J.P. Instruments EDM-700 Manual

Pilot’s Guide
Engine Data Management
EDM-700
EDM-800
EDM-711 Primary
Copyright 2000-2007 J.P. Instruments, Inc.
All Rights Reserved
J.P. INSTRUMENTS INC.
Information: P. O. Box 7033
Huntington Beach, CA 92646
Factory: 3185 B Airway Avenue
Costa Mesa, CA 92626
[phone] [phone]
Fax [phone]
www.jpinstruments.com
[email protected]
Printed in the United States of America Rev X 11/2017
Last printed 11/13/2017 3:30:00 PM

Table of Contents
Section 1 - Introduction 1
Product Features 1
Engine Data Management 2
Benefits of Proper Mixture Control 2
JPI Probes 2
Temperature and Mixture 2
Section 2 - Displays and Controls 4
Displays 4
Modes 7
Buttons 8
Parameter Scan— EDM-700 without Fuel Flow Options 9
Automatic Parameter Scan—EDM-711 10
Section 3 - Operating Procedures 11
Diagnostic Testing on Startup and During Flight 11
Modes 11
Automatic Mode 11
Manual Mode 12
LeanFind Mode—Leaning Rich of Peak 12
LeanFind Procedure—General Explanation 14
Operation for each Phase of Flight 18
Shock Cooling 19
Common Misapplications 20
Section 4 - Diagnosing Engine Problems 21
Alarms 24
Pre-Ignition and Detonation 25
Section 5 - Fuel Flow Option Operation 26
Fuel Flow Display Select Switch 26
Fuel Management 28
Parameter Scan—Systems with Fuel Flow Option 28
Section 6 - Long Term Data Memory 30
Downloading from Long Term Memory 31
Downloading Data from the EDM to a Flash Drive 31
Downloading from USB Flash Drive to a PC 33
Section 7 - Personalizing 33
Pilot Programming 33
Section 8 - Programming the EDM-800 Horsepower Constant 36
Section 9 - Programming Manifold Pressure (MAP) 36
Section 10 - Programming use of Factory Original TIT Probe 37
Section 11 - Programming the Fuel Flow Option 39
Fuel Flow Option Programming Procedure 41
Section 12 - Programming Long Term Data Memory 41
Section 13 - EDM-711 Primary Alarm Display 42
Section 14 - Alarm Limits 43
MAP, Fuel Flow Alarm Limits, Units, Fuel Capacity 45

Navigation Data Formats 47
GPS-C Fuel Flow Format for GPS Bi-directional Comm 47
Diagnostic Messages, Fuel Flow 48
Navigation Data Ports for GPS Comm 48
Section 15 - Option Connector Pin Assignments 50
Section 16 - Reference Reading 51
Section 17 - Technical Support 51
Limited Warranty 52
Index 53




HowtoChangeModes(page 7)
EDM-700 enters Automatic mode two minutes after power up
AUTO INDEX
parameters
automatically
indexed
MANUAL INDEX
parameters
indexed when
step in tapped
Toggle to include/
exclude
parameter in
indexing
LEAN FIND
starts LeanFind
procedure
Toggle between
LEAN R and
LEAN L of peak
dot flashes see
LEANEST
Displays
peak EGT
value
tap STEP button
tap LF, then tap STEP
tap STEP and
LFsimultaneously
release buttons
LF
LF
STEP
hold bothSTEP
and LF
simultaneously
begin
leaning
continue
leaning hold LF
release
LF
In Lean of peak, after first
LeanFind, LF will return to the
inverted bar graph. Tap LF again to
start LeanFind procedure

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Section 1 - Introduction
Product Features
indicates standard feature 700 711 800
Hands-free, automatic scanning (711: primary only) 
All programming done from the Front Panel 
LeanFindfinds the first and last cylinder to peak
with true peak detect—eliminates a false peaks

