The owner's manual contains oil capacity information for Briggs & Stratton engines, and the company's website has an oil capacity chart that lists most engines. If the owner's manual can't be located or is damaged, replacement manuals can be downloaded, as well as the capacity chart, in Adobe PDF format.
The company recommends changing the oil after the first five hours of operation, for snow blowers and lawn mowers. All other Briggs & Stratton engines need the oil changed every 50 hours of operation or at the start of the usage season. Check the oil level with every usage to ensure it is not low or dirty.