great you found it . never seen one blown before but almost any other problem you might name hahaha . probably just bad assembling in china . just have a good looksee a straight edge across it and a good laping on a good flat surface normally does the trick . migth have just been loose from factory it doesnt look lke its done too much work .
good luck with it mate . had a few late model briggs' with that problem but all 4 were just loose and blew the gaskets cleaned up and back together , no problems again
