2mm axial play on shaft of Ducati ignition...

[Roland]

...doesn't seem right.

I know, i have to take it apart.
But what is the problem here, missing spacers, or is it normal?

[Duccout]

Normal!


Colin.

[Roland]

Thanks!

[Roland]

I am very interested in the mechanics behind this assembly.
Especially why it is normal and why it is working this way.

Cross section of it would be very nice, something like this one attached.

Found this drawing somewhere but cannot remember.
It is very nice, perhaps new stuff based on 3D model.
Is more of 2D / 3D stuff available?

Roland

[Roland]

Another question on this ignition, please:

Where is the advance generated?
Transducer, pickup, or some centrifugal force device behind it?

Could not find an answer in drawings and manuals...

Thanks again

[graeme]

My understanding is that the faster the rotor spins past the coil the more it advances the spark up to the required 28 degrees (for 450)

Graeme

[Jordan]

CDI ignition advance changes according to engine speed.
The trigger coil generates higher output when going faster, making the ignition point sooner.
The output is AC sine type waveform with a pulse once per revolution.

Advance behaviour can be changed by number turns of trigger coil wire, strength of magnet, distance between magnet and coil.
Lots of things you can play with.

[Roland]

Thanks!

[Jordan]

Sometimes a mechanical advance mechanism is used with CDI, such as on Honda CT110.
I don't know why they do that, but the trigger device can be arranged to provide a nearly static ignition at all speeds, and the advance action is done mechanically.