OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Vanguard Twin B&S 14hp power loss

I think you are now a long way further ahead, Oluoot, and are headed in what is most likely the correct direction. You can get a free download of the B&S workshop manual for that engine here:
http://www.4shared.com/get/EUOFwobA/272144_Vanguard_Twin_Cylinder_.html

The illustrated parts list and operator's manual are also available as free downloads. Parts list:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6orvIVJ1DajI.pdf
Operator's manual:
http://bsintek.basco.com/BriggsDocumentDisplay/msvuAQ-K_ny7tH217FzoPu.pdf

Meanwhile there are literally dozens of internet discussions about blown Vanguard head gaskets you can find with a simple search. You might care to look at this one:
http://forums2.gardenweb.com/forums/load/tractor/msg1119005310306.html