What was found
ALL FOUR NUTS, FLAT AND LOCK WASHERS, WERE DISCOVERED MISSING FROM THE FOUR STUDS ON THE INTAKE MANIFOLD THAT THE CARBURETOR IS MOUNTED ON. PROBLEM DISCOVERED WHEN ENGINE FAILED ON LANDING AND WOULD NOT RESTART. CURRENT COMBINATION OF NUT, LOCK WASHER AND FLAT WASHER IS NOT SUFFICIENT TO WITHSTAND ENGINE VIBRATION. SUBMITTER RECOMMENDS PERIODIC TORQUE CHECKS OR DIFFERENT LOCKING DEVICE.