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Discussion Starter #1
Hi there everyone. I need some help getting this tractor to fire.

What I have:

12v bat +ground (new)
12v coil with external resistor (both new)
Generator with 12v regulator (existing, but I can read power back to the ignition)
Points distributor (new points,condenser,wires & plugs)

I have a typical “ran when I parked it situation”. I can read voltage on both sides of the coil and on both sides of the distributor terminal but there is no spark at the plugs when turning over I believe my issue is in points which I replaced.
I gapped the points at .025 on the impulse flywheel mark. Is there a 6v and 12v condenser if so could I have the wrong one or is it burned out? I’ve also read about the distributor housing needs to have a good ground. Not sure what to try next. PLEASE HELP. Thanks
 

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try a new condenser--cheapest thing to try. my family over the yrs has gotten bad condensers right out of the plastic packages.
 

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JDg, The first thing I'd do is verify the coil wiring. With a pos (+) ground system, does ignition switch wire go to + or - side of coil. Backwards will shorten both points and condenser life. Bob
 

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Discussion Starter #4 (Edited)
Condenser and wiring

I put a new condenser in the distributor that came with a kit. Plug, wires, cap, rotor and points. Are these parts specific to 6 or 12v?


Regarding the wiring it is as follows:

Solenoid to regulator
Regulator to ammeter
Ammeter to switch
Switch to in of external resistor
Out from resistor to - of coil
+ of coil to distributor

Hope this helps explain
 

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I like to use an old fashioned light bulb test light. If the points are closed it should not light on the distributor side of the coil. If it does follow the path to ground ( positive in your case ). One side of points to the other? Breaker plate and then the distributor housing. Then to the governor housing. Repair the open circuit.
When you crank the engine with the cap off you should be able to see the points spark when they open.
 

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Discussion Starter #6
I did try look for a spark with the cap off but did not see any. I’m wonderering if the condenser is bad or if the condenser wire is grounded out at the terminal. Is there a difference between a 6v condenser and 12v.
 

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I fought with my 24v M38a1 jeep for over a year on & off...Spark everywhere except the plugs.?

This was a unique system with waterproof plugs ,wires and cap. Real pita to troubleshoot.

The culprit was a Bad yet brand new rotor....was sparking from center pin of cap...through rotor to the top of distributer shaft.

Impossible to see......finally put the original rotor back in just for giggles and it started.


Off course it didn't help that the original army manual had a missprint of the firing order..yep , Pictures and all text were wrong. Finally found the revision/amendment but the $2 rotor was the problem.

I gotta get back to that project and finish the final features...30 cal Browning and all the proper mounting hardware:gizmo:
 

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Been there done that to many times!

I have had a bit of experience with point systems. First take off the cap and bump the engine over till you see the points close. Turn on the ignition and use a screw driver to push the points open and closed. You should be able to hear and see a spark in the gap each time you open them up. If you get a spark pull the coil wire out of the dist cap and see if when you break the gap it sparks to ground. If you have spark then your problem is flooded or bad plugs not sparking in the cylinders. 6 or 12VDC Condensers are the same. Even with a bad condenser you should get a weak spark breaking the gap on the points. Double check your gap a lot of times they close up some when you tighten the screw up. I always double check the gap. Look for Carbon Tracks on the Dist Cap inside and out that the spark can travel on to ground or another plug wire. I had one system give a bunch of people a problem to figure out once including me. Then I remembered something I have found before the coil wire damaged. The Carbon Core in the coil wire had burned out so far up the wire that it could not jump the gap any more. Just trimmed the wire back. Check that you have voltage to the coil when it is turning over. Some set up use a separate wire to feed the coil when turning over with a full 12 volts then when you let off the start it switches back to 9-10 volts to not over heat the coil. If the coil was required to be fed all the time with 12 volts you need a 12 volt rated coil. If not a regular coil will do that runs off 12 volts but requires the resistor to work very long. If your plugs are bad it won't start too. The point system is easy to see what is wrong compared to electronic systems!! You need to follow the power thru the circuit till you get to the plug and make sure there is not a problem. Sometimes you can install points in the dist and short out the stud going thru the side and that will stop the spark just like the points are always closed. You can make your coil spark with out a dist by putting +12 VDC to the positive side of the coil and just touch it off and on you will get a spark. If it sat and did not have spark I would think it had moisture under the Dist Cap most parts will not wear out sitting except electrical stuff getting corroded up. Worst thing to do is to start switching parts before you know the problem that is the big buck way of doing it. Like the guy who adjusts his Carb when it won't start but it ran the last time he tried? How did the Carb get out of adjustment sitting over night? Rotors can go bad but normaly it is carbon tracking on it to the shaft. All this stuff can be corrected to get you home in the old days. Now you pop the hood and there is a Foot Deep of hoses and wires controlling all the smog crap and pray the computer never dies!

