The Yamaha FZ (assuming you're referring to the FZ series bikes such as FZ-S, FZ-FI, etc.) typically requires around 1.2 liters of engine oil for an oil change. However, it's always best to consult the owner's manual of your specific Yamaha FZ model for the accurate oil capacity. The owner's manual provides the most reliable and precise information regarding maintenance procedures and oil specifications for your motorcycle.