As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF OFF THE #1 (LT. ) ENGINE MADE A LOUD POPPING NOISE AND WAS ROUGH. AFTER CONSULTATION WITH MANUFACTURER, THE CYLINDER HEAD ASSEMBLY WAS CHANGED. THE CONDITION DID NOT OCCUR ON POST MAINTENANCE FLIGHT ANDSUBSEQUENT FLIGHTS.