# SDR 2026FA0000684

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 5, 2026
- Submitted: September 5, 2026
- Operation: General aviation
- Aircraft: [N225WS](https://openairdocs.org/aircraft/N225WS), registered now
- Make and model: Cessna 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (OpenAirDocs)
- Aircraft serial: 172S9800
- Aircraft time: 6,379 hours
- Engine: Lyc IO360L2A
- Engine time: 8,435 hours
- Propeller: Mcauly 1A170E
- System (JASC): [7414 · Magneto/Distributor](https://openairdocs.org/jasc/7414)
- Part: Seal
- Condition: Failed
- Location: Magneto
- Component: Magneto, Hartzl
- Component part number: 4371
- Stage of operation: IN
- How discovered: V
- Nature of condition: R
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2026FA0000684

## Discrepancy

AFTER COMPLETION OF THE ANNUAL INSPECTION, WE PERFORMED A POST INSPECTION RUN.  DURING IDLE WE CHECKED EACH MAGNETO AND FOUND THAT THE ENGINE RAN SIGNIFICANTLY ROUGHER ON THE LEFT MAGNETO THAN THE RIGHT MAGNETO.  AT HIGHER RPM OPERATION WAS NORMAL. REMOVED LEFT MAGNETO AND OPENED FOR INSPECTION.  IT WAS FOUND THAT THE MAGNETO OIL SEAL FAILED.  THIS MAGNETO IS NEW WITH ONLY 105 HOURS SINCE INSTALLATION.

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