What is function of this Device in 2T outboard engines, like 15hp Yamaha, Suzuki, Honda and Tohatsu?

This Device like heater or thermostat taken out in 8hp 2t Tohatsu outboard engine. What is function of this Device in 2T outboard engines, like 15hp Yamaha, Suzuki, Honda and Tohatsu

That is a thermostat, it opens when engine is warmed up to correct operating temperature

That is a thermostat.