As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN SELECTING DIFFERENT FUEL TANK, PANEL MOUNTED FUEL SELECTOR VALVE HANDLE-PIN WHICH HOLDS HANDLE TO SHAFT CAME OUT OF POSITION. THIS WOULD NOT ALLOW TANK SELECTION TO BE MADE. SUBMITTER SUGGESTED TO PREVENT RECURRENCE DURING PRE-FLIGHT AND ROUTINE INSPECTION, MOVE HANDLE, AND CHECK PIN FOR LOOSNESS AND PROPER OPERATION.