Yamaha XF450XSA Outboard Motor. 25-Inch Shaft 5.6-Liter V8 Digital Electronic Control Electronic Fuel Injection Electric Start Power Trim and Tilt Gray. The Yamaha XF450XSA is Yamaha's flagship 450-horsepower V8 outboard, delivering unmatched offshore performance for the largest and most demanding boats. With its massive 5.6-liter displacement, this outboard is engineered for ultimate torque, acceleration, and top-end power. The XF450XSA sets a new standard for offshore reliability and precision