Section12ELECTRICALSYSTEM
Subsection 01 (IGNITION SYSTEM)
Secondary Winding
The spark plug caps must be removed from high
tension cables, because they are resistor caps.
The cap resistance is 4.48 k
.
A00E0QA
1
2
1. Resistor cap
2. High-tension cable
Using a multimeter, check the resistance between
the two high tension leads with the spark plug
caps removed.
Theresistanceshouldbe12±3k
at 20°C.
NOTE: A short circuit will read 0 ohm (or close to)
on ohmmeter.
787 RFI Engines
Primary Winding
F07H0EA
1
3
2
IGNITION COIL
1. Primary side
2. Secondary side
3. Ground wire
Disconnect the wire connector on the primary side
of the ignition coil.
Using a multimeter, check the resistance between
the terminals 1 and 2. Repeat a resistance test
between terminals 2 and 3.
The resistance should be 0.3 to 0.6
at 20°C.
If not within specification, replace the ignition coil.
If the ignition coil test good, check the power sup-
ply on the primary side.
Disconnect the ignition coil 3-pin connector.
Check to see if there is approximately 6 Vdc
between the red wire and engine ground.
If there is no voltage, either the MPEM or the
wiring harness is defective.
Secondary Winding
Due to the integrated diode, it is not possible
to take any resistance measurement of the sec-
ondary winding on the 787 RFI models.
DYNAMIC TEST
All Models
Use an ignition coil tester, available from
after-market tool/equipment suppliers.
CAUTION: Do NOT use coil tester on metal
work bench. Follow manufacturer instruc-
tions.
– With ignition coil removed from craft, discon-
nect spark plug caps from high tension cables.
– Hook high tension leads from tester to ignition
coil high tension cables.
– Connect2smallertesterleadstoprimaryof
ignition coil.
F00H14A
1
2
TYPICAL
1. Leads to secondary
2. Leads to primary
– Turnpowerswitchto12voltsandyoushould
observe spark jumping at a predetermined gap
of7to8mm(.276to.311in).
If there is no spark, if it is weak or intermittent, the
coil is defective and should be replaced.
554 smr2004-Complete Line Up
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