J.P. Instruments EDM 760 Pilots Guide - Manual (Page 30)

Display Symptom Probable Cause Recommended
Action
50%
Decrease in
EGT for one
cylinder at
low RPM Low
compression. Check
compression.
50%
Sudden off
scale rise for
any or all
cylinders
Pre-ignition,
or
Normalize view,
or failed probe
Full rich and
reduce power.
Change to
Percentage view.
Check probe
Loss of peak
EGT Poor ignition or
vapor in fuel
injection system. Have magneto
tested.
no sharp
peak
Decrease in
peak or flat
EGT
response to
leaning
process Detonation.
Usually the result
of 80 Octane fuel
in 100 Octane
engine. Enrich mixture,
reduce power and
relean mixture.
Repeat to find
power setting
where normal
peak is obtained
or run rich.
50%
Below
10,000 ft. full
throttle
causes
EGTs to rise Weak or
defective
mechanical fuel
pump. Apply booster
pump. If EGTs
drop, replace fuel
pump.
50%
CHT more
than 500°,
EGT normal.
Adjacent
EGT may be
low Leaking exhaust
gasket blowing
on CHT probe. Look for white
powder around
cylinder to
determine leak
area.
Alarms
The EDM-760 has programmable alarms. When a measurement falls
outside of its normal limit(s), the digital display will flash with the value
and abbreviation of the alarming item. If the condition triggering the alarm
returns to within normal limit(s), the display will stop flashing the alarm.
Page 26 Engine Data Management