As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, THE PILOT ATTEMPTED TO REDUCE POWER. THE THROTTLE JAMMED AND WOULD NOT MOVE TO BELOW 2,300 RPM. THE MIXTURE WAS PLACED IN ICO FOR LANDING. THE DISCHARGE TUBE HAD COME LOOSE AND WEDGED IN THE THROTTLE PLATE. SUBMITTER STATED THEY HAVE A FLEET OF 16 OF THESE AIRCRAFT. THROTTLE TUBE IS INSPECTED EVERY 100 HOURS.