# SDR 2026FA0000052

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 23, 2025
- Submitted: January 22, 2026
- Operation: General aviation
- Aircraft: [N77541](https://openairdocs.org/aircraft/N77541), registered now
- Make and model: Piper J3C-65
- Registry model: [Piper J3C-65](https://openairdocs.org/model/piper-j3c-65) (OpenAirDocs)
- Aircraft serial: 22031
- Aircraft time: 3,842 hours
- Engine: Cont IO550N
- Engine time: 2,492 hours
- Propeller: Mtprop MTV14D
- System (JASC): [7321 · Fuel Control/Turbine Engines](https://openairdocs.org/jasc/7321)
- Part: Spark Plug
- Part number: RHB32S
- Condition: Cracked
- Location: Cylinder #3
- Stage of operation: CR
- How discovered: O
- Nature of condition: R, J, E
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2026FA0000052

## Discrepancy

LEVELED AT 4000FT, ENGINE POWER WAS REDUCED TO 80% WITH FUEL CONSUMPTION LEANED TO 17GAL/HR. AFTER BEING SET IN THIS CRUISE PROFILE FOR APPROXIMATELY 2 MINUTES, THE ENGINE BEGAN TO RUN ROUGH. THE PILOT THEN RICHENED THE MIXTURE WHICH DID NOT FIX THE ISSUE, HE PREFORMED MULTIPLE TROUBLE SHOOTING THROTTLE AND MIXTURE ADJUSTMENTS, BUT NONE OF THESE REMEDIED THE ISSUE EITHER PROMPTING THE RETURN TO KDPA. DURING INSPECTION I REMOVED SPARK PLUGS FROM CYLINDER #3 DUE TO CHT READING LOW ON DIAGNOSTIC RUN. VISUALLY INSPECTED AND TESTED TOP AND BOTTOM SPARK PLUGS; FOUND CERAMIC INSULATORS TO BE CRACKED ON BOTH SPARK PLUGS.

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