Supersedes Service Bulletin No. 505A December 1, 1997 MODELS AFFECTED The following Textron Lycoming four cylinder engines which utilize fixed pitch propellers except those installed in rotary wing aircraft or new engines shipped after February 15,1997: All 320 series engines; and All 180 horsepower, 360 series engines except the O-360-A4A, -A4D, A4G, - A4J, -A4K, -A4M, -A4N, -A4P -C4F, -C4P, IO...

DATE: January 18, 1996

(Supersedes Service Bulletin No. 381, Service Bulletin No. 385, Service Bulletin No. 454B, Service Bulletin No. 455D, and Service Bulletin No. 456F) DATE: September 1, 1995 MODELS AFFECTED See attached Lists I and II for specific models and serial numbers. All new, overhauled and remanufactured engines shipped from the factory after March 31, 1985 are in compliance with this Service Bulletin. TIME...

DATE: June 3, 1988 MODELS AFFECTED All AEIO-540-D series, IO-540 (250 & 260 horsepower) engines converted for aerobatic flight or any other 540 engines employing a 2-3/8 diameter main bearing seal used in unlimited category aerobatic maneuvers. TIME OF COMPLIANCE Visual inspections within next 10 hours and at each 10 hour interval of unlimited aerobatics or earlier at owner's discretion. Reports...

Supersedes Service Letter No. L255 May 13, 2016 To All Owners and Operators of Lycoming Piston Aircraft Engines An alternate diaphragm-type fuel pump P/N 62B26931 is approved as an equivalent replacement for the current fuel pump P/N LW-15473 except as noted in Table 1.

Supersedes Service Letter No. L264 To All Owners and Operators of Lycoming Engine Models with Champion Magnetos REASON FOR REVISION Deleted Table 1 and Figure 1 in the attached Service Letter If any of the following occur on a Lycoming engine after installation of Champion Slick 4300/6300 Series magnetos, complete the instructions per the attached Champion Slick Magneto Service Letter 4300/6300-74...

Supersedes Service Letter No. L261 To All Owners and Operators of Helicopteres Guimbal Cabri G2 with the following carburetors: Lycoming part number (P/N) 61B26215 (AVStar P/N AV10-6110) Lycoming P/N 61B26215-L (AVStar P/N AV10-6110) Lycoming P/N 61B28159 (AVStar P/N AV10-6500) REASON FOR REVISION Added alternate carburetor part number In support of a request from Helicopteres Guimbal, there is an...

March 11, 2015 To All Owners and Operators of Lycoming IO-540-AC1A5 and TIO-540-AJ1A Engine Models This Service Letter is in response to reports of discolored paint on engine cylinders of IO-540-AC1A5 and TIO-540-AJ1A engine models. Discoloration on an engine cylinder can be the result of the unique engine configuration and the ecologically friendly paint applied to the cylinder at the factory and...

December 31, 2014 Models Affected All Owners and Operators of Lycoming Aircraft Engines Table 1 of this Service Letter identifies new piston ring part numbers (P/N) that replace existing piston ring part numbers. All of the new piston rings are equivalent to the existing piston rings. Existing and new piston rings can be mixed in the same engine, but be sure to use either all new piston rings in a...