To fix a lawn mower that is stalling during use, check the spark plug wire, replace the spark plug and clean the air screen and air filter. Drain and replace the fuel to ensure a contaminate is not causing the machine to stall, and then clean the blades thoroughly before using the lawn mower.
- Replace the spark plug and spark plug wire
The spark plug is typically located on the top or side of the machine. Remove the spark plug wire. Take the spark plug out with a wrench and install a new one. Replace the spark plug wire if it is cracked or visibly damaged.
- Clean the air screen and air filter
Locate the air screen and air filter using the owner's manual. Remove the air filter and wash it with clean water. Use a soft brush to remove debris from the air screen. Allow the air filter to dry thoroughly before replacing it.
- Drain and replace the fuel
Poor quality or contaminated fuel may cause the lawn mower to stall during use. Locate the main gas line and remove it, and then allow the fuel to drain into an approved container. Replace the gas line, and fill the mower with new fuel.