What was found
WHILE DOING A GROUND RUN-UP PRIOR TO A 100-HOUR INSPECTION, MAINTENANCE NOTICED THE ENGINE, UPON REACHING OPERATING TEMP, BEGAN TO RUN ROUGH AT LOWER POWER SETTINGS. THE FUEL FLOWS ALSO WERE EXTREMELY ERRATIC. NO FURTHER ACTION HAS BEEN TAKEN. THIS IS AN ORIGINAL FUEL SERVO THAT WAS SHIPPED/INSTALLED AT THE FACTORY. REMOVED FLOW DIVIDER COVER AND FOUND SMALL METAL FLAKES ON UNDERSIDE. ALSO, FOUND SCORING ON PISTON. FLUSHED OUT FLOW DIVIDER AND REMOVED SCORING WITH SCOTCH BRITE. ACFT HAS FLOWN 10 HOURS WITH NO FURTHER PROBLEMS.