Gumout Carb / Choke and Parts Cleaner quickly removes deposits from the inside and outside of the carburetor to improve engine performance and fuel economy. Over time, carburetors and choke valves can become clogged with gum, varnish, and dirt, affecting performance. Gumout Carb and Choke Cleaner cleans carburetors, linkage, choke valves, and unpainted metal parts to improve performance and reduce emissions.