EDM-790 Twin Engine Analyzer

This is a special order item. Please complete configuration worksheet here.


Part No:

Manufacturer: JP INSTRUMENTS

Taking the same easy-to-see color 4.5” x 3.3” display as the popular EDM900, the EDM-790 is the most versatile twin engine EGT/CHT analyzer on the market.

The EDM-790 will automatically find the first EGT to peak and will graphically display each cylinder EGT and CHT, while at the same time display those cylinder temperatures digitally. Aircraft voltage is also displayed digitally as well as optional TIT, OAT, and oil temperatures. The optional fuel computer will display gallons per hour for each engine, fuel used, fuel remaining, and time-to-empty, and when interfaced to a GPS you’ll see fuel needed to destination, nautical miles per gallon, and fuel reserve. The EDM-790 can monitor up to 29 channels of information with 14 columns of graphical information.

All the enhancements found on the single engine EDM-730 are included in the Twin engine EDM-790, including:


  • Digital display of OAT, TIT, OIL, CARB, IDA, CDT, and EGT/CHT
  • Shock Cooling displayed in degrees per minute with alarms
  • Normalize Mode levels the bar graph display for instant identification of engine trends during cruise
  • Automatically finds first cylinder to peak on each engine


EDM-790 is shipped complete including everything necessary for installation. The package contains:


  • JPI Quick response EGT probes
  • Bayonet CHT probes w/wiring harness
  • Insulating sleeves
  • Terminals w/mounting screws
  • Two year warranty on electronics
  • RS-232 Output port and one TIT function are included in system.


All EDM-790 systems come with data recording and provide long term trend monitoring to maintain ultimate engine health. Data Recording capability will record and store all displayed parameters and, at a later time, transfer the info to a palmtop or laptop PC. EDM-790 Data Recording contains a date and time clock. You may also program an aircraft ID, such as your aircraft registration number or your name that will appear in the output data file.

Fly your twin with the bright color (LCD) readout of our EDM760. Cost effective and compact, this advisory EDM has plenty of options to customize exactly what you require. The round rear processor is offset to allow easy horizontal installation in any panel. The Engine Data Management 790 system is the most advanced and accurate twin piston engine-monitoring instrument on the market. TSO’d for quality, the EDM 790 is not just another black box along for the ride. It is a Flight Engineer … a Maintenance Manager … For the price there is nothing that gets close to it. You can almost think of the EDM 790 as your personal flight engineer. It’s always there, working in the background, constantly watching over your engine while you concentrate on flying the aircraft. You can make an entire flight without ever pushing a button, if you so choose. Yet your EDM will be monitoring your engine parameters three times a second and will warn you instantly if any parameter exceeds the programmed limit.

Precision Diagnostics:

Accuracy and Resolution, are two of the most misunderstood terms in instrumentation. Because an instrument displays 1 degree increments (resolution) does


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° which has been verified and tested by the FAA and thus TSO’d (Technical Standard Order). the EDM is constantly “red-line” checking all 29 critical parameters (not 16) that are automatically checked FOUR TIMES A SECOND, regardless of current display status.

not mean it is accurate to 1 degree. JPI’s accuracy comes from its linearized thermocouples. Other’ put and estimating straight line through the center of the thermocouple calibration “S” curve. With this method the instrument is accurate at only three points along as the the straight line crosses the “S” curve. Therefore errors of +/- 10′ are quite possible while still displaying in 1degree resolution. Our competition is advertising +/- 1/2′ accuracy at full scale. This would mean that =/-1/2′ of 2000′ (full scale) is +/- 10′; there is a big difference. JPI has found nothing in the Aviation market that compares to our linearized accuracy.


Two buttons address ALL the programming functions of the EDM. 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.

Consider the Advantage:
Computer Assisted Diagnostics for troubleshooting entire system from the cockpit. Problem codes are displayed.
All programming done from the Front Panel, using two simple buttons.
29 Alarms, including EGT Differential, Alternator Voltage, Fuel Flow and Shock Cooling.
Variable Scaling of EGT Bar Graph.
LeanFind™ Mode automatically identifies the first and last cylinder to peak and PeakFind™ with quick responding probes, automatically captures the EGT or TIT peak value.
Data Port, True memory, is included FREE within each EDM (competition,s UBG-16 sells for $375 in a second add on box). This memory will permit down loading of data from the EDM to a laptop or Palm® computer. Palm® software is free on the JPI web site. Record interval is adjustable from 2 to 500 seconds or 25 to 1000 hrs. Records 26 functions not 16 like UGB-16. Record rate 2 to 255 seconds.
Fuel Flow option, the only graphic engine monitor with a complete fuel flow system. FAA approved for all EDMs including 9 cylinder Twins. This format frees up valuable panel space.
Resolution, all temperatures display in ONE degree ( note, even EGT) Pilot selectable to display in oC or oF. OAT option can be in oC or oF.
JPI’s well known “Grounded” fast response probes for quick accurate leaning. See Web page for results.
Shock cooling, cooling rate checked on each and every cylinder. Maximum cooling rate shown in degrees per minute. Dot over column identifies cylinder with highest cooling rate. The UBG-16 checks only ONE cylinder on a 6 cylinder engine.
Normalize Mode for accurate trend monitoring. Bars are in 10o increments.
Alphanumeric scanning display of 29 functions or channels not 16 like UGB-16.
Bus voltage Detects voltage loss due to alternator failure. IFR must. Free on all EDM’s Option on UBG-16
Oil temperature option in one degree increments and checked against an upper and lower limit.
TSO’d for Quality and Reliability with FAA, STC approved Fuel Flow. None of the competition is TSO’d. TSO quality permits JPI to offer a Three year Warranty.

