Yamaha Thermostat Seal 705-12412-00-00. Overview. The Yamaha Thermostat Seal 705-12412-00-00 is a genuine original equipment manufacturer component designed to create a secure seal between the thermostat and its housing. This essential part helps prevent coolant leaks and ensures proper temperature regulation within your engine's cooling system.. Manufactured to Yamaha's exact specifications, this seal provides a precise fit and dependable performance. It is an ideal replacement for worn or degr