Gumout Small Engine Carb / Choke Cleaner quickly removes deposits from the inside and outside of the carburetor to improve engine performance and fuel economy. Carburetors and choke valves in small engines are especially prone to gum, varnish, and dirt buildup because of less frequent use. Gumout Carb and Choke Cleaner cleans carburetors, linkage, and choke valves to improve performance and reduce emissions.