Service Instruction No. 1129 E

Methods of Checking DC Alternator and Generator Belt Tension

Publications

Supersedes Service Instruction No. 1129D

September 23, 2025

MODELS AFFECTED

All Lycoming direct drive engine models

TIME OF COMPLIANCE

During periodic maintenance inspection of the engine and at anytime the alternator or generator belt is installed.

REASON FOR REVISION

Added 14 millimeter wide belt and torque values to table 1.

This Service Instruction provides Instructions for Continued Airworthiness (ICA).

 

DOWNLOAD PUBLICATION
header_0

Product Support Network

Lycoming has a worldwide product support network so you can access the technical, training, and service information you need at your own convenience.

We are here to help. As a Lycoming customer, you have access to our worldwide team of authorized distributors and service centers. The Lycoming team helps you stay up-to-date on industry insights, and provides information about how to care for your engine.

Learn more