EGT 4 or 6 probes
CHT 4 or 6 probes
Shock cooling
Span (highest to lowest EGT)
EGT Normalize mode
LOP/ROP function
Power connector
All required Harness 20 ft
EZTrends Graphing Software free
Serial Data recording -25 hours
3 year Warranty


FAA Approved under TSO-C43B, DO-160C, DO-178B Level C & STC, SA 2586 NM

Full Instrument: Width 4.81 Height: 3.47 Depth: 3.56

Insert Size 3-1/8 in panel mount 3.56 deep. Width Above Panel .80 Weight: 1 LB.

Standard Functions LeanFind, EGT/CHT, Shock Cooling, Voltage, Differential EGT, Normalize, Long term data module for Data Logging and TIT (if applicable for Engine).

Optional Functions Fuel Flow, Oil Temperature 1 & 2, Turbine Inlet 2 (TIT-2), Outside Air (OAT) and Carburetor Temperature (CRB).

LeanFind Mode:

automatically. JPI’s EDM-760 provides two methods of leaning: lean rich of peak (LEAN R) or lean of peak (LEAN L). With the advent of GAMI injector’s it is now possible to set the mixture lean of peak—saving fuel with a cooler running engine . The EDM 760 displays an inverted peak graph. Teledyne Continental has recommends 50oF lean of peak for the Malibu.

Leaning Rich of Peak:

Upon reaching cruise configuration, you can use the LF, LeanFind™ mode to identify the first cylinder to reach peak EGT. After cruise power has been established, pre-lean the mixture to about 50° rich of peak. Tap the LF, LeanFind™ button and simply lean. As you begin to lean the mixture, the EDM will check all cylinders using a proprietary algorithm looking for the first cylinder to achieve peak EGT. Do not lean slowly as required by other instruments. Lean aggressively and continuously as you normally do. The EDM will indicate success in finding a peak by displaying the words LEANEST for two seconds, followed by a 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 you hold the LF button. Notice that this cylinder is not necessarily the hottest EGT. JPI’s quick response, grounded, EGT probes permit the leaning process to take place quickly before there are major temperature changes. If you lean beyond peak, the EGT will drop and the engine will be operating lean of peak. The fuel flow option during LeanFind will simultaneously display fuel flow in Gal./Hr. and EGT. This will permit the pilot to enrichen the mixture while viewing the fuel that will be burned per hour. This is only possible with the JPI fuel flow with quick response fuel flow electronics.

Fuel Flow Option:

After extensive observations of many fuel flow measurement products, JPI’s engineers concluded that all the systems presently on the market were not capable of supporting the EGT leaning process due to their slow response times. JPI has developed a fast response system that permits you to simultaneously view peak EGT and minimum fuel flow. As the pilot leans the engine he will see simultaneously fuel flow and peak EGT. Enrichen the engine 20 degrees and note the fuel flow. There will be an optimum EGT enrichment vs. fuel flow for your engine, giving maximum range and power. The EDM Memory will include fuel flow in the data file. A throttle change with GPS interface will display fuel required to next GPS waypoint or destination. The EDM can be set to monitor EGT or Fuel Flow only or both sequentially with the flip of a switch. The bar graph always displays EGT/CHT .

Fuel Used (USD):

How much fuel has been used since you last refueled. This number will always become larger as fuel is consumed. You can instead show the fuel used on a long multi-fuel stop flight and we will see later in this video how to do that.

Fuel remaining (REM)

How much total fuel remains in the aircraft. Only total fuel remaining in the aircraft is calculated.

Hours and minutes remaining (H.M.):

Based on the current fuel flow rate, displays the remaining endurance time. This parameter is most meaningful during cruise. During sea-level climb the fuel flow rate will be almost twice that of cruise and the endurance indication will be about half of actual. On the other hand, during a power reduction descent, the endurance will indicate more time than is actually available when flying at cruise power.

Fuel Required to Waypoint/ Destination (REQ):

This parameter will be displayed only if your EDM 760 is receiving flight data from your GPS (this is a standard feature which is included with the Fuel Flow option). This will tell you how much fuel is required to get to the next waypoint or destination programmed on your GPS, based on your current fuel flow rate and present position.

Fuel Reserve (RES):

Fuel reserve when you arrive at your next waypoint. This parameter will be displayed only if your EDM 760 is receiving flight data from your GPS (this is a standard feature which is included with the Fuel Flow option). This will tell you how much fuel reserve you can expect when you arrive at your next waypoint or destination programmed on your GPS, at the current fuel flow rate.

Distance per fuel units. Both the REQ and the RES indicator lights will be on at the same time. It will tell you your miles per fuel unit such as miles per gallon, miles per liter or miles per pound. It is based on your current ground speed and current fuel flow rate.

See below for answers to our most popular questions.

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