On-The-Job Use

• Routine cooling system service and thermostat replacement
• Overheating diagnosis on the 1800 engine
• Winterization and spring recommissioning checks
• Rebuilds after impeller or coolant flow repairs

Specs At A Glance

Good To Know

Q: How do I know if my thermostat needs replacing? A: Slow warm-up, overheating, or erratic temperature readings on the 1800 often point to a stuck thermostat. Replacing it with the correct 140°F unit restores normal coolant regulation.

Q: Does this fit my exact model year? A: It is listed for the 255 FSH Sport H 1800 from 2024 to 2026 and cross-references 6D3-12411-00-00. Confirm your serial number and housing before ordering.

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