As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT CLIMB OUT AFTER TAKEOFF THE ENGINE EXPERIENCED A 200 RPM DECREASE DUE TO THE FUEL SERVO INCREASING THE FUEL FLOW FROM 13.0 GPH TO 16.5 GPH DUE TO AN UNDETERMINED REASON. PILOT APPLIED ALTERNATE AIR WHICH IMPROVED THE SITUATION SLIGHTLY AND AIRCRAFT RETURNED TO AIRPORT FOR UNEVENTFUL LANDING. UNABLE TO DUPLICATE THE PROBLEM ON GROUND RUN UP. FUEL SERVO WAS DETERMINED TO BE DEFECTIVE AND REPLACED WITH A REPAIRED UNIT AND ENGINE PERFORMED SATISFACTORY. DEFECTIVE FUEL SERVO WAS RETURNED TO AVSTAR FUEL SYSTEMS FOR WARRANTY REPAIR.