Lycoming IO-390-D Series Installation And Operation Manual page 51

IO-390-D Series Engine Installation and Operation Manual
CAUTION
14. Move the throttle slowly and smoothly to the IDLE rpm.
WARNING
15. Look at the oil pressure gage for indicated pressure. If there is no oil pressure indication
within 10 seconds, stop the engine. Identify and correct the problems.
NOTICE: Unstable oil pressure or oil pressure less than 25 psi (172 kPa) could be an
indication of obstructed or interrupted oil flow or air in the oil lines. In this case,
stop, identify and correct the cause.
NOTICE: The engine is warm enough for take-off when the throttle can be opened without the
engine faltering.
Upon engine start, if smoke comes from a newly installed engine, after the first start,
there could have been some preservative oil in the cylinders, induction system,
and/or fuel nozzles/lines. If oil pressure is normal and the engine operates smoothly,
continue to operate the engine until the smoke clears. Otherwise, stop the engine and
identify the cause.
16. Let the engine operate at 1000 rpm for approximately 3 minutes.
17. Complete a magneto drop-off check as follows for all three cycles RIGHT/LEFT/BOTH.
A. Operate the engine at approximately 2100 to 2200 RPM.
NOTICE: To prevent spark plug fouling, do not operate on a single magneto for too long a
period. A few seconds is usually sufficient for the magneto drop-off check.
B. Switch from BOTH magnetos to one magneto and note the drop-off; return to BOTH
until the engine regains speed and switch to the other magneto and note the drop-off, then
return to BOTH. Drop-off must not exceed 175 rpm and must not exceed 50 rpm between
magnetos.
C. If the rpm drop exceeds 175 rpm, slowly lean the mixture until the rpm peaks. Then
retard the throttle to the specified rpm, for the magneto drop-off check and repeat the
check. If the drop-off does not exceed 175 rpm and the difference between the drop-off
values for both magnetos does not exceed 50 rpm, and the engine is running smoothly,
the ignition system is operating properly.
D. Smooth operation of the engine with a drop-off that exceeds the specification of 175 rpm
is usually an indication of a propeller load condition at a rich mixture.
18. Look for any illuminated caution or warning lights in the cockpit.
© 2020 Avco Corporation. All Rights Reserved
March 2020
COMPLETE SMOOTH AND STEADY FULL RANGE THROTTLE
MOVEMENTS IN 2 TO 3 SECONDS. FULL RANGE THROTTLE
MOVEMENT IN LESS THAN 2 SECONDS IS TOO RAPID AND CAN
CAUSE SUBSEQUENT ENGINE DAMAGE.
DO NOT OPERATE THE ENGINE IF THE OIL PRESSURE IS LOW. IF
THE ENGINE IS OPERATED AT LOW OR NO OIL PRESSURE, THE
ENGINE CAN MALFUNCTION OR STOP.
Engine Initiation
Page 31