John deere A help

[Johnau07]

I'm still working on my john deere A with a distributor on it. The thing is running so good but I was doing some looking up the other day for the wiring. What I am wondering is the wire that comes from the distributor to the coil, where does it go, on the positive or negative terminal. Would that have something to do with it running on 1 cylinder at times?

 

[J Hamilton]

Is it 6 volt or 12 volt? Pos or neg ground? If pos ground the neg terminal of the coil goes to the dist. If neg ground the pos terminal goes to the dist.

 

[Rodney51Cub]

John Deere A's were positive ground so the wire from coil to the distributor goes on the positive post of the coil.

This post was edited by Rodney51Cub on 08/01/2023 at 07:17 pm.

 

[matthies]

Nothing to do with running on one cylinder. Either plug or wire, neg ground on battery, neg on coil to dist, pos ground battery, + to coil. Generator were + ground, alternators - ground.

 

[willie in mn]

OOOPS! Got that backwards. Any polarity sensitive device matches the polarity of the battery.
If pos ground, pos term of coil goes to ground through the points in dist, & neg term of coil goes through ign switch to neg term of battery.

Willie

 

[J Hamilton]

You are right, my mistake! I got myself mixed up with typing all the pos and neg stuff.

 

[rustred]

i agree.lots of times they will not even run when the coil wires are backwards, due to the spark being too weak.

 

[John T]

Good morning John, your good questions:

What I am wondering is the wire that comes from the distributor to the coil, where does it go, on the positive or negative terminal. Would that have something to do with it running on 1 cylinder at times?


I agree with the other good gents. If ???????? its still as original POS ground the coils POS goes to distributor.

Its best and the ignition system is more efficient if the coil polarity is correct, but it will still run if not

Running on only one cylinder at times (if so??) can be caused by different things of which a reversed coil IS NOT the most common cause.

Hope this helps

John T

 

[teddy52food]

How is that? With a magneto half are positive & half are negetive ground.

 

[John T]

With a magneto half are positive & half are negetive ground

DITTO X2 Teddy, FWIW I agree. As you know, a TYPICAL magnetos rotating Magnet has a North and a South MAGNETIC polarity which results in an induced POS or NEG ELECRIC polarity potential in the armature in which it rotates, thereby eventually resulting an opposite polarity sparks. I think thats right but its been a while lol

John T

 

[Meangreen]

My dad's A runs on one cylinder sometimes, but that's because the head gasket has a tiny leak and the plug one one side likes to foul out. The other thing is if it is the same side that quits working, maybe you have a bad spark plug wire. Otherwise I think everyone else's advice will lead you in the right direction.

 

[Johnau07]

It is a 12 volt system and the positive goes to the starter and then up to the amp gauge to where it goes to the key switch and to the coil. The gauge is hooked up right but the wire coming to the coil from the gauge is positive and the wire going to the distributor from the coil is negative.

 

[Johnau07]

The wire that comes from the distributor to the coil is on the negative side right now. And the positive side goes to the gauges

 

[Johnau07]

Another thing I'm wondering is that I put new points and roter on the distributor but not a cap, so it may be to worn down on one side.

 

[teddy52food]

John; Nice to agree on something! Take care. Don. Now another ?? If you have a large coil big enough to put a rotating magnet rotor in it, Would the current go the same way in the coil if you have the north pole going up and the south pole going down?????

 

[Johnau07]

I have done some switching around on the wires to how she should be and it sounds exactly the same. I also have done some more research and found out the at idle, it runs more on the Lh side, but under a load, it sounds perfect. That is what is happening and that is just on my part. I will still switch the cap though.

 

[rustred]

Leave the coil wires as they are to be according to your batt. Ground. It would have been of more benefit to switch plugs and try that. Then the wire , then worry about a cap and rotor as they are to be changed together, plus look at the contacts, are they worn? How old is it ? Dont need to change stuff just to say its new. Have u checked the points and made sure the gap is correct??? Did u check the timing? Last is a carb adjustment. Have u pulled the wire off the good firing side to see what the other side is doing? There u go stuff to try and report back.

 

[rustred]

Ok so thats correct because u said u have neg ground 12 volts.

 

[Johnau07]

Everything has been gone through, a brand new carb, plugs wires, and the timing and gap is correct. The cap for the distributor in original which is from 1949, one side is a little worn down. Everything else is fine but it does run good after doing some more research on it.