understanding the coil

eastonct124 · #1 01-02-2011, 11:01 PM

OK guys, it's my time to complain.

i checked the beast and realized (after posting something I was not totally sure of) "The Beast" ...my 124, wasn't wired correctly.
Tonight, I switched the wires to the coil per manual.
Harness to pos+, points and condenser to neg -.
I can get it to fire when holding my hand over the carb....runs for a few, then shuts off.
Tried starting at normal start (I do 1.25 out for both screws) and it just wont start with or without choke. I kept adjusting the carb settings out more and more and tried everything.
it would only fire when the throttle was closed.
It would start, run alittle, then die. Puffing dark smoke the whole time.
So, i put it in the old computer... blacksmoke= too much fuel.
Very strange considering all I did was change the polarity of the coil. (I think that is the proper terminology).
I'm not looking for comments, just some clarity on the function/workings of why the coil worked for three years wired wrong, and wired correctly needs a full reset on everything.

_DX3_ · #2 01-02-2011, 11:16 PM

Have you verified all of your wiring is correct? If it ran good that long wired incorrectly that would make me think something else is amiss. Have you tried wiring it back to the way it was and seeing if it will still start and run as good as it did before? If not then something might be causing the carb to be rich. Such as a stuck float, some dirt, etc.

mmzullo · #3 01-03-2011, 08:41 AM

Replace the points and condensor. I got a 73 once that the PO had switched the + & - side of coil and it wouldn't run. Switched the wiring around and it ran but poorly. Put in new points and condensor and ran perfect. If you have a set set try it. Points could of had burnt up from too much voltage.

ol'George · #4 01-03-2011, 09:28 AM

Quote:

Originally Posted by eastonct124

OK guys, it's my time to complain.

i checked the beast and realized (after posting something I was not totally sure of) "The Beast" ...my 124, wasn't wired correctly.
Tonight, I switched the wires to the coil per manual.
Harness to pos+, points and condenser to neg -.
I can get it to fire when holding my hand over the carb....runs for a few, then shuts off.
Tried starting at normal start (I do 1.25 out for both screws) and it just wont start with or without choke. I kept adjusting the carb settings out more and more and tried everything.
it would only fire when the throttle was closed.
It would start, run alittle, then die. Puffing dark smoke the whole time.
So, i put it in the old computer... blacksmoke= too much fuel.
Very strange considering all I did was change the polarity of the coil. (I think that is the proper terminology).
I'm not looking for comments, just some clarity on the function/workings of why the coil worked for three years wired wrong, and wired correctly needs a full reset on everything.

FWIW:
Proper coil polarity is still to this day, a debated subject.
It is generally accepted to ground through the trigger system (points or electronic) the negative side.
And apply the power to the + side from the ignition/power source.

BUTT,
For many many years, there were manufactures that believed just the opposite.
As well as those that believed (mostly in the 6 volt days) that it was better to have a positive ground battery system.
General Motors believed in a negative ground system, Ford and Chrysler positive ground, as well as John Deer and I.H. among others.
I remember the pre war Chevrolet's (41-42) used a "polarity reversing switch" in the ignition system circuit.
The switch changed the coil polarity every time the ignition switch was turned off/on.
It was G.M's belief that it gave much more point life as the material buildup was minimized.

Ignition points, as they operate, build up a minute amount of material from one point to another as they ark.
It is similar to a ark welder principal,
one side has a mountain and the other side has a valley, so to speak.
if one looks @ a set of well used points, it is quite obvious.
The build up will be all on one contact, say the stationary contact, if the polarity is changed the build up will be on the moveable contact.
All this goes to show a coil will operate just as efficient with either polarity.
If you change the polarity like you did, I would file/clean the points or replace them/reset the gap.

In 1955 most all in the auto industry went to 12 volt systems and universally to negative ground as transistors were just beginning to be put in the power supply of radios,
and the coil polarity followed suit.
The build up of material on the points makes it difficult to set points correctly with a feeler gauge, that is why using an ohm meter or point setting meter, is a more precise way to set points and effectively, timing.

eastonct124 · #5 01-03-2011, 10:15 PM

I'm an idiot...at times.

It was wired correctly.
When I ran out to the garage to check to make sure I was telling someone the correct way to wire the coil....I just looked quick, and for some reason unknown to me, I thought it was wired backwards.
I can't retain the proper sides of the coil, so I always have to check on a running machine.
Sorry if I caused any undue stress.