Nordin, Sorry but I do not know how to reply to the thread which brought me here

I will try and not get you guys lost in matrix.
BUT first, you wrote:
"I had an issue with a 75Hp with breakerless dist. First the CD module (power pack) was bad. Changed the pack, got spark BUT fried irregularly."
"Changed the preamp and then it run as it should"
Was this hard to do?
Mind you I have an OLD 1976 Chrysler...It looks like 99.9pct it is the light signal (is that the preamp?).
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I was trying to figure out how the light triggers the coil; from what you said I follow. There is a constant 12v going into the timing light unit and a wire from my CD ignition (presume a signal to CD.
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I have a brand new MSD CD which Mark Everett YT and some others have used.
I also have a new coil.
I made up a new wire set. All the wires have continuity.
A marine mech just said the cap looks ok.
When I turn over the engine no spark yet on any cylinder.
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I should have started at the dist end first, being a novice I made a bad diagnosis.
Perhaps this is good --- I am far enough in and invested that I want to find a reasonable solution if it exists.
My preference is to stick with the optical and only go points if that is possible. This system may not have pickups under the flywheel (beyond me for the moment.