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Super C no spark - changed everything twice still no spark

M

mkirsch

Well-known Member
This Super C quit on me, like I shut off the switch. No spark.

I've dealt with 100 no-spark problems, but this one has me baffled. We've gone through everything TWICE, still no spark.

1. 12V directly to the coil = no spark at the coil.
2. Known good coil and coil wire = no spark at the coil.
3. 12V directly to known good coil = no spark at the coil.
4. New points and condenser = no spark at the coil.
5. Another known good coil and coil wire = no spark at the coil.
6. 12V directly to the second known good coil and wire = no spark at the coil.
7. ANOTHER new set of points and another new condenser = no spark at the coil.

The rotor *IS* turning.

There is 12V to the coil.

Points are gapped at .020.

I've never seen one like this before. There's nothing else to look at or change. It just won't spark.
 
(quoted from post at 18:05:24 06/01/14) This Super C quit on me, like I shut off the switch. No spark.

I've dealt with 100 no-spark problems, but this one has me baffled. We've gone through everything TWICE, still no spark.

1. 12V directly to the coil = no spark at the coil.
2. Known good coil and coil wire = no spark at the coil.
3. 12V directly to known good coil = no spark at the coil.
4. New points and condenser = no spark at the coil.
5. Another known good coil and coil wire = no spark at the coil.
6. 12V directly to the second known good coil and wire = no spark at the coil.
7. ANOTHER new set of points and another new condenser = no spark at the coil.

No expert here and do not know if it matters , but how is your ground from the battery to the tractor.

The rotor *IS* turning.

There is 12V to the coil.

Points are gapped at .020.

I've never seen one like this before. There's nothing else to look at or change. It just won't spark.
Click to expand...
 
Have you tried a test light connected to wire between coil and distributor?

With power to coil and engine cranking the light should be on with points open, off with points closed.

Always on means points not making closed contact or open connection

Always off means points not opening or shorted connection
 
One thing I would look at is the ground cable and its connections, have had cables be corroded apart internally, but look like new outside as well. Also, are the bracket for the coil and where it mounts CLEAN?
 
Put a piece of plastic between the points. use a test light and with it grounded, and 12v to the ign sw side of the coil, test the distributor side of the coil. Light lights -- test the distributor terminal on the side of the dist. Light lights -- test the movable point -- light lights points are dirty or not grounded. Test ground of distributor as well.
If the light fails to light at any point above, the component between that point and the 12v source has failed. Jim
 
I had a similar problem a while back. It was either the strands in the feed wire were 99% broken or hidden corrosion in a connector or where connector bolted on. Showed 12 volts potential but would not flow any current.
 
If you work through my Ignition Troubleshooting Procedure linked below, it may well help you find the cause. Especialy try the test lamp on the coils output (to distributor) terminal and crank her over and the light should flash ON (points open) and OFF (points closed)......

Give it a try and let me know

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=5745

John T
John Ts Ignition Troubleshooting
 
With your points open & your ignition switch on you should have voltage on both small terminals on your coil. Make sure where your condenser wire
is connected isn't touching metal. Hal
 
I've tried bypassing both wires to the coil with new. There's 12V on both sides at the proper time. Still no spark.

Everything's new or replaced with known good components. No spark.

The coil body isn't grounded, right?
 
I had something similar happen to me recently. The band spring on the points broke so I thought I"d replace the condenser while I was at it. Put everything back together and no spark. I got looking closer and found out that when I replaced the condenser I had grounded the terminal to the distributor body. Relieved the ground and the SC fired right up.
 
"There's 12V on both sides at the proper time."

YES 12 volts on both sides "at the "proper time" which is ONLY when points are open. When they are CLOSED there should be ZERO volts with respect to frame ground on the coils output (to distributor)

"The coil body isn't grounded, right?"

The coils outer metallic core/frame doesn't matter if its frame grounded or not.

So, when you ran through my Troubleshooting Procedure I linked for you below, did the test lamp go ON when points are OPEN but OFF when they are CLOSED?????????

If you use a plug wire out the coils top HV tower, thereby by passing the cap and rotor, and use a spark plug with its threads frame grounded or place the other end of the wire to within 1/4 inch or so off frame ground and turn her on, each time the points have been closed but then they open IT SHOULD SPARK, does it????????

Run my Troubleshooting Procedure and let us know what happens, that's about all we can do for you from here.

John T
John Ts Ignition Troubleshooting
 
Check your wiring from the coil TO the distributor. Is there a wire that's grounding out because of a bare spot? Or maybe the conductor in the wire itself is bad [hey, it happens]. Run a jumper wire from the coil to the points side of the distributor...if that changes anything, replace the wire.
 
I have a 230 that just died one day. Turned out the new switch I bought was bad. Put the old switch back on and it started right up.
 
Yes, John T, I ran your troubleshooting procedure. Twice.

Points open = light on, 12V
Points closed = light off, 0V

I have been checking for spark straight from the coil the whole time. Bypassing the cap and rotor as you recommend.

