FAILURE OF THE PILOT TO PERFORM EMERGENCY PROCEDURES FOR LOSS OF ENGINE POWER (INCLUDING HIS FAILURE TO FEATHER THE PROPELLER OF THE AFFECTED ENGINE). FACTORS RELATED TO THE ACCIDENT WERE: INADEQUATE MAINTENANCE, CONTAMINATION IN THE FUEL SYSTEM, AND OVERHEAT FAILURE OF THE #1 AND #4 PISTONS IN THE RIGHT ENGINE (FROM PREIGNITION OR DETONATION).