Service Instruction No. 1506 A

June 28, 2016

MODELS AFFECTED

Lycoming O, IO, AEIO-360 or O, IO, AEIO-320 series engines presently equipped with impulse coupling magnetos.

TIME OF COMPLIANCE

At owner’s discretion

REASON FOR REVISION

Added engine models to “MODELS AFFECTED”; clarified details in the text of this Service Instruction.

This Service Instruction contains instructions to replace impulse coupling magnetos on affected fourcylinder Lycoming engine models with a left retard breaker magneto, a right plain magneto, and an ignition vibrator. This replacement changes the configuration from an impulse coupling to a shower of sparks type configuration.