This procedure can be used to pull contaminates out of a carburetor where other methods have failed. It uses the working compression of a running engine as a vacuum to suction any remaining blockage from the jets. Use this method secondary to an actual carburetor cleaning. This is most useful when compressed air is not an available resource. Begin by starting the engine and block the intake. Then release the block before the engine suffocates. Immediately after releasing the thumb or other instrument the suffocating, the engine's governor will respond by opening to a full throttle. At the peak of full throttle, repeat blocking the intake. By blocking the incoming air and removing it just before the engine dies out, fuel is forced with pressure through the carburetor, opening varnished passageways. This action is similar to plunging a toilet during a flush.