The YG is considered the industrial version. Features mentioned below.
The EF is considered the generator style for recreational and home use applications.
Ground Fault Protection
All YG units have ground fault circuit protection "GFI" on the 2 straight blade receptacles OSHA approved.
The EF12000 is the only EF unit offered with a GFI
Frame
The YG has a heavy-duty frame with lift eye to offer the maximum protection for the generator.
The EF has a "Standard" frame. No lift eye.
Start Switch
The YG Unit has a push button start switch.
The EF unit has a key switch.
Warranty
The YG unit has a one-year warranty for industrial use.
The EF unit has a two-year warranty for home owner use. This warranty is adjusted to only a six-month (180 days) warranty period when used in an industrial application.