IO-390-D Series Engine Maintenance Manual
© 2020 Avco Corporation. All Rights Reserved
05-20
March 2020
Page 21
IO-390-D Series Engine Maintenance Manual
50-Hour Engine Inspection Checklist for IO-390-D Series Engines (Cont.)
Inspection Item
Comments
Results/Notes
Done
Remove, examine, clean and
install the oil suction screen at the
oil sump. Replace the oil suction
screen if distorted, deformed or
open areas are found in the mesh.
If blockage is found, record
and identify the blockage
(metal, carbon, etc.)
Refer to the section in
Chapter 12-10: "Oil
Suction Screen
Removal/Inspection/
Cleaning/Installation."
Ignition System
EIS
Make sure all leads are securely
attached to the EIS
Refer to the “EIS
Installation” section in
Chapter 74-30.
Magneto (Optional)
Make sure that the P-leads are
securely attached to the magneto
condenser studs. Torque the P-
lead nut to 13 to 15 in. lb (1.5 to
1.7 Nm) as necessary.
Refer to the aircraft
manufacturer's
recommendations to make
sure the ignition switch and
P-lead are operating
correctly.
Remove spark plug connector
nuts and examine spark plug
cable leads and ceramics for
corrosion and deposits.
Replace spark plugs as necessary
per Chapter 74-20.
Corrosion and deposits are
evidence of leaking spark
plugs or of improper
cleaning of the spark plug
walls or connector ends.
Refer to the section “Spark
Plug Cleaning” in Chapter
05-30.
Clean the cable ends, spark plug
walls, and ceramics.
Refer to the section “Spark
Plug Cleaning” in Chapter
05-30.
Make sure that the spark plug
connections are tight.
Replace any broken, cracked,
deformed, or corroded parts.
Visually examine the ignition
leads for evidence of chafing or
deterioration per the “Ignition
Harness Inspection” procedure in
Chapter 74-20.
Replace any ignition leads
that are worn, damaged, or
broken. Refer to Chapter
74-20 for “Ignition Harness
Removal” and “Ignition
Harness Installation”
procedures.
Make sure that the ignition lead
mounting clamps are tight.
Tighten any loose clamps.