What was found
(CAN) IMH 13082.3 TTSN AIRCRAFT SNAGGED POWER LOSS DURING FINAL APPROACH. AIRCRAFT INSPECTED FOR WATER CONTAMINATION IN ALL FUEL SYSTEM DRAIN LOCATIONS. SMALL AMOUNT (NORMAL) FOUND AND FLUSHED OUT. ENGINE INSPECTED FOR DEFECTS, NO FOUND. ALL SPARK PLUGS REPLACED WITH SERVICEABLE PLUGS. ENGINE GROUND RUN SERVICEABLE. MAG DROP AND STATIC RPM WITHIN SERVICEABLE LIMITS. AIRCRAFT SENT OUT SUBJECT TO SATISFACTORY TEST FLIGHT. SUSPECTED CARB ICING IN FLIGHT. TEST FLIGHT: UNSATISFACTORY. RPM WANDERS FROM TEST FLIGHT CARBURETOR REMOVED WITH 648.3 TSO FROM IMH. REPLACED WITH SERVICEABLE CARB TSO 544.3 TSO. RIGGED, SAFTIED AND DUALED. AIRCRAFT GROUND RUN SERVICEABLE. SENT OUT SUBJECT TO SATISFACTORY TEST FLIGHT. TEST FLIGHT SATISFACTORY.