Technical data

Section 08 ELECTRICAL SYSTEM
Sub-Section 02 (IGNITION SYSTEM)
08-02-3
Holder Relay
The holder relay is used to prevent discharge of
the battery, through the ignition system, when
the craft is not running. The relay is in the conven-
tional electrical box.
Ignition Coil
The ignition coil steps up the voltage input from
the DC-CDI module and the end result is firing of
the spark plugs. Output of this coil has been in-
creased by 3KV. The coil is housed in the rear
electrical box.
All Engines
Engine Rev Limiter
It has 3 functions :
– Keeps high voltage away from safety lanyard
switch.
– Provides engine stop by grounding the primary
coil.
– Limits engine RPM to prevent over-revving.
– A defective rev limiter may cause the following
problems :
– No spark.
– Uninterruption of spark when engine start /
stop and safety lanyard switch is used.
– Incorrectly controlled engine maximum RPM.
– Misfiring / black fouled spark plugs.
To check engine rev limiter, connect an induction
tachometer (P / N 295 000 100), start engine and
check its maximum speed ; it should be around
6550 ± 50 RPM for a 587 engine, 7000 ± 50 RPM
for a 717 engine, and 7200 ± 50 RPM for a 787
engine.
IGNITION TIMING PROCEDURE
Before checking ignition timing with a strobo-
scopic timing light (dynamic test), it is mandatory
to scribe a timing mark on the PTO flywheel (stat-
ic test) corresponding to the specific engine.
Also, the timing mark scribed on the PTO flywheel
can be used to troubleshoot a missing or broken
magneto woodruff key.
NOTE : Do not use the factory mark found
on the PTO flywheel to check ignition timing
or troubleshoot any problems.
CAUTION : The relation between the PTO
flywheel mark position and crankshaft po-
sition may change as the PTO flywheel is
screwed on the crankshaft. As an example,
when the PTO flywheel is reinstall on the
crankshaft, it can slightly turns on the crank-
shaft when the engine is accelerated, even if it
is properly torqued. This is enough to obtain a
false ignition timing reading. Always verify
PTO flywheel mark position (static test) before
checking ignition timing with an appropriate
timing light (dynamic test).
787 Engine
Normally ignition timing adjustment should not be
required. It has been set at factory and it should
remain correctly adjusted since every part is fixed
and not adjustable. The only time the ignition tim-
ing might have to be changed would be when re-
placing the crankshaft, the magneto flywheel, the
trigger coil, the DC-CDI module or the MPEM. If
the ignition timing is found incorrect, you should
first check for proper crankshaft alignment. This
might be the indication of a twisted crankshaft.
With this new CDI system, the ignition timing can
be checked with either the engine hot or cold. Al-
so, the ignition timing is to be checked at 3500
RPM with the timing light.
Between 3000 and 4000 RPM, the spark advance
does not change. So when checking timing at
3500 RPM, a change in engine speed within ± 500
RPM will not affect the timing mark when
checked with the timing light.
WIRE FUNCTION
WH/GY Communication for DESS lanyard
TA
Power to the monitoring beeper and
sensor
PU Power
BK/YL Safety lanyard switch (DESS)
YL/RE Start/stop witch (handlebar)
WH/BL Data transfer (low voltage)
GY/WH RPM data to MPEM
BK Ground between CDI and MPEM
BK External ground
BK Ground for safety lanyard
YL/RE Starter relay
RE/PU
Power to instrument
(oil/fuel/etc.)
RE/BL Power to holder relay
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