Roger good post. Isn't there an awful lot of oil on the outsides of that unit? In the picture with the lines into the gas tank it is pretty oily. Looks like the kind of blow out you get when one of those two carb gaskets are bad. The ones between the filter housing and carb or the carb and the head gasket. Stihl don't have breather like Echo that leak do they?
I was told that gu is the by-product of corn gas eating up the plastics in the gas tank and delivery system. Never seen quite that much but have seem
somethign similar on several machines. On Echo those gas tank groments are getting ate up from inside.