J.P. Instruments EDM 740 Pilots Guide - Manual (Page 24)

Page 24 Engine Data Management
Lean of Peak leaning is as simple as:
A. Pre-lean your mixture.
B. Tap the LF button (verify LOP appears).
C. Lean mixture until RICHEST flashes (peak found).
D. Enrichen to the desired value ‘Lean Of Peak’.
L Procedure Scanner Example Comments
1 Establish cruise
between 65 to 75%
power.
2 Pre-lean the mixture to
50°F estimated rich of
peak on any EGT:
_________°F.
EGT
1491
CHT
391 *
See ‘Pre-leaning’
3 Wait one minute Let engine stabilize.
4 Tap the LF button LOP Start LeanFind (if ROP
appears, hold STEP & LF
until LOP appears)
5 Lean the mixture at
approx. 10°/second
without pausing.
(cylinder I.D. box
flashes when a EGT
rises 15°F)
EGT
1520 LF
(Without FF)
- or -
EGT
1520
FF
13.8
(With FF)
Flashing cylinder I.D. box
identifies the hottest EGT and
that an EGT has increased at
least 15°F which arms the
EDM to now look for first EGT
to peak.
6 After the first EGT
peaks, you will see
LEANEST for one
second and bars
coming from the top
down. Continue leaning.
EGT
-17 LF
(Without FF)
- or -
EGT
-17
FF
12.4
(With FF)
When bars come from the
top down, the steady cylinder
I.D. box identifies the first
EGT that peaked (leanest).
Continue leaning.
7 When RICHEST
appears, fine tune the
delta EGT to the
desired degrees below
‘Peak’ (Lean of peak).
EGT
-45 SET
(Without FF)
- or -
EGT
-45
FF
11.6
(With FF)
8 If you hold LF, the peak
EGT recorded will be
displayed along with FF
spread.
EGT
1560 PK
(Without FF)
- or -
EGT
1560
FF
0.6
(With FF)
Captured peak EGT value
and if FF equipped, the FF
spread between richest and
leanest cylinders.