Time Between Overhaul (Tbo) - Lycoming IO-390-D Series Maintenance Manual

Tool No.
ST-23 Gage, Valve Clearance 0.028 to 0.080 in.
ST-25 Compressor, Valve Spring
ST-92 Counterweight Bushing Driver
ST-93 Counterweight Fixture Assembly
ST-93-3 Depth Control Spacer
ST-93-5 Depth Control Spacer
ST-115 Tool, Install and Remove Propeller Flange Bushings
ST-131 Belt Tension Dial Gage
ST-142 Shroud Tube Wrench
ST-222 Plate, Torque Hold-Down
ST-271 Puller, Crankcase Thru-Stud
*ST-310 Gage, Check Bell-Mouthing of Exhaust Valve Guides
ST-317 Driver, Crankcase Thru-Stud
ST-383 Tool, Crankshaft Oil Seal Installation
ST-389 Tool, Crankcase Separating
ST-483 Test Plate
ST-485 Compressor, Piston Ring
64530 Connecting Rod Parallelism and Squareness Gage
64526-2 Block, Cylinder
64535 Connecting Rod Bushing Removal Drift
64536 Replacement Drift
64593 Expanding and Staking Tool, 0.71 in. (18 mm) Spark Plug Heli-Coil
64597 Connecting Rod Bushing Replacement Block
64594 Inserting Tool, 18 MM Spark Plug Heli-Coil
64596-1 Tap, 18 mm Heli-Coil
64767 Finish ID Gage
64892 Circlip Check Gage
64941 Tappet Assembly Tool
* Gage, Check Bell-Mouthing of Exhaust Valve Guides (ST-310) includes Gage Adapter ST-310-9

Time Between Overhaul (TBO)

4.
Refer to the latest revision of Service Instruction No. SI-1009 for any changes or special
circumstances for the recommended TBO.
Lycoming Engines recommends engines be sent to the factory for overhaul.
05-00
Page 2
Table 1 (Cont.)
Tools for Service and Maintenance
Nomenclature and Description
®
Spark Plug Bottom Tap 0.010 in. (0.254 mm) OS
IO-390-D Series Engine Maintenance Manual
IO-390-D Series Engine Maintenance Manual
®
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March 2020