What was found
PILOT REPORTED LOSS OF RPM DURING TAKEOFF, DURING TROUBLESHOOTING IT WAS DISCOVERED RPM WOULD RETURN WHEN THE MIXTURE CONTROL WAS LEANED, INDICATING A RICH MIXTURE CONDITION. DURING A VISUAL INSPECTION OF THE INDUCTION SYSTEM (I.E. AIRBOX AND CARBURETOR) A PIECE OF BAFFLE SEAL MATERIAL WAS DISCOVERED PARTIALLY OBSTRUCTING THE BOOST VENTURI IN CARBURETOR. FARTHER EXAMINATION REVEALED THE SOURCE OF THE BAFFLE MATERIAL WAS FROM THE CARB HEAT BUTTERFLY VALVE, THE VALVE DESIGN SANDWICHES THE MATERIAL IN BETWEEN TWO LAYERS OF ALUMINIUM TO CREATE THE SEAL IN THE AIRBOX OVER TIME THE MATERIAL WEAKENED AND EVENTUALLY TORE OFF AND WAS "SUCKED" INTO THE BOOST VENTURI CAUSING THE OBSTRUCTION AND RPM LOSS