As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED THROTTLE VERY HARD TO MOVE. UPON INSPECTION, THE THROTTLE ARM WAS FOUND TO BE SEIZED AFTER THE THROTTLE CONTROL WAS REMOVED. THROTTLE ASSY WAS REMOVED FROM THE ENGINE AND THE THROTTLE AREM COULD NOT BE MOVED. NO VISIBLE SIGNS OF ANY OTHER DAMAGE TO UNIT. THE ADDITION OF LUBRICATION TO THROTTLE SHAFT MADE NO DIFFERENCE.