SERVICE LETTER NO. L288 Alternate Bolt Locking of Wastegate Solenoid Valve DATE: December 16, 2021 TO: Owners and Operators of Lycoming TEO-540-C1A REASON FOR PUBLICATION: This Service Letter announces that the repetitive need to remove and install safety wire on the solenoid valve attaching bolt can be eliminated by usage of lock washer P/N STD-160 in combination with Loctite® 243 or equivalent.

SERVICE INSTRUCTION NO. 1586 DATE: December 2, 2021 SUBJECT: Oil Cooler Bypass Valve Assembly Replacement MODELS AFFECTED: Lycoming TEO-540-C1A TIME OF COMPLIANCE: At next scheduled oil change

SERVICE INSTRUCTION NO. 1587 DATE: February 3, 2022 SUBJECT: Reprint of AVStar Service Information Letter No. AFS-SIL-03 MODELS AFFECTED: All Lycoming engine models with an AVStar LVC-3-3A, LVC-3-3PA, LVC-5-4PA, LVC-5-5BPA, LVC-5-5PA, LHC-6-6BPA & LHC-6-6BA TIME OF COMPLIANCE: Whenever adjustments are made to an AVStar carburetor installed on a Lycoming engine

SERVICE LETTER NO. L289 Valve Spring Part Numbers DATE POSTED: March 2, 2022 TO: All Owners, Operators, and Maintenance Providers of Lycoming Aircraft Engines REASON FOR PUBLICATION: Lycoming has released new valve springs with new part numbers that are interchangeable with the old valve springs.

Supersedes Service Instruction No. 1533 D April 7, 2022 MODELS AFFECTED All Lycoming reciprocating aircraft engines using rotary-style fuel pumps TIME OF COMPLIANCE As Required for Replacement REASON FOR REVISION Added 62E28152 fuel pump to Table 1

Service Bulletin No. 646A T-Bolt Clamp Inspection April 22, 2022 MODELS AFFECTED Lycoming Engines models TEO-540-C1A; TIO-540-R2AD, -W2A; (L)TIO-540-F2BD, -J2B, -J2BD TIME OF COMPLIANCE Inspection of non-conforming T-bolt clamp every 50 hours or replacement with conforming T-bolt clamp at owner’s discretion. Replacement with conforming T-bolt clamp must not exceed 12 months.

SERVICE INSTRUCTION NO. 1583 DATE: May 18, 2022 SUBJECT: Front Expansion Plug Replacement MODELS AFFECTED: All Lycoming opposed series engines using a front expansion plug TIME OF COMPLIANCE: As necessary when front expansion plug replacement is required