A. Small lightweight generator companies do not always have the same reliability and their rated peak output is sometimes inaccurate. The industry standard is the Honda eu2000i and their latest eu2200i. These generate continuous rated power to start and run a rooftop AC unit with SoftStartRV™. Other generators also produce good quality results. Looks for generators with motors over 90cc as the preferred choice for dependable operation. Smaller generators, with 79cc motors, can also be utilized with 13.5 KBTU air conditioners and smaller as long as all other loads are off and the elevation is not too high. All generators are not created equally or even rated equally. Googling research before deciding on your generator will make you a smart buyer. How you will use the generator is also important. Some of the above-mentioned generators are working above their 13.3-amp rating to run an air conditioner. Don’t expect to add any other loads to a single generator while the air conditioner is running unless you have allowed for it in sizing your generator. Essentially you need to practice smart power management. Reduce the generator load by turning of the refrigerator and battery charger, Since air gets thinner the higher you go, elevation also affects the generator. Small generators may not have enough power at higher elevations to keep your A/C running, even though SoftStartRV has been able to start it. Engines lose about 3.5% of their power per 1000-foot rise in elevation. You may also need to re-jet the carburetor to get the generator motor to produce enough power since the thin air makes the mixture too rich. There are cases where you may need a 3 KW generator or larger to run an air conditioner in the high desert. Careful planning and generator selection are the keys to success. Be aware that running at lower elevations again will require the jet change again or you risk high combustion temperatures and burned engine components. Honda makes high elevation kits for its generator and some Yamaha dealers can also provide jets for those generators.