Newbie Ignition help

[Saucymynx]

Hello all,
Let me preface this post by saying I have spent the last two hours trawling through this and other forums as well as the Steiner parts catalog and I am as confused as I was when I started. I have a late model 140 serial number 44678. The tractor runs beautifully (until today). I have used it to plow and disc and today was running a sprayer off the PTO to spray my apples. It was running Great for about 90 minutes and then just stopped, as if I had turned off the key. It was low on fuel but not out. I topped the tank off but was unable to restart it. After reading a few posts here, I figured it must be the ignition. The coil was not hot but I replaced it with one I had lying around. The resistance on the one I took off was hi, about 18 ohms (primary). Still no luck starting. It cranks well. I did rewire the entire tractor last winter. I pulled the distributor cap and the contacts are a bit oxidized. When I pulled the center wire from the distributor cap and cranked, I could not see a spark. I figured time to replace the ignition parts.

This is where my question is: it seems that there are many different caps, rotors, etc.. I want to make sure that I order the correct parts. I cannot find a model number stamped on the distributor-I don't even know where look, and there is 40 years of gunk all over. I would greatly appreciate any help or recommendations pointing me to what brand and or model distributor tuneup parts I should look for.

I may actually be barking up the wrong tree and ignition is not the problem. As I think about this, this has actually happened a few times before where the engine would just stop. Letting it sit for a period of time allowed it to restart.

One last question–if I use a 12 V internally resisted coil, should I still use the external ballast resistor that is in place now. The tractor has a Delco 12 V generator

I would really appreciate any help that you could offer before I go and buy a bunch of parts that don't fit

Thanks

Renee

[Saucymynx]

i apologize for the multiple posts - not sure what happened!!!

[Bill Hudson]

i apologize for the multiple posts - not sure what happened!!!

Twitchy finger. Gotcha covered.

Bill

[SONNY]

IF coil has internal resistor, then no you dont use the external one with it---only resistor in the line.
Did you check your current resistor??? I have a dozen dead ones here!!---check for current passing thru it,---Mine have current TO them but not THRU them, so you might check that out just to eliminate/confirm a suspected part.

[Saucymynx]

Thanks Sonny. Like I said – I am a newbie. How do I check current through the resistor?

[MiCarl]

Just check voltage at the coil primary to ground. So long as you've got 12V there the resistor and key switch are good.

[Eugene]

Ignition points blocked open with sheet of paper, ignition switch on. Check the voltage at terminal on the side of the distributor. Looking for battery voltage. No voltage, start working back through the ignition wiring, junction to junction, until you find voltage. The problem will be the previous appliance.

Battery voltage to terminal on side of the distributor, remove the wire from the center of the distributor cap and place about 1/4" from engine block. Screwdriver jump across the ignition points. Spark, replace points, condenser, retime engine.

While you have the distributor cap off check the condition of the rotor and battery cap.

From your description it could be anything from a faulty switch, broken or loose connection, bad coil or points in the ignition system.

[MiCarl]

Eugene's description is better than mine. The answer I gave should only read 12V if the points are open.

[Saucymynx]

Thanks for all the advice-very helpful. I pulled off the rotor cap and cleaned the contacts. They were very corroded I. checked the voltages and had voltage up to the coil. I cleaned the coil contacts, as well as the point contacts. Having sat overnight, it actually started right up. I ran it for an hour under light load, and it died again. No sputtering as if it was a fuel problem–it just stopped. The coil, plugs, and wires look original, so I will at least replace those.

What do you all think about replacing the ignition with a solid-state Pertronics set up?

Any other ideas?

Thanks for your invaluable advice

[Eugene]

What do you all think about replacing the ignition with a solid-state Pertronics set up?

Don't do it. Why do it? What are you going to gain if you do it?

Any other ideas?

Solve your current no start, doesn't run, problem nest.

edit. next not nest

[Saucymynx]

Thanks for the reality check, Eugene! New "old school" parts on their way! I am so glad I bought the parts manual!!!

[Saucymynx]

Update. With all the great advise here, i went ahead and replaced the coil, points, condenser,rotor, distributor, plugs, and wires. She fires right up and purrs like a kitten! Time will tell if that fixes the shut-down issue. Thanks for all the help!