Service Instruction No. 1290F
Repair of Oil Leakage at Crankcase Thru-Stud Locations; Assembled and Unassembled Engines.
Publications
Service Instruction No. 1290F
DATE:
July 24, 2009
WEBSITE PUBLISH DATE:
June 17, 2025 due to frequent requests.
MODELS AFFECTED:
All Lycoming wide cylinder flange engines identified by the suffix “A” or “E”
after the engine serial number and incorporating body-fit thru-studs such as:
O, IO, AIO, AEIO and LIO-320 series engines
O, IO, AIO, AEIO, HIO, LIO, TO and TIO-360 series engines
O, IO, AEIO, TIO and LTIO-540 series engines
TIO-541 and TIGO-541 series engines
IO-720 series engines
TIME OF COMPLIANCE:
As required.
