I've got an 18.5 hp Briggs $ Stratton ELS500 Series motor that is blowing oil out the exhaust. Is this most likely a head gasket blown? Any suggestions would be appreciated. Thanks in advance!
unless you have tipped the mower on the side or the carb has leaked fuel into the oil then yes gasket time.
Check the oil level if it is too high and smells of fuel then you have a carb problem and perhaps a blown gasket as well