Service Instruction No. 1191 A

Cylinder Compression

Publications

Supersedes Service Instruction No. 1191

September 28, 1998

MODELS AFFECTED

All Lycoming aircraft engines.

TIME OF COMPLIANCE

As required to determine cylinder compression

The condition of the working parts in the combustion chamber of a cylinder can be determined by measuring the static leak rate of the cylinder as compared to the leak rate through an orifice of specified size. This is accomplished by attaching a differential compression measuring device, which incorporates the orifice, to one spark plug hole of the cylinder while the piston is at top center of the compression stroke.

Get It Exchanged

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