What was found
DURING RUNUP, PROP FEATHER CHECK CONDUCTED NORMALLY. WHEN ADVANCING POWER LEVER TO DO A PROP OVERSPEED TEST, COULD NOT REACH 1900 RPM WITH POWER LEVER FORWARD. HIGHEST RPM ACHIEVED WAS 1700. SHUTDOWN AND RESTART. DURING THE START, AT LOW IDLE, FLAMES SHOT OUT OF THE EXHAUST. SHUTDOWN AND MOTORED STARTER FOR A MINUTE. ON A SUBSEQUENT START UP, FLAMES SHOT OUT AGAIN. A NEW FCU WAS INSTALLED. ENGINE PERFORMED NORMALLY. ENG MFG IS EXAMINING THE FAILED FCU IN THEIR LAB.