What was found
AFTER INSTALLING NEW CYLINDER ASSY SA47006S-A20P WITH NEW PISTON ASSY PN SA640518, WE WERE PERFORMING BREAK IN RUN AT LOW POWER, FIRST AT 800 RPM FOR 2 MIN. SHUTDOWN ENGINE, CLEANED FOULED PLUGS DUE TO OIL IN CYLINDER FROM ASSY. RAN ENGINE AT 1000 RPM FOR 3 MIN. SHUTDOWN AND CLEANED SPARK PLUGS AGAIN. RESTARTED ENGINE AND ADVANCED TO 1200 RPM, THE CYLINDER CLEARED OUT AND THEN STOPPED AFTER A FEW SECONDS. AFTER REMOVING THE OIL PAN AND NR 1 CYLINDER THE PISTON APPEARED TO HAVE FRACTURED ALONG A CASTING FAULT IN THE PISTON PIN BOSS. THE RESULTING DEBRIS BENT THE CAM SHAFT, BROKE BOTH CRANKSHAFT HALVES. (K)