ignition wiring question on 8N

The wire from ignition switch, does it go to the Pos or Neg pole of the coil?
Another way to state this, the wire from coil to distributor, does it come from the pos or neg pole of coil?
AND, what happens if you get this reversed? Could this cause tractor to start but always die within 1 minute of starting?

Which battery cable goes to ground? If positive ground, positive terminal of coil goes to distributor. Negative ground, negative terminal of coil goes to distributor.

Is your tractor 6 volt pos ground or 12 volt neg ground. And no reversal will not cause the tractor to die in 1 minute. But restricted fuel flow might. Check you fuel flow.

See tip # 33 re your wiring question.

Wiring it backwards will not cause the tractor to stop running in 1 minute.

You could have a spark issue.


You could have a fuel issue.


Don’t guess. Troubleshoot. See tip # 13 at the link below.


You need to answer 2 questions before you do anything else:


With the bolt in the carb bowl removed and the gas on, will the fuel flow fill a pint jar in less than 2 minutes?


Next, get out your adjustable gap spark checker * , open the gap to 1/4", hook it up, turn the key on and crank the engine. Does the spark jump 1/4"? Post back with the answers.


And do not buy a new part for the tractor until you can answer this question: how do I know the part on the tractor is defective?

Once you narrow the problem to spark or fuel, post back and tell us what you found (and how you found it) and you will get plenty of help to get your tractor running.



* Don't own an adjustable gap spark checker? Buy one! Not a test light! Until then, take an old plug, open the gap 1/4" ground it to the head & look for spark. It’s not the color of the spark that counts; it’s the distance it jumps.

https://www.autozone.com/test-scan-and-specialty-tools/ignition-tester/oemtools-adjustable-ignition-spark-tester/10257_0_0?cmpid=PLA:US:EN:AD:NL:1000000:TLS:71700000043798748&gclid=Cj0KCQiAovfvBRCRARIsADEmbRKBdAvAmtFfOvYiYXR7T6NYiW57uyv5-dEKjVT_h2KogQNUUMsRixYaAlU3EALw_wcB&gclsrc=aw.ds
75 Tips

Yeah, I just removed the fuel tank and cleaned it out. Not much rust etc in it, but fingers crossed that this was the problem. Apparently I did not have the coil hooked up backwards, but what would happen if I did? (its a positive ground, 6 V tractor)

Theoretically, a slight reduction in secondary voltage.

Realistically, on a 23 p engine.........nothing.
75 Tips

NO to your question. Mucked up wiring is the #1 non-starting/running issue, fuel 2nd. Coil has one terminal on front mount. OEM Ignition switch has a red w/green tracer and a yellow wire. Red goes to RH Ballast Resistor, Yellow goes to bottom terminal connection on ballast. The wiring diagrams are shown in several ESSENTIAL MANUALS - got them? No? So ya wanna be an N-Owner? The most important tool to invest in are the manuals. Read religiously. Sounds like you have the side mount distributor with two posts on coil. Can you read a wiring schematic? While waiting to get your copies, see here:

FORD N-TRACTOR FRONT MOUNT DISTRIBUTOR:

HOW TO SET TIMING:

RESULTS WHEN UNIT IS MOUNTED 180° OFF:

FORD 8N TRACTOR WIRING DIAGRAMS:


FORD 8N-SERIES TRACTOR OEM 6V/POS GRN WIRING PICTOGRAM:
FORD 8N TRACTOR -48/50 GENERATOR BELT TENSION ARM 8N-10145:

*Used only on early 8N generator with the front mount distributor.


FORD TRACTOR FRONT MOUNT DISTRIBUTOR FIRING ORDER; 1,2,4,3 CCW:


Breaker Points/Front Mount = .015"/Side Mount = .025" - Spark Plugs H12 14mm .025"-.028"; Firing Order: 1, 2, 4, 3 CCW.




FORD 8N TRACTOR ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS:




Tim Daley(MI)

1) Yes, it fills a pint jar with gas in less than 2 minutes (and, prior to that test, I removed and cleaned the gas tank out...didn't have much loose stuff in it at all).
2) Bought the adjustable spark tester.
2) Started the tractor, and it starts right up, runs strong but missing badly--fiddling with the choke keeps it running to some extent, but inevitably it dies in less than a minute.
3) Then I employed the spark tester and no spark at all, no matter how small a gap I make.
4) I think this is what always happens--after sitting for days it starts, runs "strongly" but missing badly, and dies in less than a minute. After that it always fails to fire again at all--I think the spark always disappears completely after one of these abortive, less-than-a-minute runs. After this it won't fire again for at least hours, if even on the same day.
What's next?
Thanks for the help, by the way!

Run a jumper wire from the battery to the coil. Press the starter button. Do NOT leave the jumper in place with out the tractor running.

Post back with results.
75 Tips

That will eliminate ign key or resistor problems.

Symptoms also could be coil on the way out. Check the other stuff before you throw $$$ on a coil.

Okay, did that. Ran a jumper wire from battery to the coil. Seemed to make no difference. Fired a few times but woudldn't start. Then tested the spark again (without jumper wire) and again, zero spark, no matter how small the gap. Carb is brand new, BTW.

What is your points gap?


Confirm that you have voltage to the coil. Battery voltage, points open. About half that if the points are closed.




Do you have battery voltage across the points when they are open? (with the points open, put one probe on one side of the points & the other probe on the opposite side of the points) Verify the gap on the points at .025. Then, dress the points by running a piece of card stock or brown paper bag through them. New points sometimes have an anti-corrosive dielectric coating on them & old points can corrode or pick up grease from a dirty feeler gauge or excessive cam lubricant. (I always spray my feeler gauge blade off w/ contact cleaner.) Make sure you have voltage across the points, as in past the insulator on the side of the distributor. That is a very common failure point on sidemounts, along w/ the attached copper strip. It's hard to find a short there because it is usually an intermittent . So 'wiggle' the insulator & the copper strip a bit when you are doing your checking. If you find the short there, the Master Parts catalog lists everything you need on page 154. You can make the strip and you could also make the insulators as well. But, somethings are just easier & in the long run cheaper to buy. Get the strip, 12209, screw 350032-S, 12233 bushing & 12234 insulator & just replace it all.





If you just replaced the rotor & lost spark, put the old one back in. Insure that the rotor fits firmly on the shaft & that the little clip is there. Make sure the distributor cap is not cracked, doesn’t have gouges in it from the rotor or brass shavings & doesn't have carbon tracks. Check continuity on the secondary coil wire. Make sure it is firmly seated in both the cap & the coil. Next, remove the secondary coil wire from the center of the distributor cap, turn the key on & crank the engine while holding the end of the wire 1/4" from a rust & paint free spot on the engine. You should see & hear a nice blue/white spark. If not, you have a bad coil or condenser. Just put the old condenser back in to eliminate that as a possibility.
75 Tips