Yamaha Cooling Fan Assembly YFG-31020-23-20. Overview. The Yamaha YFG-31020-23-20 Cooling Fan Assembly is a genuine original equipment manufacturer component designed to help regulate engine temperature by promoting consistent airflow through the cooling system. Cooling fans play an important role in maintaining safe operating temperatures by assisting in the dissipation of heat generated during engine operation.. A properly functioning cooling fan assembly helps protect engine components from o