Lycoming YO-233-B2A Maintenance Manual page 16

Engine Serial Number
Every engine sent from the factory is identified by a
unique serial number. The engine serial number is
identified on the engine data plate (Figure 2). Do not
remove the engine data plate.
If a data plate is ever lost or damaged, refer to the latest
revision of Service Instruction No. SI-1304 for data
plate replacement information.
Cylinder Number Designations
• The propeller is at the front of the engine and the accessories are at the rear of the engine.
• In a top view of the engine, the left side cylinders are 2-4. Cylinder 2 is at the front of the
engine. Refer to Figure 3.
• In a top view of the engine, the left side cylinders are 1-3. Cylinder 1 is at the front of the
engine. Refer to Figure 3.
• The firing order of the cylinders is 1-3-2-4.
Introduction
Page xiv
Top View of Engine – Cylinder Number Designations
YO-233-B2A Engine Maintenance Manual
TEO-540-A1A Engine Maintenance Manual
Figure 3
© 2021 Avco Corporation. All Rights Reserved
Figure 2
Engine Data Plate
February 2021