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Posted By: Ola Capacitor timing - 10/29/20 10:22 pm
Can anyone explain why capacitor- and battery ignition should be timed different?

[Linked Image from oseose.webs.com]

Regards
Posted By: Allan G Re: Capacitor timing - 10/29/20 10:43 pm
Originally Posted by Ola
Can anyone explain why capacitor- and battery ignition should be timed different?

[Linked Image from oseose.webs.com]

Regards

Energy transfer and capacitor ignition is different. Your diagram is of an energy transfer system. Easily recognised by the 5 wire stator which feeds the coils directly. Timing I believe is suited to the magnetic flux (and I’m going out of my depth)...

But capacitor and battery ignition are timed the same.
Posted By: gavin eisler Re: Capacitor timing - 10/29/20 11:47 pm
The answer is here in detail
https://www.britbike.com/forums/ubbt...pairing-an-et-ignition-system#Post633297

In short

ET ignition is an exploded magneto, Allan has it right, its to do with the magnetic flux peak, also the reason for the ltd advance retard range, stock AR goes out of the juicy spot. ET has a special AR and points cam.
Posted By: quinten Re: Capacitor timing - 10/30/20 8:48 am
the ET ignition is not dwelled . ( nor is a magneto )
the charge is held in the stator by the shunted/closed points .
the stators magnetic charge is only released as the points open ,
this flashes the primary winding of the coil ... which kicks the secondary and spark .
it all must happen ... timed to be near the peak of a AC wave .
the peak voltage is used as it is made .

the dc ignition is dwelled/charged like an electromagnet ... wth the points closed
( and hooked to a dc power source )
when the points open , input power is lost , the coils primary field collapses ,
... kicking the coil-secondary and the spark

the AC points cam does not dwell with AC application .
Posted By: Ola Re: Capacitor timing - 10/30/20 11:38 am
Thank you, gentlemen.
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