Displays both leaned temperature below peak and peak 
Battery voltage with alarm 
24 Programmable alarm limits 
Normalize view 
DIF low to high EGT with alarm 
EGTs to stable 1°F resolution 
Shock cooling monitored on every cylinder 
User selectable index rate 
Fast response probes 
Non-volatile long term memory 
Records and stores data up to 30 hours 
Post-flight data retrieval 
Data retrieval software 
FAA Approved as primary temperature instruments for
CHT, OIL, TIT 
Alarm and warning light panel 
Oil Temperature opt opt
Oil Pressure opt opt opt
Turbine inlet temperature opt opt opt
Outside air temperature opt opt 
Compressor discharge temperature opt opt opt
Carburetor temperature opt opt opt
Fuel Flow FF opt FF opt 
Solid-state rotor fuel flow transducer FF opt FF opt 
Fuel quantity in gallons, kilograms, liters, or pounds FF opt FF opt 
Low fuel quantity alarm FF opt FF opt 
Low fuel time alarm FF opt FF opt 
GPS interface FF opt FF opt 
Instantaneous fuel flow rate FF opt FF opt 
Total amount of fuel consumed FF opt FF opt 
Total fuel remaining FF opt FF opt 
Time to empty at the current fuel flow rate FF opt FF opt 
Displays % horsepower and RPM RPM opt RPM opt 
Automatically calculates percent horsepower 

Page2EngineDataManagement
Engine Data Management
The EDM Engine Data Management system is the most advanced and
accurate piston engine-monitoring instrument on the market. Using the
latest microprocessor technology, the EDM will monitor up to twenty-
four critical parameters in your engine, four times a second, with a
linearized thermocouple accuracy of better than 0.1 percent or 2 F°.
As your built-in flight engineer, the EDM is constantly “red line”
checking: all critical parameters are automatically checked four times a
second, regardless of the current display status. Leaning is accomplished
quickly and automatically using the LeanFindprocedure. With the
EDM it is now possible to have substantially more diagnostic
information available to you in a timely and usable manner.
The real-time serial data port—a standard feature—permits you to record
scanned parameters in real-time using a user-supplied laptop PC.
Benefits of Proper Mixture Control
Improved engine efficiency Reduced maintenance costs
Greater fuel economy Reduced operating costs
Smoother engine operation Proper engine temperatures
Longer spark plug life Reduced engine vibration
JPI Probes
Temperature information
processed by the EDM is captured
by fast response, grounded JPI
temperature probes, that accurately
measure the small temperature
changes—as small as 1°F—that
occur during mixture adjustment.
Temperature and Mixture
In a piston engine only a small portion of the energy from combustion
produces movement of the piston during the power stroke. The majority
of energy passes into the exhaust pipe as hot gasses. By monitoring the
temperature of these exhaust gasses you will have an indication of the
quality of the combustion process. Low compression, non-uniform fuel
distribution, faulty ignition, and clogged injectors diminish the efficiency
of the combustion process that generates power.
CHT probe
EGT probe
cylinder
head exhaust manifold

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From the cockpit you can adjust the fuel/air ratio by a process called
leaning. Retarding the mixture control changes the fuel/air ratio and
hence the resulting Exhaust Gas Temperature (EGT).
The following figure depicts the mixture and temperature relationship.
EGT °F below peakPercent of best power
CHT °F change from
best power
Best
power
range
0
-100
-50
-20
20
-60
-40
0
-80
100
85
90
95
80
Percentpower
Specificfuel consumption
Too
lean
Lean
Rich
Full Rich
(Take-off)
EGT
CHT
First cylinder to
peak. Use for
Rich of Peak
leaning
Last cylinder to
peak. Use for
Lean of Peak
leaning with GAMI
injectors
Peak Power
Best
economy
range
GAMI
spread
As the mixture is leaned, EGT rises to a peak temperature, and then
drops as the mixture is further leaned. Peak power occurs at a mixture
using more fuel than at peak EGT. Best economy occurs at peak EGT.
Accurate leaning yields optimal engine temperatures. By being able to
precisely adjust the mixture, your engine can produce either the best fuel
economy or maximum power, whichever you choose.

