It's clean, it's quiet, and it's so flexible you can connect two EF2400iSs to make 4600 watts of power if you want to. One is all you need, though, for normal portable generator use. THis model uses Yamaha's powerful, 171cc overhead-valave engine, contains all the latest Yamaha inverter technology and puts out 2400 maximum watts of clean, pure power-in a package that weighs just 70 pounds. That makes it highly portable and the fact that it's super quiet makes the EF2400iS nice to use, too. Small but mighty, there's enough juice in here to crank up a high efficiency 13,500 BTU RV air conditioner.
View specs: http://www.yamahamotorsports.com/powerproducts/products/modelspecs/475/0/specs.aspx