I thought I would post my findings....but you can find the source material here:
http://www.jawamoped.com/JawaMoped_Elec ... nition.pdf
what I've learned is that these are basic ignition systems as long as everything is in place. If you have nothing to work with then you will have to learn what once belonged between the magneto and the spark plug....
and that will be an electronics history lesson..
There was originally something called a Tranzimo that timed and generated the high voltage spark. That must have been basic to wire because there are only two wires, current and impulse generator, going to the Tranzimo and one spark plug wire leaving it.
Other Jawas had a separate HT coil and a Thyristor which is some kind of inductive timing switch. It has 4 male pins...G, I, 1, 15
The alternating current comes from the top most coil on the magneto...it's usually a red wire. Behind the red wire is either a yellow wire or a white wire or a yellow AND a white wire. If it is only a white wire then that's called the impulse current line. The yellow wire is the impulse line also and the white wire behind the yellow wire is the ground...The impulse wire, regardless of color, goes to the
I pin on the Thyristor. Maybe the
I means Impulse.
But since the impulse current is timed to release the alternating current to the HT coil the current has to loop back around through the 1 pin. That is Ground. And that pin also is where the 1 terminal of the HT coil is jumped to. Then both the coil and the impulse current are both directed back to a ground that might be on the coil ring. I'm not sure on that because all kinds of variations exist. But I'm going to put it on the coil ring.
Then the 15 pin is the actual HT coil load and it goes to the 15 terminal on the HT coil where it is condensed to produce the spark on the plug.
thyristor pins:
G = alternating current line in/ red wire
I = Impulse generator circuit/ yellow or white wire
1 = Ground/ white wire AND 1 terminal from HT coil must be grounded on a coil ring screw
15 = load out/ HT coil/ whatever color you want.
The HT coil only has the #1 terminal that is jumped to the 1 pin on the thyristor and then back to the ground on the coil ring. I suppose these can take separate routes back to ground but the schematic shows them jumped together.
#15 terminal that comes from the 15 pin on the thyristor which is where the generated current is coming from at set intervals.
Also, the spark plug lead is a screw in type. I've read that the newer carbon fiber core spark plug wires are not recommended and my suspicion is that they don't mix well with the 1976 4 volt coil and 6 volt system of thyristors and a bicycle driven crank. It took some work for me to find a copper core spark plug wire but it came off an old Japanese HT coil...and I had to swap out the plug. But I trust it to work better on this moped.
That's my findings as of today and I'm hoping I can get spark when I put theory to practice.
I could be totally wrong but the schematics seem to suggest I'm in the ballpark.