8N Spark Plug Help

We have an 8N that's been converted to 12v. So far, we've replaced the battery, ignition switch, and solenoid. But in working with those, we accidentally moved the spark plug wires and they got eaten by the belt on the alternator. None of our local stores had the right set or could even order them so we resorted to making our own. The local car parts place sold us silicone core 7mm wire and we made our spark plugs. However, now that we've made and installed them, we still can't get it to start. Battery and alternator both tested good and it'll turn over but we're not getting spark. I was wondering if maybe it's the silicone wires? Will an 8N work with silicone core wires for spark plugs? The old ones were copper but the auto parts store assured us that they'd work the same but I was hoping for a second opinion. Thank you for any help and guidance!

The wire coverings are silicon "rubber" covered, which is good. The core is either synthetic fibers with wrapped coils of thin wire around them
providing connection, or graphite impregnated fibers that conduct the spark. The wire wound are better, but both should work OK. the issue is
probably inside the distributor (is yours a side distributor, or front distributor? Jim

I thought that I had a spark problem also. I purchased an in-line spark tester at Harbor Freight for $4.99. I installed it on a plug and discovered that I was indeed getting juice to the plugs. I put gas in it and it started after a considerable amount of cranking. Turns out it was a gas delivery problem, not electrical. Being able to confirm that you are getting juice to the plugs is very important. Might help to buy the tester.
SDE

The problem with that $4.99 spark tester is that it's a light.

It takes about 22kv to fire the spark plugs in the engine. That light will come on at half that voltage giving you the impression that you have sufficient voltage to produce a spark in the cylinder. You don't.

A few dollars more will get you the tool you need: an adjustable gap spark checker:


https://shop.advanceautoparts.com/p/autocraft-ignition-tester-ac664/10051080-p?c3ch=PLA&c3nid=10051080-P&adtype=pla_with_promotion&product_channel=online&store_code=&gclid=CjwKCAjw5vz2BRAtEiwAbcVIL4fDqTvMHjNx-e_c_umSaUcxaVrCh2v0HYrR4Vy9WXQUWGKF2QxQ0xoCa6sQAvD_BwE&gclsrc=aw.ds
75 Tips

My birthday is next month. Hint hint

Carbon core/silicone covered spark plug wires work well if you have an electronic ignition, copper core otherwise.

You can get good copper core plug wires from a few suppliers- just have to search. Firing order is 1,2, 4, 3 and can be found in your Essential Manuals. By 'solenoid' do you mean the starter motor solenoid? The neutral safety starter pushbutton near the gear shifter isn't a solenoid. You verified those parts were defective before you bought new ones right? 90-95 percent of all non-starting issues are due to incorrect wiring. Is the OEM Ballast Resistor in the circuit? It should be. Is the OEM Generator and Voltage Regulator removed from the circuit? They should be removed. Are you running a front mount distributor? If so, is your coil the OEM 6V unit? If so, did you add an external 1-OHM ceramic resistor to the circuit?
The Ford Angle (side) Mount distributor does NOT use the OEM Ballast Resistor.

FORD 8N TRACTOR WIRING DIAGRAMS:


FORD OEM BALLAST RESISTOR -USED ONLY WITH FRONT MOUNT DISTRIBUTOR:

HELP: The LH resistor Terminal Post connects to the COIL Stud Terminal Post as you face the back off dash. OEM Wiring is RED.


EXTERNAL 1-OHM CERAMIC RESISTOR - USED ONLY IF COIL IS 6V:


CORRECT FORD 8N ELECTRICAL SYSTEMS - 6V & 12V:


OEM 8N WIRING(6V/POS GRN) AFTER S/N 8N-263844 WITH ANGLE (SIDE) MOUNT DISTRIBUTOR:

*PICTOGRAMS courtesy of JMOR


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



Tim Daley(MI)