CIRRUS DESIGN SR20, Pilot Operating Handbook

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4-20 P/N 11934-003
Section 4 Cirrus Design
Normal Procedures SR20
Cruise Leaning
The engine is equipped with an altitude compensating fuel pump that
automatically provides the proper full rich mixture. Because of this, the
mixture should be set to full rich to allow the aneroid to provide auto
leaning for the engine during all flight conditions. If additional cruise
leaning beyond that provided by the aneroid is desired, be advised
that there may not be a 75° temperature rise from full rich to peak. This
is acceptable provided the airplane is at 75% power or less and engine
temperatures are within limits.
• Caution •
If moving the mixture control from the full rich position only
decreases the EGT from the full rich value, place the mixture
control back in the full forward position and have the fuel
system serviced.
• Note •
Serials 1337 thru 1581 with SRV standard configuration: The
airplane is not equipped with an EGT/CHT gage. To lean the
engine for cruise, pull the mixture lever towards CUTOFF until
engine runs rough and then push the mixture lever towards
FULL RICH until engine operation smooths out.
Exhaust gas temperature (EGT) may be used as an aid for mixture
leaning in cruise flight.
For “Best Power” use 75% power or less.
For “Best Economy” use 65% power or less
. To adjust the mixture,
lean to establish the peak EGT as a reference point and then adjust
the mixture by the desired increment based on the following table
:
Under some conditions, engine roughness may occur while operating
at best economy. If this occurs, enrich mixture as required to smooth
engine operation. Any change in altitude or Power Lever position will
require a recheck of EGT indication.
Mixture Description Exhaust Gas Temperature
Best Power 75° F Rich Of Peak EGT
Best Economy 50° F Lean Of Peak EGT
Revision A5