1. Locate the carburetor. The carburetor is usually located on the side of the engine, near the air filter. It is a small, metal device with a fuel line attached to it.
2. Remove the air filter cover. The air filter cover is usually held in place by a few screws. Once the cover is removed, you will be able to see the carburetor.
3. Locate the idle adjustment screw. The idle adjustment screw is usually located on the side of the carburetor. It is a small, brass screw with a spring around it.
4. Turn the idle adjustment screw clockwise to increase the idle speed. Turn the screw counterclockwise to decrease the idle speed.
5. Start the lawn mower and let it run for a few minutes. This will allow the carburetor to adjust to the new settings.
6. Check the idle speed. The idle speed should be set so that the engine runs smoothly without stalling. If the engine is idling too fast, turn the idle adjustment screw clockwise to decrease the speed. If the engine is idling too slowly, turn the idle adjustment screw counterclockwise to increase the speed.
7. Replace the air filter cover.
Note: Always refer to the lawn mower's owner's manual for specific instructions on how to adjust the carburetor.
