Switchig a magneto to a distributor

Hey guys I have a 1944 John Deere model A. I had a nice chat with a couple of guys who had a similar tractor as mine. One the older guys asked me if I still had the "c", I said yes. I was told to switch the "c" mag out for the "x". So I started prices the renamed x mag and they are around $500. But I noticed that a remained distributor was only $275. Obviously I know I will have to mount a coil and wire in a switch but I would like to know if a distributor will mount directly up to the tractor or do I need a adaptor plate.

Pippen as far as I know (NO warranty its been too long lol) a Delco distributor mounts right there same as a Magneto.

Each, Mag or Dist, has advantages as well as disadvantages and to some "correct police" it MUST be same as it came from the factory or they kick you out of the show YEAH RIGHT LOL THEY CAN KISS MY GRITS

FWIW the later Wico X mag had improvements over the older C model

FWIW I prefer a Delco distributor over a Wico XB distributor

While battery polarity doesn't matter to a mag, your tractor was original POS ground, so if you keep it that way and wire up a battery powered coil - receives ignition switched voltage while + wires to distributor.

On a 12 volt tractor (if thats what you have??) you can use EITHER a 12 volt coil orrrrrrrrrrr a 6 volt coil with an external series voltage dropping (12 down to 6) ballast resistor. On a 6 volt use a 6 volt coil WELL DUH

John T

I echo John below.

If that A is original, it is a 6 volt system so a coil from Chevy pickup of the 60's should work very nicely with the Delco Distributor and your Deere dealer would have done exactly this had had you experienced this very problem back in the 1960's so would a Delco Distributor REALLY be that incorrect?

Our Deere dealer (Shearer Implement) did exactly what you're discussing to Dad's '51 B when he took it in to 'git it fixed". Dad thought it needed rings because when running the baler it absolutely drank oil & smoked badly! Turns out the bearings were so worn in the original XB distributor, the timing was all over the place. The rapid and constant speed changes typical of baling along with the vibration of our old IH baler was making sparks almost any time! Points could be made to break anywhere on the breaker cam depending on how the shaft was wobbling at the moment! Dad took it in expecting a ring job but it was back the next day with a Delco Distributor on it when he got home. Boy was he MAD until he got to the dealer who proved himself an honest and faithful dealer. He said if you're not happy with it we can ring it later & I'll not bill to haul it. It ran like a top, Shearer remained our dealer from then on, that B proved to be Dad's favorite tractor ever and it sits in my out building right now with those very same rings still in it!

PS.... If your A has been converted to 12 volts, I'd go with the same coil mentioned above PLUS an ignition resistor. Others may disagree but I've converted far more outfits to a "6 volt with resistor" (and bypass) design than I ever have to a no ballast coil! Been my experience the 6 volt & resistor seems to have fewer points issues PLUS, you can jumper around the resistor for an easier start on a bitter cold winter day too. That's what the 4 post solenoids were all about until electronic ignition came to the auto industry.

Hope that helps.

It's 12v positive ground, I know how to wire it up. Just wanted to make sure the distributor would mount up the tractor. In the future I will be putting electric ignition in it. I know people will say it's stupid or unnecessary, but I put an electronic ignition on my 54 JD 60 and it's amazing how easy and quicker it starts. Thanks for the info guys.

Looks like were pretty much on the same page Al. On a 12 volt tractor I also like a 6 volt coil with the external ballast and a ballast by pass while cranking as it can improve colddddddddddddd weather starts for darn sure.

For solenoid start tractors the old 4 terminal (In Out S and I) solenoids like you mentioned like Fords used have that small "I" terminal which is hot ONLY when cranking and can be used for the ballast by pass.

On the mechanical push down saddle mounted starter switches like many Deeres used, you can get them with the extra small side terminal that's again hot ONLY while cranking

Nice chattin with you Al, best wishes n God Bless

John T

If you should convert to 12volts and and buy a coil for a mid sixties Chevrolet then it needs a 1.8 Ohm resistor which is equivalent to the resistance wire on a mid-sixties Chevy. Or you could go to NAPA and buy a full 12 volt coil that doesn't need a resistor. This coil is about $40 at NAPA and over $100 at Deere

Good Morning Pippen, since Al and I first posted you have provided us with this new information:

"It's 12v positive ground, I know how to wire it up."

