Points next?

[Chris623]

My spark plug wires fit my spark plug tightly (as they should) but are way larger than the top of this tester.

 

[Eman85]

(quoted from post at 10:20:09 08/20/23)
I checked the test light to make sure it was working. Then clamped the test light to the end of the wire that went into the distributor and touched the other end to the engine. No light. Turned on the ignition and no light. Pushed the starter and no light. Don't see how setting the tester to 1/8" will show me anything if I'm not getting enough juice to light the light bulb.

Let's go slower. I mentioned dropping the gap down on the spark tester because it would show you a sign of a weak coil possibly if it wouldn't jump the 1/4" but would jump the smaller 1/8" gap.
I take it you do have a bulb type test light from what you posted. If you don't have any power/voltage at the coil you can't make spark so it would be time to go upstream to the ignition switch and see if you have power at the switch and flowing through it when the switch is in the on position.

Your spark tester doesn't care which direction you connect it. You can hold the end of that coil wire 1/4" from the block while turning the engine over and see if the spark jumps the gap. You do stand the risk of you becoming the spark tester when you do this, but that is part of learning. It won't hurt you just give you an idea of how much it takes to jump the gap. Most of us have experienced this usually at a young age working on lawnmowers and many times from a friend or relative having us hold the wire while they pull the rope.

This post was edited by Eman85 on 08/21/2023 at 08:15 am.

 

[lastcowboy32]

(quoted from post at 13:46:45 08/20/23) The brass end (left) is designed to plug into any one of the sparkplug wires. Stick that end into the plug wire in place of the sparkplug.

That is the exact tester that I have. I like having the jumper wire attached.

When I troubleshot my 3000, which has a side distributor like this 8N, I was able to drop the coil from its bracket, plug this tester into the top of the coil, then clip the jumper wire to the block and test right at the top of the coil. No mystery. No wondering if it's the coil, the coil wire, the connection to the distributor... it's the definitive test of whether the coil is working.

But... I see that the troubleshooting here started with...something about the screw on the bracket to holding the coil was too rusty, etc.

We can buy eggs at the store... but eggs must be cracked to make omelettes.

Hopefully, the racecar building friend diagnosed this issue in about five minutes.

 

[Chris623]

That's funny but that's the point. Ya gotta know up front the eggs have to be cracked. I admit how little I know about all of this but I don't mind being ribbed about my lack of knowledge. :wink:

Appreciate all you guys having to patience to deal with me. I learn something new every time I come up with a new problem and you walk me through it.

 

[lastcowboy32]

(quoted from post at 12:35:11 08/21/23)
That's funny but that's the point. Ya gotta know up front the eggs have to be cracked. I admit how little I know about all of this but I don't mind being ribbed about my lack of knowledge. :wink:

Appreciate all you guys having to patience to deal with me. I learn something new every time I come up with a new problem and you walk me through it.

Indeed. Your late friend and your racecar building friend would look at that screw and make a decision based on wisdom, gained by experience...

...how many of those screws have they messed with and
how many turned into three hours with a drill and an easy out... vs
where can they clip the spark tester to avoid messing with it... vs
what are the chances that the coil wire itself is the problem...

I don't worry too much about screws. I'll drill the little &@*$# out in a heartbeat, if I think they are in my way.

But...that's just the level of shop stuff I have available.

On the other hand? Ask me about the Sunday that I lost yesterday, trying to get a sprocket off of a rusty shaft in one piece to replace a bearing. The bearing took about five minutes. The sprocket took hours, with a torch, hammer, chisel, various prying implements, impact wrenches... If I had a "phone-a-friend" for that... I would have dialed that dude up.

I can understand how a rusty screw would be a deterrent to somebody that just wants their tractor to be running.

 

[lastcowboy32]

On a practical note, if you ever think about doing this in the future, a spark plug wire can work as an adapter from the top of the coil to the spark tester. It should have the male end to go into the top of the coil (because that looks like one of the distributor ports).

One of the things I had at my disposal when I spark tested my 3000, was a brand new set of plug wires. I had a brand new plug wire at my disposal as an adapter from the coil to the tester.

 

[Chris623]

Thanks, good tip.

 

[Chris623]

JMOR,

Is the picture you showed the tester you use? If so, does the brass end fit a spark plug wire on the 8N? I sent mine back because there was no way the wire would clamp onto it like a spark plug.

 

[JMOR]

(quoted from post at 19:44:22 08/21/23)
JMOR,

Is the picture you showed the tester you use? If so, does the brass end fit a spark plug wire on the 8N? I sent mine back because there was no way the wire would clamp onto it like a spark plug.

t is the one that I have, but I don't think I ever used it except on the bench, so I can't answer your question. I really bought it out of curiosity, as from ~12-13 years old, I just held the wire close to some metal part of engine and looked at the spark.....just like my Dad did.

