Service Instruction No. 1492 D

Piston Pin Plug Wear Inspection


Supersedes Service Instruction No. 1492C

March 20, 2009


All Lycoming new or factory rebuilt or factory overhauled engines shipped from Lycoming after January 1, 1994, and all engines which have had a Lycoming Cylinder Kit installed after January 1, 1994, except O-235 models.


At next oil change/oil filter replacement, not to exceed 50 hours of engine operation (first 25 hours and next 25 hours for new, rebuilt, or newly overhauled engines) and at each 50 hours of engine operation thereafter.

Field reports indicate an increase in incidents of abnormally worn piston pin plugs in some units shipped after January 1, 1994. Evidence of such wear can be detected by use of an oil filter content inspection or spectrographic oil analysis.

Get It Exchanged

Use our Engine Exchange Program to order a new, rebuilt, or overhauled engine to experience more airtime and less downtime.