Generator maintenance consists of the regular service tasks required to keep a generator reliable and extend its service life. A well-maintained generator starts when needed and delivers rated power. Neglected Generators fail at the moment they are most needed. Maintenance intervals are expressed in operating hours or calendar time, whichever comes first.
Engine oil is changed every 50 to 100 operating hours for small gasoline generators, or annually if that limit is not reached. The oil type is specified in the owner's manual, typically 10W-30 for most small engines. High-mileage or synthetic oils are used for generators operated under heavy load. The oil level is checked before each use, and the oil is changed more frequently in dusty conditions.
The air filter is cleaned or replaced every 50 to 100 operating hours. A clogged air filter restricts airflow, reducing power and increasing fuel consumption. Paper filters are replaced; foam filters are washed with soapy water, dried, and oiled. The fuel filter is replaced annually or every 200 hours. Water and sediment in the fuel tank are drained periodically.
Gasoline stored for more than 30 days is treated with a fuel stabilizer. The carburetor is drained or run dry before long-term storage to prevent varnish buildup. Ethanol-blended gasoline attracts moisture and degrades faster than pure gasoline. In areas where ethanol-free fuel is available, it is preferred for generator storage.
Generators are stored in a dry, ventilated building, not in the living space. The generator is run under load for 30 minutes every month to keep the engine lubricated and prevent moisture accumulation. The battery on electric-start generators is kept charged with a maintenance charger. The transfer switch is tested annually by simulating a power outage.