You haven't mentioned any alternator conversions and by keeping it ORIGINAL and POS Ground, there's no worry with swapping ammeter leads (assuming its already correct) and you say you know how to wire it, but for others, + of coil wires to distributor and - is fed via an ignition switch. As I'm sure you're already aware, but FYI for others, if it had a Mag it may or may not have had a dash "kill switch" installed which simply provides a ground to kill the mag "if so equipped" with a grounding kill stud like Wico X and a few other (C didn't typically have them) mags could be furnished.

A full 12 volt rated coil may be labeled "12 Volts" or "12 Volts NOT for use with Ballast Resistor" and will work fine unballasted on your 12 volt tractor. A full 12 Volt rated coil has a typical LV primary resistance of approximately 2.5 to 3.5 or so ohms DEPENDING ON make and model. Use of a full 12 Volt rated coil (NO ballast required) makes for easier wiring.

HOWEVER, should you so choose, there is an advantage to use of a 6 volt coil and an external ballast resistor (drops 12 battery volts down to 6 or so), in that you can by pass the ballast resistor while cranking to improve cold weather starting. On some Deere's (that used a ballast and by pass) the saddle mount mechanical starter switch has an extra small side terminal that's hot ONLY when the starter switch is engaged and that terminal can be wired up to the coil to by pass the ballast while cranking.

I have seen typical ballast resistors with an approximate resistance of 1.2 up to 1.8 or more ohms DEPENDING ON the LV primary resistance of the 6 volt coils they were designed to accompany. They basically serves as a 50 50 voltage divider in series with the coil so they drop 6 volts leaving 6 volts for a 6 volt rated coil. That's why their resistance is close to that of the 6 volt coil they were designed for so they drop approximately HALF of the battery voltage.

THANKS PIPPEN for the update and feedback, sorry to report what you likely already know, but it may help others

Best wishes and God Bless you and all here.

John T Longgggggg retired Electrical Engineer and rusty as an old nail so NO WARRANTY and if this isn't all correct hopefully some fine gents can correct the above, but I think its still true lol.

It's completely fine, this isn't my only 2 cyl Deere. I do know that I have to install a key switch or some kind a switch to be to cut off the power. I dont know when the x mag became standard but I believe that's when key switches were installed. I am not worried about keeping it totally original. I but this tractor to turn it into an antique puller. My goal is to keep it stock appearing. I am not worried someone telling that the distributor is not stock. I don't think it will "jack" HP that much if it all.

I don,t know ware you are pricing those parts but i have rebuldt XH mag ready to go fore $200.00 check you drive if it es long lug a dist will not work

I know feller who put a lot o lights on his 40! The generator couldn't keep up so he changed all the lamps to 12v & installed an alternator and a resistor on the coil. He deliberately changed the battery cables to skinny cables but had starting problems. It would crank well but started hard. It usually started just as you released the starter switch. That tells the story.

I suggested to him he bypass the resistor with a clip lead when cranking to see if that solved the problem He did & it jumped to life every time. Next was the suggestion to bypass the resistor with either a starter switch from something like a 70 D or a 60. They had a bypass mechanism built in!

He did that (though I'm not sure what switch he used) and the starting difficulties with the 40 went away!

(quoted from post at 17:21:50 07/21/17) I don,t know ware you are pricing those parts but i have rebuldt XH mag ready to go fore $200.00 check you drive if it es long lug a dist will not work

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I have looked on Steiners, and all-state ag( tractorpartsasasp.com) if I could find a remaned x mag for $200 bucks I would get due to it being cheaper then putting a distributor. To be honest I would rather have a distributor.

pipen i have both dist and mag to fit 200.00 ea plus shipping 13.45