I purchase a Kohler 14Kw generator only to be told by my utility they do not and can not provide the required 5-11 inch WC for NG.First,I made the mistake of not reading specs on required NG gas preasue required. I did how ever ask a number of plumbers and the sales people about this.I also contacted the Gas Utility but by time they got back to me I had the Gen in my yard. No one warned me cause no one knows the answer. Now I call Electric supply house where the unit was purchased and their answer was to install propane.They will not take it back. Next I call Kolher customer service who refers me back to where I purchased the unit. I explain that has been done and they do not have answers. Kohler dose not have a Tech or Enginnering service to speak with as a unit owner. They may for the Authorized Reps,don`t know. I hear these are good units but do your homework because if you need it their customer service sucks.