We had the cap, rotor, and inner cover off. The points are opening and closing as the engine is cranked. There is no spark.

I ran a brand new wire straight from the battery + to the coil. Bypassing the switch. There is no spark.

I ran a brand new wire from the coil to the distributor. There is no spark.

The post on the distributor doesn't seem loose or damaged in any way. It has all the right parts on the inside, and nothing is touching the distributor body.
 
Disconnect the coil to distributor wire at the through post on the dist. Connect that terminal end on the wire to a good condenser wire, and ground the condenser body. With 12v to the ign side of the coil, touch the lead and condenser wire to ground, it should spark a little, as it is acting as points. When you break this connection to ground, the coil should spark. If it does not it is a bad coil. This process eliminates the distributor all together. Jim
 
YIKES MK you done tried everything and still no spark grrrrrrrrrrrrrr lol

I think Id just use some small jumper wires and run a hot wire to the coils input (NOT to distributor) and have another small jumper wire on the coils output. Still have a plug/coil wire out the coils top HV tower to a plug or just within 1/4 inch from frame. Take the coils small output (normally to distributor) jumper wire and touch it to frame and then remove it EACH TIME ITS ON THEN REMOVED THE COIL WIRE (or plug) SHOULD FIRE TO FRAME.

This completely by passes any condenser or points problems or cap and rotor problem, so if the coil conducts current and then its interrupted it should fire unless its a bad coil!!!!!

John T
 
SEEMS EVERYONE HAS HAD A SHOT. NOW MY TURN. PLEASE DISCONNECT THE HOT BATTERY CABLE FROM BATTERY. TAKE A LEAD WIRE AND CONNECT DIRECTLY TO BATTERY POST WITH NOTHING ELSE ATTACHED EXCEPT GROUND WIRE TO THE BATTERY AND TRACTOR. TAKE THE JUMPER FROM THE HOT POST TO PLUS SIDE OF COIL. CHECK ON NEG SIDE TO SEE IF YOU HAVE CURRENT. IF SO,HOOK UP DIST WIRE, AND SEE IF FIRE TO POINT. IF SO,SHORT IS IN BATTERY CABLE,SWITCH, OR HARNESS OR POSSIBLY STARTER. I HAVE HAD A STARTER SHORT OUT AND DO THIS BEFORE. BY WIRING DIRECTLY FROM POST, YOU ARE ELIMINATING EVERYTTHING BUT COIL,AND DIST. ALSO, THERE COULD BE A BAD CELL IN BATTERY DOING THIS OR ALTNATOR SHORTED.
 
Ok, I was wondering if I could just touch the - lead from the coil to the frame, remove it, and generate a spark.

I tried that. No spark!!!!

With MULTIPLE known good coils!!!

As you said John, GRRRRRRRRRRRRRR!

The battery is 12V, and cranks the living snot out of the tractor. It's a 6V coil and the ballast resistor has been bypassed for testing. This thing should knock me on my a$$!

I won't be back at it again until Sunday. Maybe Dad will figure it out by then. We can get it running long enough to drive it off the edge of the gulley...
 
Yep I hadn't read yours until after I posted mine, great minds think alike maybe?????????

John T
 
Yep, if it don't throw a spark once its conducting current but then you interrupt it (points open or you remove jumper to ground) the coil is badddddddddddddd

John T
 
Matt, such problems would drive me nuts too.

Just a thought: using a known good coil in this test, would it matter if the coil's housing is electrically isolated from the tractor ground or not?
 
(quoted from post at 21:11:11 06/01/14) wire shorted where it goes through the side of the distributor?
Click to expand...
+1, check the isolator in the side of the distributor where to coil wire connects. It HAS to be shorted there.
 
The case of the coil is not part of any electrical circuit. Whether it is grounded to the tractor or hanging in free air will not make any difference.

Since you have 12 volts on each side of the coil when the points are open and 0 volts on the distributor lead when the points are closed you know the distributor is working OK. The next question is what is the voltage on the battery side of the coil when the points are closed? We know the distributor side drops to 0 volts but if there is poor connection between the battery and the coil the input voltage of the coil may also drop way down. The voltage at the battery side of the coil should be within a tenth of a volt or so of the voltage at the battery when the points are closed.
 
Pardon my ignorance, but how is the high voltage circuit closed?
The induced high voltage in the secondary windings of the coil sends a current to the coil wire > cap center terminal > rotor > cap plug terminal > plug wire > plug (where it jumps the spark gap) > spark body > engine head > to ???
Should the circuit not be completed to the other end of the secondary windings of the coil?
Thanks a lot.
 
