149 No power to coil
 

I recently pulled the engine out of my 149 for some work. New head gasket, flattened head (.001 won't fit under it :D), static timing on the points, and put a screen on the flywheel (PO hadn't had one on there). I put the engine back in on Saturday and it has no spark!
On the wiring diagram I noticed the points wire was on the wrong coil post so I moved it. It sparked exactly ONE time, when dad still had has hand on the spark plug tester and found out how 48,000 volts feels. Then it went back to having no spark. XD
Because the points wire had been on the wrong coil post, I thought the coil could have possibly been damaged, so I tried swapping in a spare coil. No dice. Next, I connected the + lead from my battery charger to + on the coil, then - on the charger to - on the battery. This still did not work. The starter generator has been rebuilt, solenoid, voltage regulator, ammeter, and condenser have been replaced, and I can verify the contacts on the points are closing and in good shape. The only obvious culprits besides the wiring itself are the coil and key switch. How do I test these parts? Any help would be appreciated, especially since I'm HORRIBLE with electrical parts.

Consult the wiring diagram for your tractor. It is important to properly connect the coil +/- with the points on - side of coil to ground https://www.onlycubcadets.net/forum/showthread.php?t=22

When the points OPEN, the magnetic field in coil collapses, thus producing a spark @ the spark plug.

Also, it's not a good idea to use a battery charger to provide power to coil....especially without a battery presented on the grid. That can harm the coil as the charger can spike voltage. Good idea to test the coil to see it falls within certain parameters: https://www.onlycubcadets.net/forum/showthread.php?t=11

I have had a brand new set of points cause a no spark condition, and yes they "looked good".
I would suggest switching back to a "known good" set of old points or try a different new set just to eliminate something so easy to overlook.

The points need to be cleaned as oil residue is present from the factory. Run a clean dolla bill through the contacts.

The points are not brand new. They are the ones that had been on the engine and had worked well. I did clean them when I did the timing and I can verify that they conduct electricity and are closing. I did a continuity test with a multimeter when timing the engine; points are not the issue

No power TO THE COIL??
Look at/test the ignition switch would be the first thing I would check.

A bad condenser will also give you a no spark situation.
Disconnect it and check for spark.
AND...
do you have the condenser on the same coil post as the points wire?

Yes, no power to the coil. I replaced the condenser this past summer. Shouldn't it last longer than 8 months??
Hot wire from the key switch goes to + on the coil, then both the condenser and points are tied to - on the coil. Is it even possible for the key switch to send power to the starter generator but not the coil when it fails???

I just a had a faulty spark plug episode. Thought I flooded it, pulled the plug, cleaned and back in. One or two fires then nothing again. Pulled the plug and when grounded I got about one spark every ten cycles. Held it just off ground and spark jumped from the plug body to the head. Cleaned an old plug and away I went. The plug was good two days ago. Points and condensers can be the same.

Well, the key switch is not sending power to the starter/generator.
The key switch is sending power to the starter solenoid.
When you turn the key to start or run, battery voltage is applied inside the switch to the wire connected to the coil.
When you turn the switch to start, battery is applied inside the switch to both the wire going to the coil and the wire going to the solenoid.
Therefore if the contact inside the switch for the coil wire is faulty, you get no battery to the coil.
So the simple answer to your question is Yes.
Corrosion the switch lugs can also create your problem.

Yes, it is possible. Starter and coil are on two different circuits in ignition switch. If they were on same circuit starter/generator would be on start continuously.
When starting, turn key just far enough to engage starter. Sometimes if ignition switch has worn contacts they will complete circuit if switch is not turned completely.

Also have you checked for battery voltage at battery terminal on ignition switch?

Me and Dad went through the wiring the other night and the key switch turned out to be fine; just some bad grounds. We're getting 12.5 volts to the coil now, but the engine still isn't getting spark. I cleaned and re-timed the points again, and got a new coil from O'Reilly. So, either I got a bad coil or the condenser isn't working. What should I do?

I suggested to you in post #7 to disconnect the condenser.
It's purpose is to reduce arcing across the points. The engine can run without one, just burns the points if you go long term without it.

Just remove the condenser lead from the neg side of the coil and give it a try.
If still no spark, you need a test light for easier further testing.

