As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT COMPLAINED OF STIFF THROTTLE. FOUND THE HA-6 CARBURETOR VERY STIFF. FOUND THE SEAL RETAINERS FOR THE THROTTLE SHAFT, ACCELERATOR ROD AND ECONOMIZER RODS TO BE SEATED TOO DEEPLY CAUSING THE SEALS TO 'GRAB' THE SHAFTS TIGHTLY MAKING THROTTLE ADJUSTMENTS DIFFICULT. MARVEL SHEBLER ADDRESSED THIS PROBLEM IN S/B A2-78 ISSUED JANUARY 1979. HAVE FOUND A TOTAL OF 5 FACTORY NEW CARBS WITH THIS SAME CONDITION