change from battery CD system with dist to regular auto typ system

jerryjerry05

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,926
A while back someone posted a bunch of stuff on changing from a Prestolite/mag power to a points ignition system with a coil.
​It showed picks and part on how and what you'd need to change over.

​ANYBODY have a link to this post??

THANKS!!
 
Last edited:
P

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
I think your biggest problem is finding or converting the distributor to points. If the distributor already has points, then it's pretty easy.
 
N

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,434
Jerry the head of the thread is fallacious.
It is not changing from Prestolite to points.
What the youtube shows is how to convert to regular Automotive battery ignition system.

The thread should be "change from battery CD system with dist to regular auto typ system".

Motorola and Delta which were the manufactors of the ignition system are a battery CD system with and without points. Really easy to convert if you have a points distributor as pnwboat mention.

Prestolite is a CD system that charge the power pack from magnets which are in the flywheel and it did not have a distributor.
Much more to do and change such as flywheel, stator, trigger,coils and a lot to mod.
 
E

elliotlake

Seaman Apprentice
Joined
Jul 16, 2016
Messages
45
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?).
***
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.
***
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.
***
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.
 
E

elliotlake

Seaman Apprentice
Joined
Jul 16, 2016
Messages
45
PS. Have I said previously/
1976 Chrysler 140 4 cyl
Took off Magna____ ignition.
 
N

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,434
elliotlake the 75Hp is a Chrysler 3 cylinder 1977 which I still own.

Changing the preamp (trigger or electric eye) same thing only different names is not difficult.
It is in the dist and you have to remove the dist from the engine. Then pull off the pully and rotor/rotorshaft.
When doing this be careful not cracking the rotor. The rotor is pressed and maybe glued to the shaft.
If you crack it then you have to changed the whole rotor and shaft as a complete unit.

About the youtube by Mark Everett I have looked at it a couple of times but it was a long time ago.
If I do not remember wrong he checked if the preamp signal was able to trigger the MDS box by hooking it up and measuring the signal.
Do not remeber if it ended up with making an adapter (some electronic components) to convert to right level of the signal for the MDS.

If you have 12VDC at the blue wire at the dist. (ignition ON) and the cap with wire and spring loaded carbone pin is in good shape, then your preamp or CD box is bad if you do not have spark.

You should be able to check the preamp by measuring the signal at the white/black wire going from the dist. to the CD box.
The voltage should go from 12VDC to about 0VDC or vice versa when turning the pully at each slot at the rotor disc.

As I and pnwboat mention you have to find a points dist. if you are going to convert to regular auto typ battery system.
Your electronic dist will not fit for points.
 
jerryjerry05

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,926
Nordin that's exactly what I should have said.TY!!

​pnwboat and Nordin that's the response I was looking for.

Like I said I know very little about changing over the ignition systems.
 
You must log in or register to reply here.
Top