Gasoline left sitting in a vehicle will degrade, leaving behind a sticky varnish that clogs small passages inside carburetors and throttle bodies. Carburetor cleaner is a powerful blend of solvents designed to break down these deposits instantly. The spray blast physically washes away dirt, while the chemical solvents dissolve hard carbon crusts, gum, and lacquer.
Because the solvent is highly aggressive, avoid spraying it on plastic sensors, electrical wiring, or rubber gaskets, as it can melt or deform them. It also evaporates very quickly, leaving behind a clean, dry metal surface. Always work in a well-ventilated area and wear eye protection. The spray nozzle can easily blow back, and these solvents will cause severe stinging if they contact your eyes.