DATE: March 14, 2008 MODELS AFFECTED All Lycoming aircraft engines employing any model of Precision Airmotive RSA flow dividers. TIME OF COMPLIANCE Whenever the engine has starting difficulties in cold weather. This reprint is current at the time Lycoming Service Instruction No. 1518 is issued. However, when complying with this Service Instruction, insure that compliance is in accordance with the...

Supersedes Service Instruction No. 1148C October 12, 2007 MODELS AFFECTED All Lycoming engines using float type carburetors. TIME OF COMPLIANCE During engine operation. Under certain moist atmospheric conditions (generally at a relative humidity of 50% or greater) and at temperatures of 20° to 90°F it is possible for ice to form in the induction system.

DATE: October 27, 2006 MODELS AFFECTED Lycoming model TIO-540-AK1A aircraft engines. TIME OF COMPLIANCE At overhaul or at owner’s discretion. A slight increase in engine performance has been found by changing the engine timing from 20° BTC to 23° BTC. This modification has been incorporated in the current production of both new and rebuilt engines. This timing change does not affect the normal...

Supersedes Service Instruction No. 1340 May 25, 2006 MODELS AFFECTED All Lycoming aircraft engines except the following: O-235, O-290, O-435-A, GO-435-C2, VO-435, TVO-435. TIME OF COMPLIANCE At anytime heavy wall piston pins are selected for use. Heavy wall piston pin P/N LW-14078 supersedes heavy wall piston pin P/N LW-14077 and thin wall piston pins P/N 69650, P/N LW-13444, P/N LW-12383 and P/N...

Supersedes Service Instruction No. 1105A May 5, 2006 MODELS AFFECTED All Lycoming four cylinder direct drive aircraft engines except those with the Lycoming P/N 73383 lock plate. TIME OF COMPLIANCE During 100-hour inspection periods. On certain older four cylinder model engines, either the generator or alternator is mounted to the crankcase using the crankcase perimeter bolts. On later versions of...

Supersedes Service Instruction No. 1438 December 9, 2005 MODELS AFFECTED All four and six cylinder, dual magneto engines with rear mounted propeller governor drives. TIME OF COMPLIANCE Anytime the propeller governor is installed. The use of a P/N LW-12347 propeller governor pad plate and two P/N 72053 gaskets on dual magneto engines with rear mounted propeller governor drives is necessary with...

Supersedes Service Instruction No. 1511 May 26, 2005 MODELS AFFECTED The following Textron Lycoming four cylinder engines which utilize fixed pitch propellers except those installed in rotary wing aircraft. 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, and AEIO-360-B4A engine models. TIME OF COMPLIANCE...

Supersedes Service Instruction No. 1164A April 12, 2005 MODELS AFFECTED All Lycoming direct drive engines except engines that incorporate an integral crankcase and accessory housing assembly. TIME OF COMPLIANCE When oil pump replacement is necessary. Replacement parts for the original two-piece oil pump body and cover assembly are no longer available. One-piece oil pump bodies which have been...

DATE: September 23, 2004 MODELS AFFECTED All Lycoming model engines. TIME OF COMPLIANCE Whenever new bearings are installed. Lycoming has recently upgraded the main and connecting rod bearings. The superseded bearing part numbers and the upgraded bearing part numbers are shown in the table below. Lycoming requires the use of the upgraded bearing whenever new bearings are installed.