Supersedes Service Instruction No. 1275B September 23, 2008 MODELS AFFECTED Precision Airmotive RS and RSA Fuel Injectors installed on Lycoming aircraft engines. TIME OF COMPLIANCE At overhaul and as engine conditions require. Fuel nozzles can become clogged with a type of varnish from old fuel or from precipitate particles that are almost invisible to the naked eye. This condition may be...

Supersedes Service Instruction No. 1519 September 19, 2008 MODELS AFFECTED All Lycoming new, overhauled, rebuilt, or repaired (L)IO, AIO, HIO, IGO, IVO, (L)TIO, AEIO series engine with either a Precision Airmotive RSA­5 or RSA­10 series fuel injection servo. All Lycoming new, overhauled, rebuilt, or repaired (L)IO, AIO, HIO, IGO, IVO, (L)TIO, AEIO series engine with a Precision Airmotive...

DATE: August 22, 2008 MODELS AFFECTED Any Lycoming new, overhauled, rebuilt, or repaired (L)IO, AIO, HIO, IGO, IVO, (L)TIO, AEIO series engine with either a Precision Airmotive RSA­5 or RSA­10 series fuel injection servo which does NOT have a “G” marked on the regulator hex plug. All Lycoming new, overhauled, rebuilt, or repaired (L)IO, AIO, HIO, IGO, IVO, (L)TIO, AEIO series engine with a...

Supersedes Service Instruction No. 1257F May 16, 2008 MODELS AFFECTED Lycoming supercharged and turbocharged aircraft engines. TIME OF COMPLIANCE During engine maintenance. It is important to note that all Lycoming supercharged (GSO and IGSO) engines attain take­off power at less than full throttle, while some turbocharged engines attain take­off power only at full throttle and others at part...

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...