The automotive coil would need to be grounded solidly to the firewall or better to the pony block.

Here are a couple of photo's of Eisemann coils I have here, one has been rewound by a Aussie maggie repairer, also in the photo is the patented Eddie Bedwell coil testing wire I mentioned previously, part number EB2016, I think it's time you quit spending time on that maggy and either send it off to be reconditioned or buy a reconditioned unit because the bearings in your maggy will almost certainly need regreasing for future use and a used magneto you buy will be in the same condition, needing regreasing, yes they might spark out of the shipping box but how well and for how long, the bearings on the armature will fail.

I've had 7 or 8 magneto's reconditioned since 2008 by 3 different Magneto "Experts" who charge $180 - $250 for their services, one guy I discovered simply used old parts from other magneto's and I had the coil in my "reconditioned" RC-2Q magneto fail immediately on my RD6 and I still have the blisters on my hands from trying to start that pilot motor for the first ever time for 3 or 4 hours!!! The 2nd guy was a new kid on the block who had bought a reputable magneto repair business from a older gentleman and my Eisemann G4 Edition 3 failed after just a few runs on the 2 Ton and it was obvious when Eddie Bedwell took that maggy apart that the new kid had cut corners and not done a full recondition job letting me down, and he wasn't cheap either, the 3rd guy I'm with now seems to be the best of the lot but none are perfect, bottom line is you want to be able to forget about your magneto once it is fitted to the tractor other than the occasional points clean.

If a pilot motor will not start you do not want to be second guessing if the magneto is the cause because it takes hours to get at the maggy on a D2 and D4 to file and set points and muck around, life is too short for that drama of hanging upside down in the cockpit every few months and from my experience a weak spark outside the motor when testing the spark plug will often result in no spark under compression, don't ask me why, but it is just is a sad fact of life with magneto's.
Mike

"Old wrote:

Yes, I would say so. Try probing the solder spot and the small tab that goes to the spark plugs. That is where you should get the 6,000 ohm approx. reading. If no reading the connection is either bad or the coil is open. A high reading could also indicate a poor connection. Take a reading and tell us what you get.

going from the solder to the front tab using the 20K setting on a cen tech digital multimeter I get 7.56. moving to 200k its 7.7 and at 2000 I get a 1 w/o any decimal pt,,, at 200 I get a 1 w/ a decimal pt about four places to the right.... testing from the wire that is there and the tab on front the readings are the same....

My mag was modified to use a automotive coil.

Removed all wires going to the points. Ran one wire from points to the coil. Added a condenser at the coil. Coil is mounted on the dash.

Drilled a hole in the cap where the stock coil would contact the cap. Bolted a plug wire to the cap, other end goes to the coil.

Battery grounded to the engine. Positive wire from battery to other side of coil, put a switch in this wire to turn it off.

It works properly.

"Mike wrote:

Here are a couple of photo's of Eisemann coils I have here, one has been rewound by a Aussie maggie repairer, also in the photo is the patented Eddie Bedwell coil testing wire I mentioned previously, part number EB2016, I think it's time you quit spending time on that maggy and either send it off to be reconditioned or buy a reconditioned unit because the bearings in your maggy will almost certainly need regreasing for future use and a used magneto you buy will be in the same condition, needing regreasing, yes they might spark out of the shipping box but how well and for how long, the bearings on the armature will fail.

I've had 7 or 8 magneto's reconditioned since 2008 by 3 different Magneto "Experts" who charge $180 - $250 for their services, one guy I discovered simply used old parts from other magneto's and I had the coil in my "reconditioned" RC-2Q magneto fail immediately on my RD6 and I still have the blisters on my hands from trying to start that pilot motor for the first ever time for 3 or 4 hours!!! The 2nd guy was a new kid on the block who had bought a reputable magneto repair business from a older gentleman and my Eisemann G4 Edition 3 failed after just a few runs on the 2 Ton and it was obvious when Eddie Bedwell took that maggy apart that the new kid had cut corners and not done a full recondition job letting me down, and he wasn't cheap either, the 3rd guy I'm with now seems to be the best of the lot but none are perfect, bottom line is you want to be able to forget about your magneto once it is fitted to the tractor other than the occasional points clean.

If a pilot motor will not start you do not want to be second guessing if the magneto is the cause because it takes hours to get at the maggy on a D2 and D4 to file and set points and muck around, life is too short for that drama of hanging upside down in the cockpit every few months and from my experience a weak spark outside the motor when testing the spark plug will often result in no spark under compression, don't ask me why, but it is just is a sad fact of life with magneto's.
Mike

I had a muffler armature go out once in the snow.... oh my.... I notice that both of your coils do not show the wire coming out of the bottom... ie the second wire.... were they there and broke off? I've found a solder joint on the bottom of mine that appears to the the old ground wire connection..... it reads out on the ohm....

"drujinin" wrote:

The automotive coil would need to be grounded solidly to the firewall or better to the pony block.

I wondered about that thinking what a nut I was for not at least trying it,.,,, the next move lol

"jmvmopar" wrote:

My mag was modified to use a automotive coil.

Removed all wires going to the points. Ran one wire from points to the coil. Added a condenser at the coil. Coil is mounted on the dash.

Drilled a hole in the cap where the stock coil would contact the cap. Bolted a plug wire to the cap, other end goes to the coil.

Battery grounded to the engine. Positive wire from battery to other side of coil, put a switch in this wire to turn it off.

It works properly.

Hello jmvmopar.... which side of the coil did you hook up the battery to ,,,

Case of the coil doesn't need to be grounded.



Coil should be marked + and - that's how I hooked it up. Just as shown in the wiring diagram above. Only other thing to remember is to use a coil that is for use without and external ballast resistor. Most coils are marked "internal" or "external" . External coils are only really supposed to use 9 volts or so to protect the points.

"mcbitchman" wrote:

I had a muffler armature go out once in the snow.... oh my.... I notice that both of your coils do not show the wire coming out of the bottom... ie the second wire.... were they there and broke off? I've found a solder joint on the bottom of mine that appears to the the old ground wire connection..... it reads out on the ohm....

No, there were never any wires from what I can see.

"mcbitchman" wrote:

going from the solder to the front tab using the 20K setting on a cen tech digital multimeter I get 7.56. moving to 200k its 7.7 and at 2000 I get a 1 w/o any decimal pt,,, at 200 I get a 1 w/ a decimal pt about four places to the right.... testing from the wire that is there and the tab on front the readings are the same....

7.5K ohms is still a good reading. Takes three connections to make the coil work. Primary wire is the one going to the points. Secondary wire/tab is the one going to the plugs. Third connection is a tab, wire, or mechanical connection to ground/housing/core.
Going from the secondary tab to the primary lead will not change the resistance reading as the primary side of the coil has very low resistance. Check the primary wire to ground/core or that solder spot. Should get a very low reading maybe 0.02 ohms or something like that.