Still Stumped - 9N has no spark

1. I went back to the old round can coil configuration I had when I bought the tractor using a *cobbed* up square coil to cover the distributor and make contact with the points and distrib cap.

2. I removed the distributor and tested continuity from the point terninal screw across the points when they were both open and closed. Just to make sure there were no *shorting* issues.

3. I ran a wire from my *new* ignition switch to the pos(+) side of the round coil and a wire from the neg(-) side of the round coil to the terminal on top of the old square oil.

4. I put in a new coil wire coming out from the square coil to the round coil and tested all contacts (points and cap) for good continuity.

5. I bought a new set of wires, cut them to fit and tested contacts for continuity.

6. I have ~10 V at the coil when points are closed, and ~7 V when the points are open.

7. Installed new battery cable terminals.

I took one of my new wires and hooked it up to one of the nipples on the distrib. cap, and inserted a new spark plug with a wide gap. Placed the plug near a good ground spot on the tractor. But when I cranked the engine over, no spark.

I'm stumped and starting to grasp at straws. Think'in about installing a Petronix electronic ignition kit to elimiate the points from the equation completely. Don't know what to do.

HELP!!!

Remove the cap. Turn the engine until the points are closed. Connect a plug lead from your coil to a spark plug. Hold the plug to ground. Now, have somebody upen the points with a non-conductive tool (you don't want to use the blade of a screwdriver; use something plastic so you don't actually keep the circuit closed.)

Do you get a spark at the plug when the points open?
If "no", the problem lies in the low-tension (primary) side (points, distributor cam lobes, condenser, wiring, resistor, etc.)
If "yes", the problem is in the high-tension (secondary) side (cap, rotor, wires, etc.)

New Cap, Rotor, Condenser, Points, Coil (Napa IC-14SB), and plugs.

I took a reading where the voltage at the coil was ~12.5V (roughly battery voltage) and when I cranked the engine over (took a couple of tries) I saw the voltage at te coil drop to ~7V.

As for the inulator:

When I had the distrib off the tractor, I took my pos(+) voltmeter lead and clamped it to the points terminal screw (top of dist. above insulator) and took the neg(-) lead and placed it on the points. When I turned the shaft and the points separated the voltmeter did not show continuity of the circuit, there was a break (needle was still at 0). If there was a short or grounding problem, I would have thought I would have still seen a continuity reading. When I turned the shaft more and the points came back together the voltmeter showed the circuit was closed (needle moved all the way to the right).

Does this prove that the insulator (or points for that matter) does not have a ground/short problem?

Not sure if this is going to help, but my next step is I have taken the battery, distrib, coil off the tractor and I am going to sit down at a bench and wire it all up and see if I can see a spark at the points, dist. cap and take some voltage readings as well.

Does this sound plausable?

Yer reporting 7-volts? points closed? DO NOT USE ENNY RESISTORS with real 12v ignition coils. UNDERSTAND? Resistors are the ONLY reason or way you can read 7-volts. 7-volts ain't enuff volts to make a 12v coil sparkle. You say you don't have a resistor? Bettcha its in yer weaksister ignition switch contacts. $10 (cheap)..... ...Dell, yer self-appointed sparkie-meister

For the last week or so, you have been on an ignition switch tear, Mr Dell(WA).

I will double check my readings again.

I don't have any resistors inline to the coil. If there is one in the swithch, then that's a new one on me. I believe the coil has an internal resistor as it reads "Do Not Use External Resisitor".

At the round can coil input terminal I get a ~12V reading. At the top input terminal of the old square coil, which is gutted and used only to make the primary and secondary contacts, is where I get the ~7V reading when the points are closed, 12V when points are open. Again, I will double check this as you state it should be closer to zero.

I'm a bit confused, however, it's not the first time.

When I used the original frontmount configuration with a true sq. coil. I got read 10V with your secret resistor with the points open, and it dropped to around 7-8V with the points closed.

Wouldn't the that hold true now, even with a round coil?

Thanks again.

That voltage is wrong... it must be ZERO. The only resistance at that side of the coil should be the Points and when they are closed the connection to ground is complete.

Bench test and measure.. remember the Bolts on the Dist provide the ground for the Points
Plate and they must be tight.

Rememebr.. the oem resistor was back at the dash wire terminal.. is it still inline?

7v on a 12v coil.. I doubt it would fire too...

Soundguy

At some point you might want to run the distributor, cap, rotor, and coil into a starter/generator/alternator shop (not necessarily an auto parts store) and have them put it on their test bench. They can tell you what for quick and easy.