Not to my knowledge.
Gasoline only. No E15 either. I know it says right on that.
Actually, probably the best generators other than propane/natural gas would be a diesel powered unit like they use on construction sites. I know of someone who has one of those. Its 15000 watts. He has a 500 gallon fuel tank that gravity feeds it. He gets home delivery of the fuel just like a commercial business.
He said the former owner of the house had a construction business. So, he was already buying diesel by the tanker to run his dump trucks, excavators, and other heavy equipment.
The good thing about diesel is that it can sit in the tank for 6 months and it is not going to hurt it. All of the gasoline with ethanol in it causes long term storage problems. Especially in cold climate areas.
Here’s a site that offers kits allowing Hondas to run on propane or NG. But I’d run that by Honda to make sure.
http://www.propane-generators.com/honda-generators.php