Watch this U-Tube;https://www.youtube.com/watch?v=W94iksaQwUo
 

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It has been a long time since school days and learning about points. I had a G in 1980? Seems like capacitors could be tested with an ohm meter. You can remove it from the system and it should still fire, just not long term.
While some things get cloudy I do remember the best way to check for a shorted capacitor. Put the housing on a good engine ground. Connect the small wire to a spark plug wire and spin the engine over. Then put it on the desk with a note that says do not touch. Do not touch the housing and the terminal on the end of the wire in the process.
 

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12 V coils usually had a resister bypass while cranking. That is a bit longer topic but coils with internal resistors usually worked well and were easy to install.
 

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12 V coils usually had a resister bypass while cranking. That is a bit longer topic but coils with internal resistors usually worked well and were easy to install.
Your right and if the Bypass Circuit is not working it will not start but will have power when your not cranking it ignition on. It gives it a hotter spark and they figured when cranking the battery would drop in voltage so having a lower voltage coil they could hit it with 12 volts to start it better. That is why it is helpful to test it cranking to if it does not start. When I was 14 I got my first Car a Jeep it was not running till the next day! That is when my Mother said the Jeep was to learn on did not figure you would get tit going so quick! That when IU started learning more about engines 53 years ago but it started with old lawn mowers I would find, fix up and re/sell to make money as a kid. Most were Carb problems and got easier to fix. My Father died when I was 11 so I had to learn this stuff on my own no computers back then!
 

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Well.... as usual I had to educate myself about "why" positive ground.

Thats a couple hours I won't get back...led to a nice nap though.



I see you have a NEW coil.



One thing I did retain in this lesson was the Coils are wound different in a positive ground system......Is Yours?:munch:


Rumor has it that this is why the Model A fords were positive ground.......The huge shipment of coils from the supplier were wound backwards.......

Solution...swap the battery cables

Who Knew????
 

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Well.... as usual I had to educate myself about "why" positive ground.

Thats a couple hours I won't get back...led to a nice nap though.



I see you have a NEW coil.



One thing I did retain in this lesson was the Coils are wound different in a positive ground system......Is Yours?:munch:


Rumor has it that this is why the Model A fords were positive ground.......The huge shipment of coils from the supplier were wound backwards.......

Solution...swap the battery cables

Who Knew????
Changing the polarity of the Coil will change the direction the spark travels on the spark plug electrode gap. I always changed my real old rigs to Negative Ground not a big deal to do. Starters still turn the same direction either way.
 

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Changing the polarity of the Coil will change the direction the spark travels on the spark plug electrode gap. I always changed my real old rigs to Negative Ground not a big deal to do. Starters still turn the same direction either way.

The starter thing puzzles me...I read exactly as you say but It isn't sinking in to my brain...:banghead:

Generaters apparently you can "polarize" to run either way.....Ok how? I figure its simple.

