The four-cylinder Double Overhead Cam engine gives you power rivaling a two-stroke V6, and works in tandem with the brains of our advanced microprocessor ECM (Engine Control Module) to give you precision Electronic Fuel Injection based on engine load and speed. As a result, you get the speed and strength of a V6 two-stroke, but with the characteristics of a four-stroke: whisper-quiet operation, remarkable fuel efficiency, and emissions so low, the F150 meets CARB 2006 three-star requirements. Powerful, efficient, versatile and affordable. It's everything you could ask for in an outboard. It's a Yamaha.