Still No Spark 1950 8N 12v conversion.

[2LateIWon]

So I've had this tractor for a over a year now and have never had this much problems with it.

So I've replaced points and condenser. No spark changed coil. (it was getting really hot and leaking oil out of the top and it was pretty old so I replaced it anyways) still no spark, Replaced resistor ballist, still no spark replaced wires going from resistor to coil and coil to distributor. Still no spark. I have 12v to resistor. After resistor I have almost 6v. I have almost 6v to the distributor. If I take off the wire from the coil to the distributor it stays @ 12v. So I'm thinking it's the condenser. I switched the new condenser with another new condenser. Still no spark. I need to get this running so I can sell it.

What should I do?

Thanks

 

[V1Rotate]

Try running a hot wire from the positive battery terminal to the positive terminal on the coil. That will eliminate all the wiring and the resister circuit.
If you still don't have any spark, double check the connections between the points and the condenser to make sure that nothing is grounding out. Also double check that the point gap is correct.

Hope this helps

 

[J_J]

When you apply 12v to the coil with the points closed , the coil builds up a large field,and when you open the points, the field collapses and the high voltage spark is sent to the plug. The capacitor is there to help keep the points from arcing. You can test the coil with some wires. Remove the high tension wire and lay it close to the block. Apply 12v, and then use a screw driver, short the points and then let off. A blue spark should jump from the high tension to the block every time you short the points and let off.

Check your plugs.
Check your plug wires.
Check the high tension wire to the distributor.
Check the cap.
Check the points.

 

[2LateIWon]

Thanks guys!!!
I jumped the coil and there was a small spark (I have the battery charging now after me keep trying to test and crank it) from the coil wire. I grounded the dizzy wire and held the coil wire close to a ground and then let off the dizzy wire and it made a small spark. Shouldn't it be a big bright spark? specially since it's right off the coil? I wonder if that new coil is messed up and not producing enough spark energy to do anything.
Thanks again for the help and I'll make a jumper wire and try it out.

 

[2LateIWon]

So I jumped the coil and still nothing. (It did spark a little when I touched it to the coil but I figured it was because I was going from 6v to a full 12v) I made sure nothing was grounded. Still nothing :-(

 

[J_J]

Is your coil any good? Yes, you should get a fat blue spark.

 

[Argosy]

Make sure all the wiring on the points is in the correct position. When points were the norm on cars I've seen sets were the wiring was grounded to the points frame.

 

[2LateIWon]

I think it was just really bright outside. I hooked up another coil and it was about the same. Yep it's hooked up right. (as far as I know)

 

[Soundguy]

dizzy feedthru bushing is the next thing to check, assuming the points are opening.

make sure the copper strip from the feedthru bushing is not touching the side of the dizzy too.

soundguy

 

[2LateIWon]

from just looking I see nothing touching so I checked the ohms and it read 0.1 (going from wire on out side of dizzy to base or out side of dizzy)so I'm going to check again in the morning and make sure the points aren't closed. (forgot to check while I was bringing my tools in for the night. (hey glad to see ya over here too Soundguy I just started using this forum recently. Your always such a big help)

 

[J_J]

If your points are fully closed, you will not get a spark, as the opening of the points is what completes the spark cycle. If the capacitor is shorted, the same thing.

Did you say you were using a 12 v coil? I believe in the start mode, you apply the full 12 v to the coil and after running the voltage is dropped down via the resistor. Some coils have a built in resistor, and others were external resistor.

 

[2LateIWon]

Cool So I got spark now but still not starting But I'm super happy about that.
Yeah some how the bolt doing through the distributor was grounding out. So I'm getting spark now. Now I need to figure out why it's not running now. I need to check fuel or maybe even make sure I haven't crossed the wires some how


Thanks for all your help

 

[2LateIWon]

So Still getting fire (wooo whoo) but it still wont start and it's back firing sporadically. I didn't mess with timing or anything and the cap will only go on one way

 

[TedLaRue]

So Still getting fire (wooo whoo) but it still wont start and it's back firing sporadically. I didn't mess with timing or anything and the cap will only go on one way

Could you have mixed up the order of the spark plug wires? Firing order is 1-2-4-3. This website has a picture showing the correct connections (second image labeled "Engine Detail - Right Side"). The plug wires must be in the correct order, and also in the correct positions (assuming you haven't pulled the distributor out).

A cracked distributor cap (or one that is really dirty on the inside) could also cause that kind of backfiring behavior.

The point gap also affects timing to some degree, but probably not enough to keep it from starting.

Gotta say, I'm impressed by so many previous posts being right on for a 60 year old ignition system, including J.J.'s clear explanation of the theory, and SoundGuy's super-intuitive suggestion about the through-the-distributor-wall bushing allowing a short (which, if I understand 2LateIWon correctly, was actually a problem).

 

[2LateIWon]

That just goes to show you that you can have all the book smarts in the world but experience is priceless.

I never took the wires off except when I change for a new cap and rotor and I did it one by one. So it is possible I had the cap turned 180*

And I hope you guys know how appreciative I am. I'd work more on this thing more consistently but it's been well over 100* (actually yesterday was a cool 103* compared to the 107* and greater we have been getting. 2 sat ago it was 110*)

 

[Soundguy]

yep, prop the points open and then check continuity.

post back

soundguy

 

[2LateIWon]

I'm stuck here at work but after work I'll run outside and check it. I will say after I loosen up the through bolt it wasn't grounding out. And I was getting spark. woo whoo
It's just trying to back fire everynow and then now. So I'll recheck the spark plugs and firing order to make sure I didn't cross them up.
Thanks again

 

[Soundguy]

1-2-4-3.. #1 is at the front.

make sure poitns gap is .025 on all lobes on the the side mount.

soundguy

 

[2LateIWon]

Ok Firing order is correct. and gap is good...... after about 5-10 seconds trying to start nothing after the 3rd or 4th try I get a back fire. I don't get it.

 

[J_J]

Sticky valves will allow back fire to occur by not closing at the right time.

You might also have some cross firing in the cap. or the spark plug cables are arcing to each other.

Have you done a pressure check on the cyl?