Yard Machine is a line of lawn equipment manufactured by MTD Products. The company makes push lawn mowers, riding lawn mowers, edgers and trimmers. The gas engines on some Yard Machine products have adjustable carburetors. If your mower idles too high or low, the carburetor can be adjusted by turning the idle adjustment screw on the back side of the engine. Adjusting the carburetor will take about 15 minutes.
Start the Yard Machine and allow it to run for six to eight minutes to warm up the engine. Turn off the engine after it has warmed up.
Insert the Phillips screwdriver into the Lawn Machine's idle adjustment screw which is on the bottom left side of the engine, near the air filter cover.
Turn the screw fully to the right until it stops. Don't twist too hard, as it can damage the screw.
Turn the screw a full turn to the left and start the machine again. Listen to engine run to determine if it sounds like it is running too high or too low.
Turn the screw a quarter turn to the right if the running speed seems slow and sluggish. Turn the screw a quarter turn to the left if the engine is running too high.