Looking for input, spark problems...

Bfish21

New User
1952 8N Ford
Side mount dist.
6 volt system, + ground


Heres the scoop,

Grandpa gave me the tractor last year and said I had to restore it.. He bought it in 1952.

Fast forward to now and it's re painted and re wired.
(Re wired because a few were burnt or bare or bypassed)

Tractor ran when I drove it into my shop.

I have power at the coil with key on, power at the points when they're open.. no power on the (+) side of the coil when they are closed. I have it gapped to .025. When I pull a plug and leave the wire on and hold it to the block there is NO visible spark.

I double triple checked the gap. There is power at the points (it's not grounding on the side of the dist) It is a new coil and new plug wires. And it is 1,2,4,3 firing order.

I've searched this site and found lots of trouble shooting but I'm still not getting anything.

I hope I answered all the questions you might have, thanks in advance!

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The spark occurs at the instant the points go from closed to open.

Rotate the engine so points are closed, then open them with insulated something, should spark at that instant.
 

You mean with the cap off and the points closed, manually open and close them and see if it sparks at the point? Yes it does that.
 
How is the cap and rotor? The carbon piece in the cap, and the contact on the rotor good? Any possibility of moisture in the cap?

Could the spark be going to ground through a carbon tracked cap or rotor?

The way you have described the electrical, it should be sparking. Question is, where is the spark going? Either to ground or getting lost before getting to the plug wires...
 

The cap and rotor seem good, I have hit them with fine sand paper. Moisture isn't a problem. Could I remove the center wire in the cap and see if that throws a spark before it gets to the rotor? I'm just trying to track this down without throwing money at parts.

Another question.. I saw an electronic ignition kit today to replace points? Worth it? Or don't fix what isn't broken?
 
On the 5 nipple distributor caps I always say this

#1 check that you have good blue/white spark at the center wire and then the 4 plug wires. Spark has to be able to jump a 1/4 inch gap or more. If you have that good spark at the coil wire but not the 4 plug wires then your cap and or rotor are bad. You can have a crack cap or rotor but not see it. One way to test for a crack cap is this but you will only do it one time. Gap the cap and at the same time try to start it. If you have a cracked cap your likely to jump 10 feet because it will zap you.
I learn that years ago when the local shops could not figure out why my dad truck would not run. I grabbed the cap when some one was trying to start it and I got a heck of a shock. Replace the cap and ran fine
 

So I just checked spark at the coil wire like you described. It is a very weak, not very often spark, but it is blue/white!
So what's this mean? Gap is wrong?
 

If the gap is wrong then I'm doing it wrong.. Here's how I do it

Remove cap and rotor
Bump engine till the squarish shaft would be opening the point
Loosen screws and put my .025 feeler gage between point and...other side
Get it so it has a light drag on the gage
Tighten screws back up and put cap and rotor on
 
Try using a jumper wire from a metal ground to the coil tower. It doesn't have to be a high voltage wire, a regular piece of wire will work. Coming directly out of the coil, there should be a hot spark, should jump 3/8 inch easy.

If you get a good spark out of the coil, there has to be a "spark delivery" problem between the coil and the plugs.

If not a good spark from the coil, do some back tracking. Try putting the old condenser back in, try the old coil.

All the point type ignition parts are now aftermarket, supplied by the lowest bidder in Bangladesh, so anything is possible. New bad parts are common.

About the electronic conversions, I have had no problems with them. They are very dependable, and a good fix for a distributor with loose bushings. The only disadvantage to the electronic conversion is they are polarity and voltage sensitive. If you go that route, be sure to order the right one, and be careful jumping, charging, and connecting the battery properly.
 
I want to add... Check the spark with the ignition on while manually operating the points. That's when you will get a good spark.

If the spark is good, then try a cranking spark check. It is normal for the arc to be greatly diminished, probably down to 1/4 - 3/16 inch. With a 6 volt, everything has to be right to get sufficient spark when cranking. If anything is wrong, partially discharged battery, too small battery cables (need to be size 0 or larger), or a dragging starter will steal away the voltage necessary to power the coil.

