A pair of 2000 watt Hondas or a pair of 2000 watt Yamahas hooked together works well because they are lightweight and supply enough power for a 15,000 BTU A/C. Whenever you don’t need the A/C, then one will run things very economically. However, their run-times are rather short under full load. The Honda has a fuel pump so a practical extended run-time modification is easy and some have luck with the Yamaha extended run-time as modifications as well. The Yamaha doesn’t have a fuel pump so its setup is a little fussier. Neither has an electric start but they pull-start easily.
Engine generators can’t supply as much power at altitude as they can at sea level. Both Honda and Yamaha say their regular 3000 watt inverter generators (EU3000is and EF3000iSE) will run a 13,500 BTU A/C but they don’t claim to run a 15,000 BTU A/C unit. If your E/G size is marginal then you might have problems at higher altitudes or on A/C restart after a short period off. The Yamaha EF3000iSEB generator, at 136 pounds dry weight, uses its starting battery to supply extra “boost” for starting A/C units with up to 3500 short-term watts of power and will supply an A/C with many hours of power on a single tank of fuel.
There are very few complaints about the Honda or Yamaha generators but several members have voiced success with other brands.
Good luck with your research.
2015 Wildcat 282 RKX
2011 F350 Lariat, 6.7 L. Diesel, 8 ft., SRW, Reese R20