# SDR 2004FA0000914

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 22, 2004
- Submitted: November 8, 2004
- Operation: General aviation
- Aircraft: N4068L
- Make and model: Cessna 421
- Registry model: [Cessna 421](https://openairdocs.org/model/cessna-421) (OpenAirDocs)
- Aircraft serial: 4210068
- Engine: Cont GTSIO520D
- System (JASC): [8530 · Reciprocating Engine Cylinder Section](https://openairdocs.org/jasc/8530)
- Part: Rocker
- Part number: 6399576
- Condition: Broken
- Location: Nr 3 Cylinder
- Component: Cylinder, Cont
- Stage of operation: IN
- How discovered: C
- Nature of condition: R
- Precautionary procedure: E
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2004FA0000914

## Discrepancy

ANNUAL PRE-INSPECTION RUN-UP RAN GOOD.  POST INSPECTION RUN-UP RAN ROUGH.  SUSPECTED A STICKING VALVE.  FURTHER INVESTIGATION REVEALED A BROKEN EXHAUST ROCKER ARM AND STUCK VALVE FOR NR 3 CYLINDER ON THE LEFT ENGINE.  ALSO, NOTED IS AN APPARENT INCLUSION IN THE BROKEN ROCKER ARM.

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