SECTION 3 LYCOMING OPERATOR’S MANUAL
OPERATING INSTRUCTIONS O-320 SERIES
a. Cold Engines.
(1) Perform pre-flight inspection.
(2) Set carburetor heat control in “off” position.
(3) Set propeller governor control in “Full RPM” position (where applicable).
(4) Turn fuel valves “On”.
(5) Move mixture control to “Full Rich”.
(6) Turn on boost pump.
(7) Open throttle approximately ¼ travel.
(8) Prime with 1 to 3 strokes of manual priming pump or activate electric primer for 1 or 2 seconds.
(9) Set magneto selector switch (consult airframe manufacturer’s handbook for correct position).
(10) Engage starter.
(11) When engine fires move the magneto switch to “Both”.
(12) Check oil pressure gage. If minimum oil pressure is not indicated within thirty seconds, stop
engine and determine trouble.
NOTE
If engine fails to achieve a normal start, assume it to be flooded and use standard clearing
procedure, then repeat above steps.
b. Hot Engines. Proceed as outlined above omitting the priming step.
4. COLD WEATHER STARTING. During extreme cold weather, it may be necessary to preheat the engine
and oil before starting.
5. GROUND RUNNING AND WARM-UP.
The engines covered in this manual are air-pressure cooled and depend on the forward speed of the aircraft
to maintain proper cooling. Particular care is necessary, therefore, when operating these engines on the
ground. To prevent overheating, it is recommended that the following precautions be observed.
NOTE
Any ground check that requires full throttle operation must be limited to three minutes, or
less if the indicated cylinder head temperature should exceed the maximum stated in this
manual.
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