Page4EngineDataManagement
A single EGT gauge merely gives you an average of each cylinder’s
temperature: some cylinders can be too rich, while others too lean.
Variations produced by differences in fuel distribution, ignition, and
compression will cause each cylinder to follow its own mixture and
temperature relationship such that one cylinder will reach peak before
another.
Section 2 - Displays and Controls
The EDM monitors engine temperatures and voltages, assists in adjusting
the fuel/air mixture, and helps diagnose engine malfunctions. There are
three components of the user interface:
Analog display including cylinder number and index dot
Digital display for numeric readouts and messages
Two front panel operating buttons.
Displays
I340 376
STEP LF
1 2 3 4 5 6 T
73
HP
NRM F
EDM 800
J
PI
_
EGT
%
Limit
_
250
350
450
CHT
TSO






°F or °C
Dash line or
NRM indicates
Normalize or
Percent view
Cylinder
numbers 1
through 6. T is
TIT otherwise
oil temp
Exhaust Gas
Temperature
(EGT) is the top of
the column
Percent
HP
or RPM
(EDM-
800 only)
Dot indicates which
cylinder temperatures
are shown in the
digital display
Cylinder Head
Temperature
(CHT) is shown
as a missing
segment
Maximum
line is the
EGT, TIT
and OIL
redline
CHT
absolute
scale

Systems with
both TIT and
OIL, OIL is
shown as
missing segment
Analog Display
The upper half of the face of the EDM is the analog display with %HP.
The following is a description of the analog display, from top to bottom.
Numbers in circles refer to features in the above diagram.

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 Normalize and Percentage View Indicators
Percentage view: when there is a dash — near the Pat the top of
the display (EDM-700) or NRM is not lighted (EDM-800), the
columns indicate percent of EGT red line. Each column is
composed of a stack of segments. A maximum height column
depicts 100 % of red line and a one segment-high column depicts
50 % of red line. For example, if the red line is 1650°F, a
maximum height column represents 1650°F and a one segment-
high column represents half that value, or 825°F. The
Percentage view permits comparison of EGTs across all
cylinders. Hotter cylinders display higher columns than cooler
cylinders.
Normalize view: when there is a dash _ near the Nat the top of
the display (EDM-700) or the letters NRM are lighted on the left
side (EDM-800), the EGT columns are displayed normalized.
When you change to the Normalize view, all column peaks are
set to the same half-height level for trend analysis. Any changes
are shown as an increase or decrease in column height. A one-
segment change in column height represents a 10°F change.
The Normalize view permits rapid visualization of EGT trends,
rather than a percentage of red line. You should use normalize in
level cruise and run-up.
To toggle between Percentage and the Normalize views, hold the LF
button for five seconds until the display changes. The analog display
becomes half height and the display changes to the Normalize view.
Selecting the Normalize view does not affect the digital display nor alter
the parameter sequence. The CHT display—described later—is not
affected by the Normalize or Percentage view.
You may select the Normalize view in either the Manual or Automatic
mode. Normalize view is most helpful for engine trend monitoring of
each cylinder’s operation. For example using the Normalize view during
engine run-up, a fouled spark plug will appear as a higher column.
A common misapplication is to be in the Normalize view and then
change your power setting, causing all columns to go off scale, high or
low. Set to the Percentage view before adding or reducing power.
Always set Percentage View when beginning your descent.
 Temperature Units (°F or °C)
°F temperatures in the digital display are in Fahrenheit degrees.
°C temperatures in the digital display are in Celsius degrees.

Page6EngineDataManagement
To change the display of engine temperatures see “Changing the
Alarm Limits” on page 43.
 Cylinder Numbers and Dot Index
A row of numbers 1through 6and the letter Tare the column labels for
the analog display. The 1through 6are the cylinder numbers. If the TIT
option is installed, the Tdenotes the last column is displaying Turbine
Input Temperature (TIT) as a column. If the Tis absent and the Oil
temperature option is installed, the last column displays Oil temperature.
If both TIT and Oil temperature options are installed, the last column
displays TIT and the missing segment displays Oil temperature. The
highest Oil temperature segment will flash only when the digital display
shows OIL. The highest TIT segment will flash on when the digital
display shows TIT. A round dot under the numbers 1 through 6 indicates
that particular column is shown numerically in the EGT and CHT digital
display.
 Bar Graph EGT and CHT
Each column in the bar graph is composed of a stack of segments. The
total height of each column represents the EGT and the missing segment
in the column represents the CHT.
In the Percentage view, the EGT, TIT, and Oil temperature
resolutions depend on the programmed red line limits.
CHT is displayed by a missing segment and
should be interpreted as follows: a missing
segment corresponds to the CHT in 25 F°
increments, starting at 250°F at the bottom. In
the example shown here, the CHT is 300°F. If the EGT bar
is lower than the missing CHT segment, then the CHT will
be indicated by a single isolated lighted segment.
The CHT display is the not affected by mode or view.
 Percent HP (EDM-800 only)
Displays percent of rated HP or RPM depending on pilot programming.
Digital Display
Beneath the bar graph is the 9-segment alphanumeric display.
EGT and CHT
When the dot index is beneath a cylinder number, 1 through 6, the digital
display shows the EGT on the left (four digits) and the CHT on the right
(three digits). Other parameters are displayed in the digital display as
250
350
450
CHT

