The process of removing carbon buildup from engine and exhaust components. These parts include but are not limited to the piston, the combustion chamber, valves (four-stroke engine), power-valve (two-stroke engine), exhaust pipe and silencer. If carbon is allowed to accumulate it can raise engine compression and engine temperatures, cause component damage and reduce engine performance. Excess carbon build-up can produce hot-spots on a piston leading to detonation and pre-ignition – both of which are detrimental in a gasoline powered engine. On two stroke engines, carbon buildup can restrict the exhaust port volume and reduce performance. The process of de-carbonizing an engine is also called de-coking the engine. Methods for decarbonizing an engine include but are not limited to scraping carbon from the engine parts with a plastic knife, using an abrasive cleaning pad, steel wool, emery cloth and or chemical cleaners.