SERVICE BULLETIN #44

DATE:                    August 28, 1995

SUBJECT:              Rotax 912 Ignition Leads

APPLICABILITY:     All 912-Powered Kitfox's with Ignition Unit Mounted to the Engine

COMPLIANCE:       Mandatory

FROM:                   SkyStar Aircraft Engineering

After 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.

Prior 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.

After 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.

Replace 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.