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described in the subsection “Parameter Scan— EDM-700 without Fuel
Flow Option” on page 9. The EDM-711 will briefly display EGT –
CHT before displaying the numerical values.
I340 376
STEP LF
1 2 3 4 5 6 T
73
HP
NRM F
EDM 800
J
PI
_
EGT
%
Limit
_
250
350
450
CHT
TSO
4 digit
display of
EGT 3 digit
display of
CHT
Display Dimming
The entire display panel features automatic dimming. Allow ten seconds
for the display to adjust to ambient lighting conditions.
Modes
There are three standard operating modes of the EDM: Automatic,
Manual, and two LeanFind submodes. These modes will be described in
more detail beginning on page 11. Most of the time you will operate the
EDM in the Automatic mode. When you first turn on the power the EDM
starts in the Manual mode, but will enter the Automatic mode after two
minutes. The three modes affect primarily the digital display.
Automatic Mode
Just tap the LF button, then tap the STEP button. No user
intervention is required to use this mode. Each cylinder and each
parameter value is automatically sequenced and shown in the digital
display for a few seconds. The EDM-711 will automatically scan only
the primary temperatures: highest CHT, TIT, OIL.
Manual Mode
Just tap the STEP button. Automatic stops. Each indexed parameter is
frozen in the digital display until you manually index to the next
parameter by tapping the STEP button. The EDM-711 will manually
scan all parameters.

Page8EngineDataManagement
LeanFind Mode
Simply pre-lean, tap the LF button and begin leaning. The EDM will
assist you in finding the first cylinder to peak.
Buttons
I340 376
STEP EDM-700 LF
JPI
STEP button LF button
Buttons, Front Panel
Two operating buttons control all functions of the EDM.
The term tap will be used to denote pressing a button momentarily. The
term hold will be used to denote pressing and holding a button for five
seconds or longer.
STEP Button
Located on the lower left side near the instrument face.
In the Automatic mode, tapping the STEP button will stop
and change to the Manual mode. Then each tap of the STEP
button will display the next parameter in the sequence.
In the LeanFind mode tapping the STEP button will
terminate the LeanFind mode and change to the Automatic
mode.
Secondary functions of the STEP button include:
In the Manual mode holding the STEP button will display the previous
parameters in the sequence (rapidly backwards).
In the programming procedures, tapping the STEP button will advance to
the next item in the list.
When an alarm is displayed, tapping the STEP button will temporarily
delete that alarm from appearing for the next ten minutes.
When an alarm is displayed, holding the STEP button until the word OFF
appears will delete that alarm from appearing for the remainder of the
flight.
LF Button
Located on the lower right side near the instrument face.

