IO-390-D Series Engine Maintenance Manual
72-00
© 2020 Avco Corporation. All Rights Reserved
Page 104
March 2020
IO-390-D Series Engine Maintenance Manual
4.
Operational Ground Check
NOTICE:
The purpose of this check is to make sure the installed engine operates in the aircraft
according to specifications in Appendix A of the
IO-390-D Series Engine Installation
and Operation Manual
.
A.
Per the component manufacturer's instructions, calibrate the cylinder head temperature gage,
oil temperature gage, oil pressure gage, manifold pressure gage, and tachometer prior to
testing.
B.
Make sure that all of the engine gages operate correctly.
C.
Make sure that the vent and breather lines are correctly installed and secured in accordance
with the aircraft manufacturer’s instructions.
D.
Install the cowling and all of the aircraft baffles per the aircraft manufacturer’s instructions.
E.
Position the aircraft into the wind.
F.
Complete the applicable procedures in either the “Engine Initiation” chapter or “Engine
Operation” chapter of the
IO-390-D Series Engine Installation and Operation Manual.
NOTICE:
Engine initiation procedures are to be done in the field on any of the following
newly installed Lycoming engines:
•
Any new, overhauled, or rebuilt engine from the factory and field-overhauled engines
•
Engine taken out of storage (if not run-in when put in storage)
•
An engine which has been disassembled/re-assembled
5.
Idle Speed and Mixture Adjustment
NOTICE:
The fuel injector servo has a speed
adjustment screw to adjust the idle
speed. Refer to Figure 2. There is
also a mixture adjustment wheel on
the throttle body to adjust the idle
mixture. Refer to Figure 2.
NOTICE:
The goal of this procedure is to
adjust the idle speed and mixture to
an optimum level.
A.
Start the engine and operate it until the oil
and cylinder head temperatures are in the
specified operating range shown in
Appendix A of the
IO-390-D Series
Engine Installation and Operation
Manual
.
Figure 2
Speed Adjustment Screw and Mixture
Adjustment Wheel on the Fuel Injector Servo
B.
Set the throttle stop screw to let the engine idle at idling rpm speed.
NOTICE:
As needed, set fuel controls on new, rebuilt, or overhauled engine to 50 to 100 rpm
higher than usual idle speed (600 to 700 rpm) for the first 25 hours of operation -
then adjust to the usual setting after the first 25 hours of operation.
