Yamaha EF2000iS Portable Inverter Generator uses a 79cc OHV 4-stroke engine that is gas powered and has a run time of about 10.5 hours. It features 1600 watt rated AC output and 2000 watt maximum AC output, and is equipped with an USFS-approved spark arrestor for super-quiet operational noise. It also provides better fuel usage with the smart Throttle that varies engine speed depending on the load. It is CARB Compliant and uses Inverter system with Pulse Width Modulation (PWM) control.