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In Automatic or Manual modes, tapping the LF button will
change to the LeanFind mode.
In Automatic or Manual modes holding the LF button for
three seconds will toggle between Percentage and Normalize
views.
N: Normalize viewP: Percentage view
hold LF button
for 3 seconds
In the LF mode holding the LF button after peak EGT is
found will display peak EGT.
Secondary functions of the LF button include:
In the pilot programming procedure, holding or tapping the LF button is
used to increment or decrement parameter values and toggle between Yes
and No answers to questions.
STEP and LF Buttons
Holding both the STEP and LF buttons simultaneously for
five seconds changes to the pilot programming procedure.
Holding both the STEP and LF buttons simultaneously for
five seconds after entering LeanFind mode but before
beginning to lean will toggle between leaning “rich of peak”
and “lean of peak.”
Tapping both the STEP and LF buttons simultaneously in
Manual mode toggles to include or exclude the displayed
parameter from the Automatic mode. It has no affect on the
displayed parameters in the Manual mode.
In the LF mode tapping both the STEP and LF buttons
simultaneously will mark a data record in long term
memory and display will flash SNAP.
Parameter Scan— EDM-700 without Fuel Flow Options
The EDM steps through the engine parameters in a specific sequence.
Listed below is the sequence, parameter description and example of the
digital display.

Page10EngineDataManagement
Parameter Example Comments
Voltage, System Bus I4.2 BAT Battery voltage
Outside Air Temperature 8I
OAT °F or °C
Induction Air
Temperature I25
IAT Out of the intercooler
Compressor Discharge
Temperature 300
CDT Into the intercooler
Carburetor Temperature -22 CRB Not available when CDT is
installed
Difference between
hottest and coolest EGT 80 DIF Dot indicates most widely
deviating cylinder
EGT, CHT I340
376 EGT, left, CHT, right. Dot
indicates cylinder
TIT, Turbine Inlet
Temperature TIT
TI2 Turbine #1, left shows as
column.
Turbine #2, right
Oil Temperature I78
OIL Missing bar in TIT column or is
column
Oil Pressure 90 O-P Only available as an option or
in the EDM-830
Shock Cooling -30 CLD Dot indicates fastest cooling
cylinder
The display will pause at each parameter for four seconds in the
Automatic mode. (The four second pause time can be changed.) In the
Manual mode, tap the STEP button to advance to next parameter. Only
the parameters for the options that are installed will be displayed;
uninstalled parameters will not appear.
Automatic Parameter Scan—EDM-711
The EDM-711 in automatic scan mode will display only the following
three primary temperatures: highest CHT, OIL and if the option is
installed, TIT.

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Section 3 - Operating Procedures
Diagnostic Testing on Startup and During Flight
When your EDM is first turned on, all digits light up for a few seconds,
permitting you to check for non-functional segments. Then each column
is self-tested in sequence while the EDM tests internal components,
calibration and integrity of the probes. If a problem is found, it will be
displayed as OPEN PRB or CAL ERR,followed by the name of the
probe or channel.
Display Channel Display Channel Display Channel
EGT I EGT #1 CHT I CHT #1 OIL Oil
EGT 2 EGT #2 CHT 2 CHT #2 TIT I TIT #1
EGT 3 EGT #3 CHT 3 CHT #3 TIT2 TIT #2
EGT 4 EGT #4 CHT 4 CHT #4 CDT CRB CDT carb
EGT 5 EGT #5 CHT 5 CHT #5 IND IAT
EGT 6 EGT #6 CHT 6 CHT #6 OAT OAT
During flight, probes are constantly checked for inconsistent or
intermittent signals. A faulty channel or probe encountered during start-
up or during flight will be deleted from the sequence, producing a
missing column or blank digital data.
Modes
The EDM has three different operating modes: Automatic, Manual and
LeanFind. When you first turn on the power the EDM starts in the
Manual mode, but will enter the Automatic mode after a few minutes.
The Automatic mode provides you with engine monitoring information
for the majority of flight conditions. To adjust the mixture, use the
LeanFind mode. And to display specific parameters, use the Manual
mode. In both the Automatic and Manual modes the analog display
shows a bar graph of EGT and CHT for each cylinder and the TIT and
Oil temperature.
Automatic Mode
Just tap the LF button, then tap the STEP button. No user
intervention is required to use this mode. In the Automatic mode the
EDM displays the parameter sequence at a user-selected rate (see
“Personalizing” on page 33).
Individual parameters can be excluded from the Automatic mode
(exclusion does not apply to the EDM-711): tap STEP to enter the
Manual mode. Tap STEP to index to the parameter you want to exclude.
Then tap both the STEP and LF buttons simultaneously. Excluded

