On most generators, maintenance is necessary but not difficult. Every generator includes an owner’s manual with a maintenance schedule and instructions. Typical maintenance includes checking and changing oil, fuel filters, and air filters. Less-frequent maintenance includes adjusting valves and changing spark plugs and coolant.
Nearly all generators include an automatic shutoff switch, which activates if the oil level drops too low. Additional safety features designed to protect the generator are included on better quality units. These may include overtemperature/overload, overcrank (cranking an already-running engine), and over/under voltage and frequency. Some units use a digital controller capable of alerting about a variety of faults.
As you select your generator, be sure to read the fine print of the warranty. The best standard warranties I have seen are for a period of two or more years (with extensions available at extra cost), cover parts and labor, do not exclude off-grid applications, and are transferable. A few include on-site service. Some warranties are voided if gasoline engines are converted to LPG while others allow the aftermarket conversion.