# SDR 2025FA0000296

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 23, 2025
- Submitted: April 23, 2025
- Operation: General aviation
- Aircraft: [N772FG](https://openairdocs.org/aircraft/N772FG), registered now
- Make and model: Cessna 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (OpenAirDocs)
- Aircraft serial: 172S13277
- Aircraft time: 264 hours
- Engine: Lyc IO360L2A
- Engine time: 264 hours
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Exhaust Valve
- Part number: 17B23936
- Condition: Stuck
- Location: Nr 4 Cylinder
- Part time: 264 hours
- Component: Cylinder, Lyc
- Component part number: 05K21104
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2025FA0000296

## Discrepancy

EXTREME VIBRATION OF AIRCRAFT ENGINE AFTER START UP.  TROUBLESHOT AND FOUND #4 CYLINDER EXHAUST VALVE STUCK OPEN

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