What was found
AFTER ENGINE START, THE ENGINE BEGAN RUNNING VERY ROUGHLY. THE ENGINE RPM BEGAN TO DECREASE STEADILY UNTIL THE ENGINE DIED COMPLETELY. THE PILOTS EXITED THE ACFT AND NOTED FUEL WAS STREAMING FROM OUT OF THE ENGINE COWLING. PILOTS IN ANOTHER AIRCRAFT REPORTED SEEING COPIOUS AMOUNTS OF BLACK SMOKE BILLOWING FROM THE AIRCRAFT'S EXHAUST WHILE IT WAS STILL RUNNING. A MAINTENANCE TECH INSPECTED THE ACFT AND NOTED THE CARBURETOR WAS LEAKING LARGE AMOUNTS OF FUEL FROM THE NOZZLE, AS THOUGH THE FLOAT HAD SUNK.