Any internal combustion engine needs the right air-to-fuel mixture to work properly, and that function is handled by the engine’s carburetor. One sign that your Tecumseh engine is not getting the right air-to-fuel mixture is when the engine dies out during the idle state. There are many reasons why an engine wouldn't idle properly, such as a plugged engine air filter or a fuel pickup that's restricted by gummy gas in the carburetor. Check the carburetor’s idle adjustment screw first, before delving deeper into the problem.
Check Idle Adjustment Screw
Locate the engine’s carburetor. The carburetor is usually located near the engine’s fuel tank.
Locate the idle adjustment screw on the carburetor. The idle adjustment screw has a screw with a slot for a flat head screwdriver, and is usually located higher than the main adjustment screw of the carburetor.
Start the engine and hold the throttle to prevent the engine from dying out. Allow the engine to run for 2 to 5 minutes for the engine to reach the normal operating temperature.
Release the engine’s throttle and adjust the idle adjustment screw either clockwise or counterclockwise until the engine’s idle is running smoothly.
Replace the Air Filter
Remove the air filter cover on the side of the Tecumseh engine by unscrewing the single screw that holds it in place with the flat head screwdriver.
Pull the cover off to reveal the air filter.
Pull the dirty old air filter out and replace it with a new one so air can flow freely into the gas mixture in the carburetor.
Tighten the air filter cover back into place.
Clean the Carburetor
Remove the screw under the carburetor holding the fuel bowl in place, using a flat head screwdriver.
Pull the fuel bowl off the base of the carburetor.
Direct the carburetor cleaner spray into the fuel bowl and onto the carburetor intake valves located above the float that hangs into the fuel bowl. The carburetor cleaner will remove the old gummy gas and allow fuel to easily flow into the piston chamber.
Replace the fuel bowl and tighten it into place.