Leaning Procedure - Textron Lycoming IO-540 Series Operator's Manual

TEXTRON LYCOMING OPERATOR'S MANUAL
SECTION 3
0-540 & 10-540 SERIES
b. See airframe manufacturer's instructions for recommended power
settings.
c. Fuel Mixture Leaning Procedure.
Improper fuel/air mixture during flight is responsible for many engine
problems, particularly during take-off and climb power settings. The pro-
cedures described in this manual provide proper fuel/air mixture when lean-
ing Textron Lycoming engines; they have proven to be both economical and
practical by eliminating excessive fuel consumption and reducing damaged
parts replacement. It is therefore recommended that operators, of all Tex-
tron Lycoming aircraft power-plants, utilize the instructions in this publica-
tion any time the fuel/air mixture is adjusted during flight.
Manual leaning may be monitored by exhaust gas temperature indica-
tion, fuel flow indication, and by observation of engine speed and/or
airspeed. However, whatever instruments are used in leaning the mixture,
the following general rules should be observed by the operator of Textron
Lycoming aircraft engines.
GENERAL RULES
Never exceed the maximum red line cylinder head temperature limit.
For maximum service life, cylinder head temperatures should be main-
tained below 435°F. (224°C.) during high performance cruise operation and
below 400°F. (205°C.) for economy cruise powers.
On engines with manual mixture control, maintain mixture control in
"Full Rich" position for rated take-off, climb and maximum cruise powers
(above approximately 75%). However, during take-offfrom high elevation air-
port or during climb, roughness or loss of power may result from over-richness.
In such a case adjust mixture control only enough to obtain smooth opera-
tion - not for economy. Observe instruments for temperature rise. Rough opera-
tion due to over-rich fuel/air mixture is most likely to be encountered at
altitudes above 5,000 feet.
Always return the mixture to full rich before increasing power settings.
Operate the engine at maximum power mixture for performance cruise
powers and at best economy mixture for economy cruise power; unless other-
wise specified in the airplane owners manual.