As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PROP INSTALLED ON ACFT HAD PROP ZERO PITCH LATCH KIT INSTALLED IAW STC SP96-1. THE PROP HAD A HARD TIME COMING OFF LATCHES. PROP WAS DISMANTLED TO THE EXTENT NECESSARY TO DETERMINE THAT THE WRONG FLYWEIGHT SPRINGS HAD BEEN INSTALLED AT THE PREVIOUS O/H. SPRINGS SHOULD BE MODIFIED IAW THE STC. PROPER SPRINGS PN B-5020WPL INSTALLED AND PROP RETURNED TO SERVICE.