The Kettering system has points allow the coil magnetic field to build and then, when the points are opened by the distributor cam, the magnetic field collapses and a large voltage (20 kV or so) is produced. The capacitor has two functions: 1) it absorbs the back EMF from the magnetic field in the coil to minimize point contact burning and maximize point life; and 2) it forms a resonant circuit with the ignition coil transferring further energy to the secondary side until the energy is exhausted. the high voltage circuit is "grounded" to the battery through its internal connection (in the coil) to the primary winding. That winding is connected to the ignition primary wire from the ignition switch and through the above mentioned resonance with the condenser.
Jim
 
I NOTICE YOU SAID YOU HAD A 12 VOLT BATTEY AND WAS RUNNING A 6V COIL. WHY YOU NEED A 12V COIL THEN WITH 6V RESISTOR BETWEEN COIL OUTPUT AND POINTS. CHANGE THE COIL TO 12V AND SHOULD RUN WITHOUT ANY INCIDENTS. YOU CAN START IT ON THE 12V COIL, AND IT WILL RUN, BUT NEEDS TO BE CUT DOWN TO 6V OR WILL BURN UP POINTS INSTANTLY.
 
That is a fine explanation. Thank you, Jim.

Now, I have one further question to verify if I've understood you correctly. In an earlier reply in this thread you proposed the following:
QUOTE
Disconnect the coil to distributor wire at the through post on the dist. Connect that terminal end on the wire to a good condenser wire, and ground the condenser body. With 12v to the ign side of the coil, touch the lead and condenser wire to ground, it should spark a little, as it is acting as points. When you break this connection to ground, the coil should spark. If it does not it is a bad coil. This process eliminates the distributor all together. Jim
UNQUOTE

Will this test only work if one battery post is properly grounded to the tractor frame?

In other words, if one were to wire the distributor ignition from a battery standing on the floor, and assuming the distributor is electrically isolated form the tractor frame, you would never get a spark?

Thanks, Hendrik
Doubt whether these musings help Matt in getting his Super C running LOL
 
(quoted from post at 18:36:39 06/04/14) I NOTICE YOU SAID YOU HAD A 12 VOLT BATTEY AND WAS RUNNING A 6V COIL. WHY YOU NEED A 12V COIL THEN WITH 6V RESISTOR BETWEEN COIL OUTPUT AND POINTS. CHANGE THE COIL TO 12V AND SHOULD RUN WITHOUT ANY INCIDENTS. YOU CAN START IT ON THE 12V COIL, AND IT WILL RUN, BUT NEEDS TO BE CUT DOWN TO 6V OR WILL BURN UP POINTS INSTANTLY.
Click to expand...

No, not instantly. That's just silly.

I bypassed the ballast resistor to eliminate it as the cause of the problem. Just to test for spark.
 
(quoted from post at 18:05:24 06/01/14) This Super C quit on me, like I shut off the switch. No spark.

I've dealt with 100 no-spark problems, but this one has me baffled. We've gone through everything TWICE, still no spark.

1. 12V directly to the coil = no spark at the coil.
2. Known good coil and coil wire = no spark at the coil.
3. 12V directly to known good coil = no spark at the coil.
4. New points and condenser = no spark at the coil.
5. Another known good coil and coil wire = no spark at the coil.
6. 12V directly to the second known good coil and wire = no spark at the coil.
7. ANOTHER new set of points and another new condenser = no spark at the coil.

The rotor *IS* turning.

There is 12V to the coil.

Points are gapped at .020.

I've never seen one like this before. There's nothing else to look at or change. It just won't spark.
Click to expand...

no answers other than what's been posted for you, but just to relate.
Had a similar problem on a external coil modded magneto
recently.
Went thru all the standard tests and known good parts swapping routine just like you.
Stone simple setup and passed ALL tests. Still no spark at the points. impossible...it HAS to spark LOL
I had a spare distributor/coil setup on the bench, so swapped the whole works and it runs fine.
I have the problem one on the bench and I WILL figure it out.
Please post your success when you find your culprit.
 
With battery on the floor, a wire from the positive post to the positive coil terminal, and a wire from the negative coil post to a condenser lead. A wire connecting the condenser body to the negative post of the battery. And a coil (high voltage wire coming out of the coil tower, and set 1/4 inch away from either battery post will spark if the lead from the condenser (attached to the wire from the neg coil terminal) is scratched on the negative battery post.
Do not do this on a battery with vents it could go boom. But that is the answer. Jim
 
Thanks again, Jim.
I understand how the current circuit of the high voltage windings functions.
I would like to do some experiments on battery+coil+distributor ignition systems. Need to visit a salvage yard for some parts since I only have magnetos on my vintage engines.
 
Ok, I feel stupid.

It was the SWITCH.

My bypass wire was no good on top of that, so it sent us on a wild goose chase all afternoon.
 
Your posts back in the first half of this thread all say you had voltage at the coil. Maybe you need a new voltmeter
 
Nope, voltmeter works fine. I for sure had voltage at the coil.

All I can figure is it must have been a high-resistance connection.
 
I think we have all been fooled by assuming that when the voltage is good in a circuit with no load that it will be OK when a load is added. When I need to check a questionable circuit I have an old head light that I use to put a load on it and then check voltage drop.
 
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