Yamaha Thermostat for F2.5, F4, F4A, F6, F6A, F8, T8, F9.9, T9.9, F15, F25, T25, F30, F40, F40A, F50, T50, F60, T60, F70. Also used on F80 and F100 manufactured prior to 2000. This thermostat is also one of several thermostats on the XTO 425 and XTO 450.

Certain thermostats also require a gasket; it is recommended to always replace the gasket when you change the thermostat.