The engineers at Yamaha looked at the total design and then made changes where they would be most effective — i.e., engine operating speed, intake noise, exhaust noise, and valvetrain noise. The most important addition is something they call "Economy Control”, which allows the engine speed to automatically change to match power demand. The EF2800i breaks new ground in the weight per output department, tipping the scales at just 29.1 kilos. It's the lightest generator in its class. The key is its multi-pole rotor with a small stator and Pulse Width Modulation inverter.