August 28, 1995
Rotax 912 Ignition Leads
All 912-Powered Kitfox's with Ignition Unit Mounted to the
SkyStar Aircraft Engineering
flying thousands of hours with Rotax 912 engines on several of our
factory-built aircraft, we have experienced occasional malfunctions of
the ignition system of the engine. We have found that the vibration of
the engine can tend to break the wires which run from the electronic
module (Rotax P/N 965-356) and the rubber isolator mounts. The wires
typically break if they are not properly anchored to reduce vibration.
If one of these wires should break during operation, the engine will
either run on one ignition
circuit only or one of the ignition circuits will not be able to be
disengaged at shutdown. This will occur because two of these wires
provide the charge current from the stator at the rear of the engine
to the coils, and the other two wires are the equivalent of the 'P'
leads on standard magneto ignition systems.
to continued operation of your aircraft, inspect these wires to
determine if any of the wires are broken. Although the wires may look
acceptable, the leads may actually be broken inside the insulation.
You may be able to determine this by carefully feeling the wires along
their length. If you do
find that any of the wires are broken, cut out the broken segment and
splice in a new piece of stranded wire of the same gage using
crimp-type butt splices.
you have verified the condition of the wires you must secure them to
reduce the amount of vibration imposed upon them. This may be done by
attaching the wire harness to the electronic module
mounts with either cable ties or a metal clamp. Be certain that
whatever means you use to capture the wires, however, will not wear on
the insulation. However you choose to anchor the harness, you should
attempt to keep the freedom of movement which the harness can experience
to a minimum.
any rubber isolators if you should notice any wear on them. If the
isolator which needs replaced is the small one, call our Customer
Service Department and order a replacement, (P/N 47000.000 - current
cost is $4.50). If there is wear on any of the three larger isolators,
call your local Rotax dealer to order replacements.