Got it. What do you do with the test light after that? We've got one that hooks onto the spark plug wire, if that's the kind you're referring to. Isn't it possible to test a coil with a multimeter?

Stick the test light to the neg side of the coil and crank.
It should flash.

Attach a wire to the pos terminal on the battery and the other end to the pos wire on the coil. Then turn the key and let us know what happens. If it starts remove the wire, don't leave it on or you will ruin the coil. This will rule out a bad ignition switch.

Ok, I took the new coil and measured the resistance according to the chart that was linked earlier. From the case to any terminal was infinite resistance; In spec. From + to the tower was 9500 Ohms; In spec. From + to - was anywhere from 3.1 to 5 Ohms. I couldn't get a steady number on that one.
The chart says + to - should be between 4 and 8 Ohms, and my number was noticeably lower. Does this mean my coil is shot?

What you have checks for high voltage output of the coil.
A test light (pictured) checks for voltage at various points in a circuit, in your case the key switch, coil, and points.

Your test procedure would be:
1. Remove the wire on the positive lug of the coil.

2. Attach the alligator clip of the test light to the negative post of your battery.

3. Turn your key to "on", touch the tip of the test light to the wire you lifted from the coil.
If light on, that section of the key switch is good.
If no light, the key switch is bad or the connector is not getting battery into the key switch.

4. If Step 3 gives you a light, turn and hold the key to "start". If light on, that section of the key switch is good. If no light, but you had light in Step 3, the key switch is bad.

5. If Steps 3 and 4 do not produce light on, persue key switch or connector problem.

6. If Steps 3 and 4 do produce light on, re-attach the wire to the positive lug of the coil. Attempt to start the engine, while it is cranking, touch the tip of the test light first to the positive lug of the coil,
then the negative lug. Both sides should produce a flashing light. The light goes on when the points are open, off when they are closed. If both lugs flash, the primary side of coil is good and points are good.

7. If no flash or a steady light on, remove the wire from the negative lug of the coil that goes to the points. Switch the alligator clip of the test tight from the negative battery post to the positive post.
Crank the engine and touch the tip of the test light to the wire going to the points. The light should flash, on when points close, off when they open.
If steady light on the points are not making contact when they close, if no light the points are not opening or are shorted.

What about your other coil? The current coil is out of specs on the +/- by roughly 25 percent but may or may not work..

It seems if you have power to the coil but Im still trying to figure out if your points are make and break. This is important. You seem to indicate that it is doing so. If it is functioning properly, then we have the coil by itself (see above), spark plug wire and spark plug to figure out.

Another test to do with your test light is put the alligator clip on battery positive and the probe on the - side of the coil. Crank the engine while watching the light. If it doesn’t flash on and off when the points open and close then the contacts on the points aren’t making up. Depending on what they were cleaned with could cause this because just a tiny bit of sandpaper dust can cause them not to make contact.

Just a thought, check to see it the wire from the coil-to- points is not grounded where it attaches to the points, it happens!
And, sometimes it grounds to the point cover because the gromet is missing where the wire enters the points cover. :bigthink:

UPDATE:
I managed to get the engine to run, and run well last night. Turns out, it [I]was[I] the points. I used Matt Gonitzke's method of static timing and it turn's out the points weren't closing quite enough to contact and charge up the coil, and that's why I didn't have spark. That's the last time I'll be fiddling around with timing. I'll stick to gapping the points at .020 like I did last night; way harder to mess up.
I ran the 149 with the points cover off in case I'd have to make any adjustments, and I was getting a nice, hot spark from them, even with the condenser wired in. The coil is definitely doing it's job this time around! :Kohler1::IH Trusted Hand:

Nice you finally found the culprit and it was a cheap fix.

But timing is still a better method than just gapping the points. Gapping gets you close and gets you by, but timing gets you there.

But I guess either method requires some effort at accuracy.

At last!!
Much easier to have dine this when the engine is out of the tractor and on the bench/stand.
Get it dead nuts right away and be done with it.

One thing I'll try is to vary the gap by .001 at a time and see if that helps at all. It is running very well at the moment, though.

Instead of by gap, you can set your timing by VOM: https://www.onlycubcadets.net/forum/...ead.php?t=4405