DATE: October 2, 2012 MODELS AFFECTED 320/360 series Lycoming engines with crankcase casting part number C11B20061­R Revision M or later and C11B20061­L Revision M or later. TIME OF COMPLIANCE As required. Lycoming four­cylinder 320 and 360 series engine models can have a tight fit at the nose area (Figure 1) in some airframes. There is not enough clearance between the engine and adjacent airframe...

DATE: June 27, 2012 MODELS AFFECTED Engines that have Fuel Pump Plunger P/N 61544 installed. TIME OF COMPLIANCE At next engine overhaul, whenever fuel pump plunger appears damaged, or earlier at owner’s discretion. This Service Instruction is notification that Fuel Pump Plunger P/N 23D26777 is an approved replacement for Fuel Pump Plunger P/N 61544.

Supersedes Service Instruction No. 1256E April 5, 2012 MODELS AFFECTED Intake and exhaust valve guides on all Lycoming engines except as listed below: Intake valve guides only on O-235 and O-290 series unless modified in accordance with the latest revision of Service Instruction No. 1246. TIME OF COMPLIANCE When replacing valve guides This Service Instruction identifies flanged intake and exhaust...

DATE: October 4, 2012 TIME OF COMPLIANCE At each removal and installation of the starter electrical lead. MODELS AFFECTED All Lycoming direct drive engines. This Service Instruction includes specific installation and removal requirements of the electrical leads for Hartzell Engine Technologies (HET), LLC starters.

Supersedes Service Instruction No. 1143B, Supplement No. 2, 3 and 4 to Service Instruction No. 1143B and Service Letter No. L217 November 10, 2011 MODELS AFFECTED All Lycoming piston aircraft engines with dynamic counterweights TIME OF COMPLIANCE During engine overhaul. This Service Instruction includes all of the necessary information to examine, remove, prepare, and install counterweight...

DATE: October 31, 2011 MODELS AFFECTED All Lycoming engines with counterweights installed. TIME OF COMPLIANCE As required. This Service Instruction contains procedures and dimensions to remove, inspect, and install counterweights and rollers for Lycoming engine crankshafts.

Supersedes Service Instruction No. 1497 April 12, 2011 MODELS AFFECTED Lycoming IO-360-L2A engines installed in Cessna C172R and 172S aircraft used in training operations TIME OF COMPLIANCE As required during aircraft operations The flight training environment makes an engine more susceptible to spark plug fouling, decreased efficiency, and excessive fuel consumption. Some of the flight training...

Supersedes Service Instruction No. 1484B March 29, 2011 MODELS AFFECTED All Lycoming reciprocating aircraft engines TIME OF COMPLIANCE When installing a fuel metering device, carburetor, fuel injector servo or “AN” fuel pump This Service Instruction includes the steps and torque values for installation of a fuel metering device, carburetor, fuel injector servo or “AN” fuel pump.

Supersedes Service Instruction No. 1442 March 28, 2011 MODELS AFFECTED All Lycoming piston engines with dual magneto accessory housing TIME OF COMPLIANCE At next overhaul or evidence of a filter element collapse This Service Instruction identifies a new spring, P/N 05S21021 that replaces spring P/N 55C21021 in the oil filter bypass valve. This replacement is to be done during overhaul or if oil...