Genuine Yamaha Thermostat
 
The Yamaha 66M-12411-01 thermostat is a genuine Yamaha four-stroke outboard thermostat, rated at approximately 60°C. It fits a range of smaller and mid-range Yamaha outboard engines, generally from 2.5 hp up to 70 hp, with some older 80 hp and 100 hp models also listed. Exact compatibility depends on the engine's model code and year.
 
Yamaha models it fits
The commonly listed compatible models include:
2.5–6 hp: F2.5, F4A, F4B, F5A, F6A, F6B, F6C and F6D.
8–9.9 hp: F8A, F8B, F8C, F9.9A, F9.9B, F9.9C, F9.9F and F9.9J.
15–25 hp: F15A, F20A, F25A, F25D, FT25B and FT25F.
30–40 hp: F30A, F30B, F40A, F40B and F40F.
50–70 hp: F50A, F50F, F50H, F60A, F60C, F60F and F70A.
Related high-thrust models include T8, FT8D, FT9.9D, FT9.9G, FT9.9L, FT50 and FT60 variants.
 
Some parts catalogues also list the F80A and F100A from 1999–2000, as well as certain later F70 variants. These should be checked against the engine's serial number before ordering.
 
To confirm the exact fit: please get in touch with your model and serial numbers