Small Engines (Lawn Mowers, etc.): briggs 8 hp snowblower, valve carburetor, wire tie

Question
oil is grey colored creamy leking out the OHV overflow valve

Answer
carburetor is overflowing.  Remove take apart and clean all air and fuel passages with a wire from a wire tie.  Blow out with carburetor cleaner or compressed aid.  Reassemble with new carburetor kit and mount using new mounting gaskets.  If it has a fuel filter change it.  If not clean the filter in the bottom of the tank.  Change the oil, fill with fresh gas and it should be set to go.