J.P. Instruments EDM 740 Pilots Guide User Manual
Page 23
For Your Safe Flight
Page 23
Rich of Peak leaning is as simple as:
A. Pre-lean your mixture.
B. Tap the LF button (verify ROP appears).
C. Lean mixture until LEANEST flashes (peak found).
D. Enrichen to the desired value ‘Rich Of Peak’.
R
Procedure
Scanner Example
Comments
1
Establish cruise at 65
to 75% power.
2
Pre-lean the mixture
to 50°F estimated
rich of peak on any
EGT: _________°F.
EGT
1490
CHT
370
*
See ‘Pre-leaning’
3
Wait one minute
Let engine stabilize.
4
Tap the LF button
ROP
Start LeanFind (if LOP
appears hold STEP & LF until
ROP 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
Stop leaning when
a column begins
flashing. You will see
LEANEST
for one
second, followed by:
EGT
1545 SET
(Without FF)
- or -
EGT
1545
FF
12.4
(With FF)
Flashing cylinder I.D. box
AND its column indicates
leanest cylinder. (SET means
Set the mixture.) Due to
thermal inertia this will usually
be about -15°F down the lean
side of peak.
7
If you hold LF, peak
EGT will be displayed
while the LF button is
held down.
EGT
1560 PK
(Without FF)
- or -
EGT
1560
FF
12.9
(With FF)
Captured peak EGT value
(plus peak FF, if FF equipped)
is displayed.
8
If you tap LF, the
difference from peak
EGT is shown. Tap
again to return to the
peaked EGT value.
EGT
-90 SET
(Without FF)
- or -
EGT
-90
FF
13.4
(With FF)
A useful mode for enrichening
the mixture to desired degrees
below peak. Just set to
desired value - no math
required! NOTE: Unit
remembers view last used.
9
Slowly enrich mixture
noting that EGT is
returns to peak then
drops. Stop enriching
at the desired EGT.
‘Peak’: best Econ.
‘ROP’ target: best
power.
EGT
1560 SET
(PEAK)
EGT
1460 SET
(100º RICH OF PEAK)