Maximum overall performance: Microcomputer Ignition adjusts timing to maintain optimum engine performance, economy and power under all conditions. (F8 and up) Ultra-low emissions: Yamaha jet drive four strokes are California Air Resources Board (C.A.R.B.) Three-Star Rated for Ultra-Low Emissions and meet all federal EPA requirements. When you need to get to where a prop won't take you, get an F90 Jet Drive. This 65hp engine is a marine-inspired 4-stroke that's as much as 50% quieter than a conventional 2-stroke, and up to 30% more fuel efficient, too. When you need to explore the shallow stuff, the F60 Jet Drive (40hp) is the perfect midrange outboard. It's power-packed, compact, quiet, lightweight, and efficient - as much as 30% more fuel-efficient than a conventional 2-stroke. SEE ALL FEATURES AND BENEFITS Compare models See full specification