Spark plug replacement depends on various factors, such as environment, usage, and the quality of the spark plugs. However, as a general rule, replacing the spark plugs every 100 to 150 hours of operation or annually, whichever comes first, is recommended. It’s also a good idea to periodically inspect the spark plugs for signs of wear, such as contaminated or damaged electrodes, and replace them if necessary. Regular maintenance helps keep your generator running efficiently and prolongs its life. It is also essential to use high-quality spark plugs designed for your generator’s specific make and model to ensure optimum performance.