Page12EngineDataManagement
parameters display a decimal point before the parameter name. For
example:
Included: I84 OIL Excluded: I84 .OIL
Tapping the STEP and LF buttons simultaneously will toggle back and
forth between include and exclude.
Every time you turn on the EDM, all parameters are reset to be
included.
All installed parameters are always displayed in the Manual mode.
Exclusion only applies to the Automatic mode.
All parameters are checked for alarm conditions every second
regardless of their included or excluded status.
Manual Mode
Just tap the STEP button. Use the Manual mode when you want to
monitor one specific parameter such as shock cooling during descent, or
a particular cylinder temperature during climbs. To change to the Manual
mode, tap the STEP button once. Subsequent taps will index the digital
display through the parameter sequence (see “Parameter Scan— EDM-
700 without Fuel Flow Option” on page 9). To exit the Manual mode and
return to the Automatic mode, either tap the LF button and then tap the
STEP button—see “How to Change Modes” in the front of this manual.
You may disable the Automatic mode by setting “0” for scan rate
(disabling Automatic mode does not apply to EDM-711).
LeanFind Mode—Leaning Rich of Peak
JPI’s EDM-700 and EDM-800 provide two methods of leaning: lean
rich of peak (LEAN R)or lean of peak (LEAN L). The standard
method is to lean about 20° rich of peak. With the advent of GAMI
injectors it is now possible to set the mixture lean of peak—saving fuel
and running the engine cooler. Teledyne Continental recommends lean of
peak for the Malibu. This manual primarily describes the rich of peak
method, and provides the procedure for the lean of peak method. The
default method is set to rich of peak.
Simply pre-lean, tap the LF button and begin leaning. Upon reaching
cruise configuration, you will use the LeanFind mode to identify the first
cylinder to reach peak EGT.
LeanFind Procedure—Step-by-Step
Procedure Example Comments

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1 Establish cruise at approx.
65 to 75% power.
2 Pre-lean the mixture to 50°F
estimated rich of peak EGT
on any cylinder: _____°
I490
370 *For your first flight with the
EDM, use the method shown
below.
3 Wait one minute Let engine stabilize.
4 Tap the LF button LEAN
R Start LeanFind. (Optionally to
change to “lean of peak”
method, hold both STEP and
LF simultaneously.)
5 Lean the mixture—approx.
10°/second without pausing—
while observing the display.
When there is a 15°F rise in
EGT, LeanFind mode
becomes active.
I520
LF
Without FF
I520
I3.8
With FF
Flashing cylinder DOT
indicates hottest cylinder and
that LeanFind mode is active.
6 Stop leaning when
a column begins flashing.
You will see LEANEST for two
seconds, followed by:
I545
SET
or with
Fuel Flow
I545
I 2.4
Flashing cylinder dot &
column indicates leanest
cylinder. (SET means Set the
mixture.) Due to thermal
inertia this will usually be
about -15°F lean of peak.
7 If you hold LF, peak EGT will
be displayed while the LF
button is held down.
I560
PK Captured peak EGT value is
displayed.
8 Slowly enrich the mixture. the
temperature will increase,
returning to peak.
Stop enriching at the desired
EGT. Best economy
Best power
I560
SET
I560
SET
I460
SET
Peak EGT for best
economy
100° rich of peak for best
power
Best
power Temperature when
column flashes
best economy
leaner
richer
9 If you have chosen the Lean
of Peak method, at step 5
continue leaning until the last
cylinder has peaked.
-I5
SET
OR
-I5
I2.3
Only for GAMI injected
engines. When each cylinder
reaches peak, the cylinder
number will begin flashing.
*Determining the pre-lean value: while in cruise at under 65 percent
power, choose any cylinder and lean that cylinder to peak EGT in the
Manual mode or to engine roughness, whichever occurs first. Note the
peak, subtract 50° and write the resulting number in the space provided
in step 2.

