Carburetor Cleaner: Engine should be turned off and air cleaner removed. Now, start engine and attach extension tube to valve button so that all parts of the carburetor can be reached. Spray liberally. Adjust air-fuel mixture. Finish up by cleaning outside of carburetor.Automatic Choke Cleaner: Remove air cleaner. While choke is being opened and closed by hand, spray both ends of choke valve. Remove choke cover and then start engine. Spray vacuum cylinder.Clean PCV Systems: While motor running, spray PCV valve and line. While motor is still running, remove oil filter cap and spray into crankcase for about 10 seconds.Free Up Heat Risers: Engine must be cold. Spray heater valve shaft ends. Permit time to penetrate (a few seconds), then move counterweights up and down.Clean Carburetor Linkage: Merely spray carburetor linkage until clean.