19
b) Mode Switch
(recommended, on all boosted engines)
– Mode Switch
will be set to
VAR
for
most operations and is
required
for starting.
i) Running on one side only, turn Mode Switch from VAR to FIX for 2-3 seconds and then
back to VAR. The engine should run smooth in both positions. The firing position may
change with Mode Switch transitions, so a slight shift in rpm might be expected.
ii) Repeat with the other ignition.
Rough or significantly degraded behavior indicates a problem - not suitable for flight.
2) Cut-Out test should be done after initial installation, power plant maintenance, and at annual
inspection:
a)
The Cut-Out test checks ignition condition and the entire system (see Note 1) in challenging
conditions. Internal alternator output will vary with engine rpm. You are verifying the system
is capable of operation without aircraft power at speeds below your in-flight idle. Your
ground idle can go much lower than your flight-idle, so the Cut-Out test is a ground based
(only) exercise.
b) Operating on one ignition, lower engine speed to 1200 rpm. Then cut bus power to the
ignition. A slight rpm my dip may be expected with lower spark energy.
c) Very slowly lower the engine rpm until the engine reaches low idle limit or quits. A log-book
entry can help track Cut-Out trends over time.
d) Repeat Cut-Out test on the other ignition and then with both ignitions.
Note 1: The Cut-Out test marks the low-speed boundary of the entire system (not just the ignition)
when the ignition is self-powered. Spark energy is a significant, but not the only factor affecting cut-
out speeds. Mis-adjusted idle mixture fowled or partially fowled plugs, induction leaks, mis-adjusted
prop, and other factors can affect (elevate) cut-out speeds. Keep this in mind if ever investigating
the cause of elevated cut-out speeds. E-MAG bench tests every ignition to verify they self-power,
open air spark, down to 700 rpm prior to shipment. This is well below most in-flight idle speeds.
Note 2: When performing a Cut-Out test, if the engine falters allow it to come to a stop and fully
power down. Re-applying bus power or activating the other ignition at the last moment to keep the
engine running may not restore full operation and is unlike the power boundary event we are
probing.
Maintenance
Condition Inspection (annual)
1) Confirm Setup reference positions (TC, MIN, MAX) prior to removal. Look for discrepancies (if
any) from prior settings.
2) Check E-MAG web site for the most recent Manual (www.emagair.com/downloads), Service
Notes (www.emagair.com/service-notes), to verify equipment is current with all updates.
3) Ignitions come with a thermal sticker that will trip (turn from a light eggshell white color to gray or
gray/black) as case temperatures exceed 200 degrees (F). Dark gray or solid black indicates a
