hello, I would wait just before grass starts growing. Its pretty simple, with a new spark plug and an oil change is good. oil the air filter too. I recommended putting all fresh gas in your mower every spring, for easy starting. In the winter, Stable is a good brand to run through the carb just before putting it away. Also a blade sharpening is a good thing. If all this is done every season it should last a long time. Oh i almost forgot, make sure to check fuel lines before adding gas. Cheers