Auxiliary engine decarbonised. Piston rings for all units replaced. Piston pin bearing & new bottom end bolt were used. Oil cooler was drained & cleaned both oil side and SW side. All main bearing inspected. New sump oil taken. After all works finished generator stated stopped many times for inspection after that slowly gradually increased load. It was run on full load for ½ hr. Just before stopping for inspection generator made big sound & power went off creating a black out. Standby generator started and taken on load. The damaged generator. was inspected, found No.6 unit connecting rod came out and bottom end bearing bolt broken.

1)#6 piston cooling nozzles were found choked.
2)No. oil was flowing to piston cooling
3)No bearing lubrication.