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Lycoming Home > Support > Publications > Service Letters

Service Letters

From time to time, Lycoming issues Service Letters. Service Letters usually pertain to service policies or announce available products or improvements for Lycoming engines.

Service Letters are available from Lycoming Distributors. Complete sets of Service Bulletins, Instructions and Letters are available for purchase in both hard copy and electronic form either directly from Lycoming or through a Lycoming Distributor.

Service Letter No. SL255
Approved diaphragm-type fuel pumps

Service Letter No. SL254
Lycoming model designation for all carburetors

Service Letter No. SL253
Warranty Repair of AvStar Fuel Systems, Inc. Fuel Control Products

Service Letter No. SL251
Connecting Rod Bolt Marking

Service Letter No. SL250A
Lycoming Engines Exchange Engine Core Policy

Service Letter No. SL249
Interim Alternative to Address the Discontinuation of Teledyne Dual Magnetos

Service Letter No. SL248
Upgraded O-235 crankcase

Service Letter No. SL247A
Shelf Life Requirements

Service Letter No. SL247A Supplement 1
Shelf Life Requirements

Service Letter No. SL245
Special Service Publication No. SSP-567, Camshaft Regrinding

Service Letter No. SL244
Revision to Appendix 1 in Service Bulletin No. 569

Service Letter No. SL242
Improved Lower Idle Valve in Fuel Injectors

Service Letter No. SL240A
Lycoming, Part Numbers Identified by -70 or -85 Suffix

Service Letter No. SL234B
Tool Rental Program

Service Letter No. SL230B
Microfiche, Publications Available on

Service Letter No. SL221C
Fuel Control Products, Precision, Warranty Repair of

Service Letter No. SL220C
Wide Deck Cylinder Configuration on Lycoming Engines

Service Letter No. SL199
Fuel, Recommendations Regarding Use of

Service Letter No. SL185B
Fuel, Higher Octane Aviation, Use of 100LL for Engines Rated 80/87 Octane

Service Letter No. SL180B
Engine Preservation for Active and Stored Aircraft

Service Letter No. SL173C
Magneto, Slick Electro Bulletin No. 2-80, "Recommended Maintenance and Inspection"

Service Letter No. SL-114AV
Reciprocating Engine and Accessory Maintenance Publications

Service Letter No. SL-114AU Supplement 2
Reciprocating Engine and Accessory Maintenance Publications

Service Letter No. SL-114AU Supplement 1
Reciprocating Engine and Accessory Maintenance Publications

Service Letter No. SL-114AU
Reciprocating Engine and Accessory Maintenance Publications