What was found
WHILE IN CRUISE FLIGHT, AN ATTEMPT TO LEAN THE MIXTURE WAS MADE. AFTER ABOUT THREE TURNS OF THE VERNIER CONTROL KNOB, A PUSH WAS FELT AND CONTROL WENT TO IDLE CUT-OFF. ATTEMPTS TO PUSH THE CONTROL IN FAILED. AN AIRPORT LANDING WAS MADE WITH PARTIAL POWER OBTAINED. AFTER LANDING, THE CONTROL WAS CYCLED, A CLICKING WAS HEARD, AND NORMAL OPERATION HAD RETURNED. THE CONTROL WAS REPLACED WITH A NEW PART. THE FAILED CONTROL WAS SENT TO CESSNA FOR EVALUATION. THE CONTROL HAD FAILED INTERNALLY. ANY BINDING OF AN ENGINE CONTROL SHOULD BE INVESTIGATED AND CORRECTED PRIOR TO FURTHER FLIGHT. **S/D** CESSNA'S EVALUATION DETERMINED THAT THE CONTROL WAS NOT P/N S1818-1, NOR WAS THE VENDOR A CESSNA APROVED SUPPLIER.