As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
8372.5 HRS MAGNETO INSTALLED. 8509.9 HRS ENGINE BECAME HARD TO START. RESET MAGNETO TO ENGINE TIMING AND REPLACED SPARK PLUGS. 8540.2 HRS ENGINE STILL HARD TO START. REMOVED MAGNETO AND SENT FOR EVALUATION. INTERNAL TIMING FOUND TO BE INCORRECT.