What was found
SERRATED BUSHING IN THROTTLE CONTROL LEVER WORE THROUGH LEVER AND SEPARATED THROTTLE CABLE FROM ENGINE. THE ENGINE IMMEDIATELY WENT TO IDLE AND PILOT LANDED AIRPLANE IN TUNDRA TOTALING THE AIRCRAFT. THE BOLT WITH PROPER HARDWARE AND TORQUE WAS STILL CLAMPING ROD END TO SERRATED BUSHING. WOULD HELP IF BUSHING THINNER THAN LEVER, BUT MAIN PROBLEM IS ENGINE GOES TO IDLE INSTEAD OF FULL THROTTLE WHEN DISCONNECTED FROM AIRFRAME THROTTLE CABLE. SUGGEST MODIFICATION TO FUEL SYSTEM TO CREATE FAIL SAFE DESIGN.