The coil thing while I'll never completely understand..does make some sense and the theory is
once its running ....well spark is spark and its happening so fast it just dosen't matter.

"they" say..the adoption of negative ground was to decrease body/frame corrossion
and
In the same breath "they" say some marine applications are Still posative ground for the same reason.
Decrease Corrossion .

So in the end...are we getting bamboozled by the powers that be or is it like the way a rainbow works...?

It just does.......I like Joe Dirt:cheers:
 

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The starter thing puzzles me...I read exactly as you say but It isn't sinking in to my brain...:banghead:

Generaters apparently you can "polarize" to run either way.....Ok how? I figure its simple.

The coil thing while I'll never completely understand..does make some sense and the theory is
once its running ....well spark is spark and its happening so fast it just dosen't matter.

"they" say..the adoption of negative ground was to decrease body/frame corrossion
and
In the same breath "they" say some marine applications are Still posative ground for the same reason.
Decrease Corrossion .

So in the end...are we getting bamboozled by the powers that be or is it like the way a rainbow works...?

It just does.......I like Joe Dirt:cheers:

Most starters are a universal motor, meaning the magnets inside are actually electromagnets that are energized by the current from the battery. Reversing the input polarity will reverse the electromagnets as well as the armature, resulting in the motor spinning the same direction with either polarity applied.

Universal motors can be run on AC or DC, offer a high power to weight, a wide range of speed and are very rugged, which is why you'll find them on everything from vacuum cleaners to dremel tools to automotive starters.

You could open up the case and move some connections around to get where you want to go.

Any permanent magnet motor will spin the opposite direction with reverse polarity.
 

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Your right and if the Bypass Circuit is not working it will not start but will have power when your not cranking it ignition on. It gives it a hotter spark and they figured when cranking the battery would drop in voltage so having a lower voltage coil they could hit it with 12 volts to start it better. That is why it is helpful to test it cranking to if it does not start. When I was 14 I got my first Car a Jeep it was not running till the next day! That is when my Mother said the Jeep was to learn on did not figure you would get tit going so quick! That when IU started learning more about engines 53 years ago but it started with old lawn mowers I would find, fix up and re/sell to make money as a kid. Most were Carb problems and got easier to fix. My Father died when I was 11 so I had to learn this stuff on my own no computers back then!
My first car was a Savoy and I was 13. Wanna trade?
 

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Discussion Starter #18
Thanks for all the info. It looks like i have a few things to try this weekend.

One question is how do you bypass the external resistor during cranking? It has a foot pedal starter switch and I don't see how
a wire would attach to this. I'm assuming I'll need to get a coil with an internal resistor.
 

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Thanks for all the info. It looks like i have a few things to try this weekend.

One question is how do you bypass the external resistor during cranking? It has a foot pedal starter switch and I don't see how
a wire would attach to this. I'm assuming I'll need to get a coil with an internal resistor.
If you don't have a External Resistor then you need the coil with one built in.
 

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JDg, Not knowing anything about a "G" and a little about wiring in general, I've got mostly questions!

But first, if you plan on bypassing the existing ballast/external resistor, you DON'T WANT an internal resistance coil. Most coils operate at 7-9vdc. Your battery is 12 so it goes to an external resistor that drops the voltage to that 7-9vdc and it then goes to the coil windings. A coil with an internal resistor is supplied right from the battery with 12vdc. The internal resistor then drops the voltage to 7-9vdc and supplies it to the windings. With an internal resistor coil, no matter how it's wired, the coil windings get 7-9vdc.

Now, pedal operated starter switch: Is there an actual switch that the pedal operates? If so, I would think it has 2 terminals on it, one the the battery and one to the starter motor. If this in fact the case, a wire from the starter motor terminal (either on the switch or the starter motor) to the coil would supply 12vdc to the coil while the starter is turning. Once the pedal is released, the 12vdc stops and the normal ignition wiring through the existing external resistor takes over. If no physical switch, I've no idea! Bob
 
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