This manual covers the Yamaha F50 and F60 Four Stroke outboard motors manufactured between 2005 and 2009. These engines are engineered for reliable performance, featuring a 935 cc four-cylinder displacement and Electronic Fuel Injection (EFI) for efficient power delivery. The F50 model provides 50 horsepower, while the F60 model offers 60 horsepower, both equipped with a water-cooled system and a Power Trim and Tilt function. Their robust design and advanced technology make them suitable for a wide range of marine applications. The purpose of this Factory Service Manual is to provide comprehensive guidance for the maintenance, repair, and technical understanding of your Yamaha F50/F60 outboard motor. It details essential procedures, including lubrication, ignition system service, and fuel system requirements, along with specifications for oil types, capacities, spark plugs, and recommended fuel octane. This manual is an indispensable resource for owners, technicians, and mechanics seeking to ensure the optimal performance, longevity, and safe operation of these Yamaha marine engines.