Page14EngineDataManagement
LeanFind Procedure—General Explanation
Lycoming and Continental engines have established specific
restrictions on leaning that must be followed, such as
percentage of power, climb leaning, and TIT limits. Lycoming
recommends operation at peak EGT for power settings of 75%
or lower, while Continental recommends operation at peak
EGT for power settings of 65% or lower. This guide is not
meant to supersede any specific recommendations of the
engine manufacturer or airframe manufacturer.
It is your responsibility to know your aircraft’s limitations.
Pre-lean the mixture to about 50° below peak. After pre-leaning, wait for
one minute for the temperatures to stabilize. Next, begin the leaning
process by tapping the LF button. This tells the EDM to begin looking
for a 15° rise in EGT for any cylinder. Begin leaning the mixture without
pausing. When a 15° rise occurs, eliminating false peaks, the LeanFind
mode becomes activated shown when the cylinder dot above the column
of the hottest cylinder begins flashing. The LeanFind mode is not
active until a cylinder dot is blinking.
With the Fuel Flow Option, instead of seeing the word LF in
the display, you will see numerical fuel flow rate during the
leaning process on the right side of the digital display, for
example I2.4. This allows you to observe the EGT rise and at
the same time watch the fuel flow rate decrease.
To show the progress of the leaning process, the EDM selects the hottest
cylinder for reference in the digital display. In the example below, the
I360 is the current temperature of the hottest cylinder.

ForYourSafeFlightPage15

I360 LF
STEP EDM-700 LF
° F
1 2 3 4 5 6 T
N P
J
PI
_
_
EGT
%
Limit
_
300
400
500
CHT
TSO
number of
hottest cylinder
flashes when
EGT rises 15°
dot
indicates
hottest
cylinder
temperature
and "LF"
displayed
When LF is activated:
Continue leaning slowly without pausing. With a vernier mixture control,
turn the knob about a quarter turn every second. With a non-vernier or
quadrant mixture control, lean slowly and smoothly about 1/16 inch
every five seconds. Eventually, one cylinder will reach peak before any
of the other cylinders. The EDM will determine this automatically.
Notice that this cylinder does not necessarily have the hottest EGT.
The EDM will indicate success in finding a peak by displaying the words
LEANEST for two seconds, followed by flashing the column and
displaying the value of the EGT of the cylinder that peaked first. The
word SET will also be displayed. (With the Fuel Flow Option the current
fuel flow rate will be displayed on the right side of the digital display
instead of the word SET.) The flashing cylinder will be locked—or set—
into the digital display during the remainder of the LeanFind procedure
to allow you to set the final mixture. The peak EGT value is remembered
by the EDM and will be displayed as long as you hold the LF button.
You may now enrichen the mixture to operate at peak or continue
enriching to 100° rich of peak, or a value of your choice, consistent with
the procedures defined in your aircraft engine manual.
If you lean too much, the EGT will drop and the engine will be operating
lean of peak.

Page16EngineDataManagement
I340 SET
STEP EDM-700 LF
° F
1 2 3 4 5 6 T
N P
_
J
PI
_
LEANEST
LEANEST
displayed for
two seconds
when peak is
found
Leaning Rich of Peak
_
EGT
%
Limit
_
250
350
450
CHT
TSO
Cylinder
number of the
LEANEST
cylinder flashes
Dot indicates
LEANEST
cylinder
Column of the
LEANEST
cylinder flashes
EGT of the
LEANEST cylinder
displayed with the
the word SET
Lean of Peak Leaning with GAMI injectors
To use the “lean of peak” method, tap LF and then immediately hold
both STEP and LF until you see LEAN L. Once you begin leaning
(flashing dot) you cannot change leaning methods. You may toggle back
to LEAN R by holding both buttons again.
Leaning Lean of Peak
-5 7.3
73
HP
1 2 3 4 5 6 T
_
STEP LF
EDM 800
J
PI
_
EGT
%
Limit
_
300
400
500
CHT
TSO
Cylinder number
flashes when the
cylinder peaks
Temperature
below peak of
last cylinder to
peak
Shortest
column is
the last
cylinder to
peak
Current fuel
flow rate
First cylinder to
peak has
largest column
Hold LF to see
peak
temperature of
last cylinder to
peak (e.g.
I340 )
Hold LF to see
GAMI spread
(delta fuel flow)
In the “lean of peak” method the columns will invert with the first to
peak progressing down from the top of the display. The inverted column
scale is 5° per segment below peak. As you continue to lean past peak
the dot of the each successive cylinder will flash as it peaks. The peaks