Also, do an accurate voltage test on the coil terminal. With the points closed, ignition switch on, check the voltage from the - terminal (ignition switch side) to ground. It should be within about 1/2 volt of the across the posts of the battery voltage. If it's low, could be a bad connection somewhere, too small wire (14 ga or larger), or a high resistance in the ignition switch.
 

I definetly get 6 volts at the coil on both sides while the point is open.

When the point is opening and closing there is a good spark.

I get weak spark at the end of the coil wire in the dist.
 

If I'm doing your ground wire to coil test correctly, it is a weak spark. Basically have to touch the wire to the post to get it to spark
 
(quoted from post at 21:42:13 09/08/16)
If I'm doing your ground wire to coil test correctly, it is a weak spark. Basically have to touch the wire to the post to get it to spark

But when I touch it to the post i get a good spark.. Just not a big arc or anything 1/4-3/8 away
 
If your testing the spark at the coil wire going to the center of the distributor and it is weak and intermittent that tells me the points are dirty or corroded so some times they are completing the circuit and other times they are not.

The way a coil work is when the points open you get spark at a plug wire. When points are close in lay mans terms the coil charges up. Then when the point open that charge is sent to a plug by way of the rotor. So if the point do not ALWAYS complete the circuit you get a weak spark that is there some times and not other times
 
Are you pulling the center wire from the distributor cap and then holding is a 1/4 inc from the block some place??

Send me an e-mail and I can send you my phone number which may help you figure out where your problem is
 
I thought of something you might want to try.

If you have an ohm meter, take a reading across the coil + and - terminals with it out of circuit.

There should be about 1 to 1.5 ohms resistance. If you get up around 3 ohms, possibly you have a mislabeled 12 volt coil.
 

If I checked it right, I do indeed have around 3 ohms. So get another hopefully 6 volt coil this time around?
 

I would think a 12v coil should work on a 6v system.. But not the other way around.. I could be wrong. Just pulled out my receipt and I definetly ordered a 6v coil, but with no markings on it I can't really prove it besides the 3 ohm reading
 
So it ohm'd out at 3ish. So i figured it was a 12v coil. Went to Napa and grabbed a new one. Swapped them out and got 1.5 ohm. Fired right up!

But when I pulled the other coil out it says "6v" right on it ... Maybe the ballast went bad?
 
(quoted from post at 21:45:21 09/09/16) So it ohm'd out at 3ish. So i figured it was a 12v coil. Went to Napa and grabbed a new one. Swapped them out and got 1.5 ohm. Fired right up!

But when I pulled the other coil out it says "6v" right on it ... Maybe the ballast went bad?
hat ballast? Should not be a ballast on that tractor.
 
(quoted from post at 07:56:53 09/10/16)
But I'm sure there is a ballast resistor inside the 6v coil..
ut that sucker open & post a picture of the ballast resistor for all of us to see! :lol:
 
(quoted from post at 09:19:06 09/10/16)
(quoted from post at 07:56:53 09/10/16)
But I'm sure there is a ballast resistor inside the 6v coil..
ut that sucker open & post a picture of the ballast resistor for all of us to see! :lol:

From what I learned that's the difference between a 6v and 12v coil. If I were to use a 12v coil on my 6v tractor I would need an external resistor.
 

But what I'm getting at is the coil was putting out twice as many ohms as it should have been. So some type of resistance was not being met.
 
Ohm is a measure of resistance and the higher the ohms of a coil the more voltage is takes to make a good spark.

NO coil has a built in resister the higher resistance is made by being wound differently.

A 6 volt coil on 12 volts will produce a real good spark but a true 12 volt coil on 6 volts will produce a very poor spark.

Sort of like if you tried to use a 6 volt bulb on 12 volts the bulb burns out real fast. Or if you try to use a 12 volt bulb on 6 volts the bulb is not going to be very bright. Coils work pretty much in the same way
 
(quoted from post at 14:28:07 09/10/16)
(quoted from post at 14:22:30 09/10/16)

How do you test for a bad coil? After I replaced the new coil with another new coil it ran great.
ou have completed the test and found the good one and one that is no good for your application.
 

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