 

[Chris623]

Okay, thanks.

 

[Chris623]

Well, my buddy came out to the place today and we worked on the tractor. He finally agreed the coil was bad. Went out and bought a new one. Installed it and while there's juice all the way to the coil, there's no fire coming out of it. I used my jury-rigged variable spark tester to test it. Tractor just won't start. I'm at a total loss. I'm beginning to think the only way I'm going to solve this is to take a shovel up to the cemetery and dig 'ol Carl up. Better not.........I don't think Wanda (his widow) would like it. I'm really disappointed. Thought I was going to be mowing tomorrow.

This post was edited by Chris623 on 08/23/2023 at 04:13 pm.

 

[Chris623]

My buddy who helped me yesterday just sent me an email saying while he was working with all of that, he thought the distributor cap looked like it needed replacing and suggested I buy a whole new kit. Cap, rotor, points and condenser. Is that going too far?

 

[Eman85]

(quoted from post at 16:11:04 08/23/23) Well, my buddy came out to the place today and we worked on the tractor. He finally agreed the coil was bad. Went out and bought a new one. Installed it and while there's juice all the way to the coil, there's no fire coming out of it. I used my jury-rigged variable spark tester to test it. Tractor just won't start. I'm at a total loss. I'm beginning to think the only way I'm going to solve this is to take a shovel up to the cemetery and dig 'ol Carl up. Better not.........I don't think Wanda (his widow) would like it. I'm really disappointed. Thought I was going to be mowing tomorrow.

This post was edited by Chris623 on 08/23/2023 at 04:13 pm.

Did you test for power to the coil BEFORE replacing it? Do you have a test light? Connect the test light to ground and touch the side of the coil that has the small wire that goes to the distributor. With the ignition on and spinning the engine over the test light should blink on and off indicating the points are making and breaking the circuit. No blinky no sparky!
Remember the bit about science class and the collapsing of an electrical field?

 

[Chris623]

Yes, I have a test light. I don't have to disconnect that wire from the coil, do I?

 

[lastcowboy32]

(quoted from post at 16:11:04 08/23/23) Well, my buddy came out to the place today and we worked on the tractor. He finally agreed the coil was bad. Went out and bought a new one. Installed it and while there's juice all the way to the coil, there's no fire coming out of it. I used my jury-rigged variable spark tester to test it. Tractor just won't start. I'm at a total loss. I'm beginning to think the only way I'm going to solve this is to take a shovel up to the cemetery and dig 'ol Carl up. Better not.........I don't think Wanda (his widow) would like it. I'm really disappointed. Thought I was going to be mowing tomorrow.

This post was edited by Chris623 on 08/23/2023 at 04:13 pm.

Your coil has three connections:

DC + (also called primary +, positive...)
DC - (also called primary -, ground...)
Secondary... (which is the booted cable to the top of the distributor)

I attached a diagram:
red is DC+
green is DC -
yellow is secondary.

You can have power at DC+ AND have a good coil AND have no spark.

How?

DC- isn't really "ground"... it goes to the points...the points are a switch that connect DC- to ground intermittently.

So, if your points never close... no spark
If your points do not have a good connection to chassis...no spark
If your points never open... no spark

Creating spark takes both the coil and the points working together.

The theory of how a coil's primary and secondary work to create the spark because of the switching the DC- to ground intermittenly by the points is something you can read on the internet. Your friend should understand that as well.

 

[lastcowboy32]

If your points are so corroded that they practically don't open... no spark

Hopefully, you are getting the point that the points are really important , working with the coil, for spark generation.

 

[lastcowboy32]

If that connection shown in green isn't there..
or if the terminals are bad...
or if the wire is corroded and bad...

No spark

 

[Chris623]

Thanks for going to the trouble to explain that lastcowboy32.

 

[lastcowboy32]

Welcome... I feel as though you were owed a little bit more explanation, though.

My previous comments made it seem as though it's straightforward to troubleshoot back in a single line from the top of the distributor to the top of the coil...etc. But, that's only the coil's secondary side.

To troubleshoot the primary side, it isn't just power at the DC+...you also have to look at the DC- to distributor and the points.

Because it takes two things on the coil's primary side.

It takes power at the DC+ from the key or ignition switch.

AND

The DC- connection has to be switched to ground intermittently (essentially one switch cycle per spark) by the points.

 

[Chris623]

Thanks for that.

Say, I'm trying to figure out where all the juice from the battery goes. There's a White "thing" under the dash that resembles the silhouette of the Alamo. One terminal is hot......(all the time).......but I get nothing out of the other side. What is that thing and should both terminals be hot if the juice is going to get to the coil?