Yamaha - Thermostat - 6CE-12411-00-00 - F225 F250 F300 VF250Yamaha Thermostat Engine Cooling System Component F225 F250 F300 VF250 6CE 12411 00 00 Overview If you work around Yamaha outboards long enough, you learn that steady engine temperature makes a big difference in how a motor performs. The Yamaha Thermostat 6CE 12411 00 00 helps regulate coolant flow so the engine warms up properly and stays within its designed temperature range. It is a small component, but it plays an important role in keeping larger