Yamaha XF450USA Outboard Motor. 30-Inch Shaft 5.6-Liter V8 Digital Electronic Control Electronic Fuel Injection Electric Start Power Trim and Tilt Gray. The Yamaha XF450USA is the 30-inch shaft version of Yamaha's most powerful outboard - the 450-horsepower 5.6-liter V8. Designed for offshore boats with deeper transoms, this model provides unmatched horsepower, torque, and reliability. Whether powering a large center console, offshore fishing boat, or luxury vessel, the XF450USA delivers command