This powerful combination of concentrated solvents is specially formulated to remove dirt, gum and varnish deposits that ten to build up on the moving and sealing surfaces of engine carburetors, heat valves and automatic chokes, throttle bodies, PCV valves and linkages. Our product helps to free sticky valves, stuck heat risers and throttle linkages. No lear or silicone. Will not harm oxygen sensors, catalytic converters or fuel injectors. Periodic use on cars, trucks, airplanes, boats, lawnmowers, etc., will keep engines clean, fuel efficient and trouble free. This cleaner can even be used on running engines. This product is formulated for high performance without the use of ozone depleting chlorinated solvents.