J.P. Instruments EDM 900 Pilots Guide - Manual (Page 29)

For Your Safe Flight Page 29
Leaning Rich Of Peak (ROP) Detection: Eventually, one cylinder
will reach peak before any of the other cylinders. The EDM will determine
this automatically. The EDM will indicate success in finding a peak by
displaying the word LEANEST for two seconds and flashing its
corresponding Cylinder column. The Scanner® Information Area will also
display the current value for the EGT on the left, and the fuel flow value
on the right, for final adjustment of the mixture, do not exit until the
leaning process is complete. The peak EGT value and Fuel Flow value
encountered during leaning is remembered by the EDM and can be
displayed by holding the PEAK button during Lean Find Mode.
Finalizing the Rich Of Peak Mixture: You may now enrichen the
mixture to operate at peak or continue enriching to a value of your choice
(typically between 50 to 100° rich of peak for best power), consistent with
the procedures defined in your aircraft and/or engine manual. Because
during the leaning process the mixture control was not stopped at the
exact time the column flashed the value shown will be 5 to 10 degrees on
the lean side. So as the mixture is enriched the temperature will go up to
peak and then down as the mixture is enriched further. Note: tap PEAK to
see the current difference from the peak temperature. This is handy for
finalizing mixture. Tapping EXIT exits the lean find mode and automatic
scanning resumes.
Column of Leanest
cylinder flashes
indicating the first
EGT to peak.
You are leaning
to Rich of Peak If you want to
lean Lean of
Peak press
button.
Fuel Flow will
go down then
up as one
enriches
mixture