Good article here on running a 16K BTU unit off a Honda EU2000.... Using various soft start methods (Supco and Dometic).
The Supco start capacitors are only $12 on Amazon, so simple and cheap enough to try out. I'm going to and test with my 2K watt portable gen. It should be all I need to run the 12K BTU Mermaid on my boat..
Honda eu2000i and air conditioning - Page 3 - SailNet Community