Electronics always PREFER the Cold at least to temps well below what is seen in nature but can also TOLERATE temperatures well above natural temperatures also.
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This is what I believe the Flywheel story to be...
The Ignition Modules originally had no Soft start capability.
The trigger Cams on the flywheel are raised tabs that carry the magnetic field out to the trigger coils at the proper time.
As the Trigger Cams pass the Trigger coils, they produce two electrical pulses; a Positive one as the leading edge passes and a Negative One as the trailing edge passes.
The ignition modules use the leading Edge pulse for normal timing.
The trailing edge pulse was ignored and just occured at an unspecified time delay After the first one.
Later it was found that if the spark could be delayed during starting, it was much easier on the starter and the engine in general.
The solution was to use the trailing edge trigger pulse whenever the starter was energized and for 3-5 second afterwards.
This produced the Soft-Start and reverted to normal timing a few seconds later after the engine had achieved a normal running speed.
The original Trigger Cams produced the desired timing delay but it could be made even better if the Cams were widened so the trailing edge was delayed to 4° BTDC.
This resulted in the newer Flywheel with trigger cams with purposely dimensioned widths insted of the original arbitrarily dimensioned cams.
Both flywheels will produce a soft-start and run exactly as intended at power.
The difference is that the newer flywheel will produce a softer start than the original flywheel.
The Original Flywheel will produce a noticable soft start, just not as soft as the new flywheel.
And of course, Rotax specifies replacing the original flywheel with the newer, better flywheel.
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Roger, What say you?
