Be sure to use the correct type of gasoline for your lawn mower. Most lawn mowers require unleaded gasoline with an octane rating of 87 or higher. Do not use gasoline that contains ethanol, as this can damage the engine of your lawn mower.
To add gasoline to your lawn mower, open the fuel tank and insert the funnel into the tank. Be careful not to overfill the tank, as this can also damage the engine. Once the tank is full, replace the fuel tank cap and start the lawn mower.