BOMBARDIER 1996 Ski-doo MX Z440 Handbook page 196

Starting with most 1990 Ski-Doo models, a Nippondenso CDI system with only one generating coil
was introduced. This system is identified by having only two wires running from the stator plate to
the CD box. The two generating coil system has three wires. This system functions the same as the
dual generating coil system but has the following differences :
1. The timing retards more at high RPM's. (See graph.)
2. The voltage drops at high RPM's. (See graph.) Up to 7500 RPM, it produces higher voltage.
3. The resistance value of the generating coil is different. (See Shop Manual.)
4. The CD box and high tension coil are also different and have different testing and
resistance values. (See Shop Manual.)
There is also a racing version of the two generating coil Nippondenso CDI. It is used on the twin
track oval racers. The function is similar to the other Nippondenso CDI but has an additional red
wire from the generating coils to the CD box. The CD box circuitry is different and uses this signal
from the generating coils to significantly retard the ignition timing at high RPM's. (See graph.)
The main advantage of this system is to allow a lot of ignition advance at low RPM (which
significantly increases low RPM H. P.) but retards at high RPM to prevent the engine from going
into detonation. This helps regain "lost" low RPM H.P. on engines that have been modified for
maximum H.P. at high RPM.
354 twin track complete magneto assembly
CD box only
Ignition coil only
Use of the racing ignition system requires a new keyway position on the MAG end of the
crankshaft. All three of these systems are referred to a 4 pole systems.
Ignition timing is adjusted on these ignitions by rotating the stator plate. To advance the timing,
rotate the stator opposite to the direction of crankshaft rotation. Always use blue Ioctite an the
Starting with most 1993 Ski-doo models, a different version of Nippondenso CDI system is being
used. This system has 12 magnets on the flywheel and 12 poles or ends on the stator plate. This is
referred to as a 6 pole system. Power for spark ignition is produced by generating coils and power
for the lighting system is produced by the lighting coils.
Ignition timing is controlled by the position of a trigger coil which is mounted on the outside of the
flywheel. A trigger coil is a small pick-up coil that sends a signal to the CD box when a protrusion
on the flywheel passes by the trigger coil. Moving the trigger coil opposite to the direction of
crankshaft rotation will advance the ignition timing. This ignition system has quite a bit of advance
built into the timing curve. See the accompanying graph to see the exact curve. All engines using
this ignition have the same timing curve but the initial setting will vary depending on engine type.
The 779 three cylinder uses a slightly different version of this ignition. The generating coils are
wired to produce a high speed and a low speed generating coil circuit. The timing curve is the
same as the two cylinder version. See the graph to view the actual timing curve.
04-94
PART NUMBER
486014300
486014400
486014500