What was found
(CAN) DURING TROUBLESHOOTING FOR AN ENGINE OIL LEAK, IT WAS DETERMINED THAT OIL WAS SEEPING OUT THE CENTER THROUGH-BOLT STUDS; ENGINE AND CRANKCASE WAS DISASSEMBLED FOR ACCESS TO THE THROUGH-STUD O-RINGS. IT WAS THEN DISCOVERED THAT THE WRONG O-RINGS WERE INSTALLED ON THE 6 THROUGH-STUDS. THE O-RINGS WERE THICKER THAN THE RECESS WAS GROOVED OUT FOR AND AS A RESULT THE 6 O-RINGS WERE SQUASHED AND STUCK IN THE MATING SURFACES OF THE CRANKCASE HALVES, WHICH RESULTED IN A LOSS OF TORQUE AND FRETTING OF THE CRANKCASE MATING SURFACES. THE CRANKCASE HALVES NEEDED TO BE MILLED AND LINE BORED.