What was found
EN-ROUTE FROM KBUF TO KROC AT 7000’ MSL THE PILOT OBSERVED THE MASTER CAUTION LIGHT ILLUMINATE & THE RT ENG SUFFERED A COMPLETE LOSS OF POWER RESULTING IN THE AUTO FEATHER SYS ENGAGING. THE PILOT FOLLOWED THE ENG FAILURE CHECKLIST & SECURED THE RT ENG. THE PILOT DECLARED AN EMERGENCY & RETURNED TO KBUF, LANDED WITHOUT INCIDENT. INSPECTION OF RT ENG REVEALED THE THREADS ON THE MOUNTING STUD & CAP NUT THAT ATTACH THE LOW PRESS FUEL FILTER HOUSING WERE STRIPPED CAUSING THE FUEL FILTER HOUSING TO SEPARATE REDUCING FUEL FLOW TO RT ENG. R & R THE ATTACHMENT STUD & NUT CAP IAW MM 28-00-00.