new thread - stumped

Ok, so I went to the local ford repair place and brought my distributor in thinking the bushings were worn. They checked them and compared to known good ones they had (distributors). Mine checked good (same minor movement as their spares).

SO he opened the gap of the points a little...reassembled...and put mine in a vise. Then he hooked up a battery pack to the vise and to the coil and rotated the shaft. He had a wire and plug hooked to the cap also. She sparked white every time.

I bring it home and install. I took a boot off of the engine plug...installed another plug in that boot and grounded it on the plug in the motor. Key on and starter button pushed resulted in no spark.

I checked power at the coil top - good. I put a light on the coil top and cranked with the key on. Bright light then low. This repeated so the points/condenser/ground all should be good.

I am simply not getting spark out of the plug wires at the cap OR all of the 6 year old plug wires are bad. I also tried to get #1 to fire with a spare plug and it wouldn't. So that would be #1 and #2 not firing.

I don't know if they are copper core wires or not but why in the world would I lose all spark at once?

I also tried a spare cap/rotor(new) that he sent along with no change.

Everything is tight, wires on cap are snapped tight, cap is tight on distributor. What gives? Wires?

Can I put a meter on them cap plugs where the wires come out and check that to isolate the wires?

award.........I flunked mind reading, just ask my ex-wife of 32yrs. There are 2-types of distributors used for the 8N engine. 4-nipple squarecan coil ...and... 5-nipple roundcan coil. Unlike the squarecan coil, the roundcan coil is bulletproof. You can count nipples, can't you?

You ask......."I don't know if they are copper core wires or not but why in the world would I lose all spark at once?"........Iff'n in doubt, buy another set of real copper-core sparkie wire and cut to fit. ($15, cheap) Modern cotton-string sparkie wires cause WEAK sparkies on 60yo tractors.

Yes, you can putta meter between the ends of yer "un-known" sparkie wires and measure resistance. Good copper-core about 1-ohm; BAD string sparkie wires about 10,000-ohms resistance. Simple, eh? ........Dell, the retired electronic calibration engineer

" They checked them and compared to known good ones they had (distributors). Mine checked good (same minor movement as their spares). "

Huh? Don't they own a mic? I've got the specs, but w/o a mic, it won't do you or them any good.

But that's not your problem anyway.

Assuming that the bushings & advance weights are ok, & that you have correct voltage to the coil, the most common electrical failure (no spark, weak spark) points on the frontmount are:

1. The insulator under the brass concave head screw & where the copper strip attaches. (it’s fiber & will wear out; poke & prod w/ your meter leads to make sure it still works)

2. The pigtail at the bottom of the coil not making contact w/ the concave head brass screw inside the distributor. (With the coil on, the pigtail must firmly contact the brass screw. No contact = no spark.).

3. The copper strip is broken or grounded to the plate. (look very carefully for cracks & breaks)

4. The condenser wire grounding to the plate or side of the distributor.

5. The tab on the bottom of the coil not making contact w/ the brass button on the cap. (With the cap on, the tab must firmly contact the brass button. No contact = no spark.)

6. Incorrect positioning of the spring clip on the plate causing the pigtail to ground. (the open part of the clip goes between 7 & 9 o’clock on the plate. That puts the straight part of the clip opposite of the timing screw at 3 o’clock)

7. Incorrect seating of the coil on the distributor due to a loose bail or no gasket.(the coil must not move at all; if it does, replace the gasket or bail. Or stick some cardboard under the bail).

8. Water/moisture inside the cap due to gasket failure or the absence of a gasket. (the cap AND coil have gaskets)

9. Dirty/corroded/burned/incorrectly gapped or misaligned points.

10. Burned rotor, cracked/carbon tracked cap.

You can disregard items 1,2,6 & 7......but you somehow connected that roundcoil somewhere, so you need to check that connection carefully.


First, make sure your meter/light works (don't ask....)

Inspect the points; if they are pitted or burned, replace them. Next, 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. Make sure the points align correctly. Proper alignment is also critical to longevity. Look at the points when they are closed; both sides should mate evenly. Then, check the gap at .015 on the high point of all 4 cam lobes.

Now, follow these steps:

1. Coil off, cap off, points open. One probe on the brass screw & the other on both sides of the open points. On the side closest to the cam, you should have continuity. Not on the other side! If you do, you will also have continuity everywhere because the points are grounded.

2. Coil off, cap off, points open. One probe on the brass screw & the other anywhere on the body of the distributor. You should have no continuity! Now, rotate the tang on the distributor....as the points open & close, you have continuity (closed) and lose it when they open.

3. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other on the cam side of the open points. You should have continuity!

4. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other anywhere on the body of the distributor. You should have no continuity!

At this point, I just put the distributor, coil & cap all back on the tractor as a unit. The reason I do this is because it is real easy to get the cap or coil mis-aligned trying to put it back together one piece at a time & the result is something gets broken or you get a ‘no spark’ problem.

It's possible to put it back on wrong & break it. Look at the slot on the end of the cam shaft. What ever angle it happens to be, turn the distributor tang to match it. Make sure you can tell the wide side from the narrow side on both the cam & distributor! (close counts) Then place the distributor on the front of the engine, gently push it in place & slowly turn the distributor body until you feel the tang slip into the slot. Rotate the distributor body until the bolt holes line up. Then, hand tighten the two bolts until the distributor body is flush w/ the timing gear cover.

Finally, double check your firing order & plug wires. It’s 1-2-4-3, counterclockwise. It’s very easy to cross 3 & 4.

Post back w/ results & any other questions.
75 Tips

Front mount square can coil. Battery voltage at coil top. Light cycles bright/dim with engine cranked. Coil pig tail IS making contact to distributor brass screw. Points are barely even used and set correctly. Plug wires are NOT crossed.

I'm off to see if the neighbors meter can test spark plug voltage (coming right out of the FOUR nipped cap. I am even take a 14 ga. house wire to test a plug. I'll check back in a little while with results. BTW, I'm in the country and have to chase down copper wires in town.

Ok, I took a copper house wire and put it in the cap and wrapped the other end around a plug head and grounded on head. Nice arching white spark. I'm off to find some copper spark plug wires.
Thanks guys!

ok so I got to town and got "tin coated copper wires" as that was all they had. $21.00.

Got home and replaced each plug wire. Tried to start it and she just grumbled until the soaked plugs could get cleaned out.

She runs so good now. Don't know for certain if resistor type wires wear out, somehow, over time on these machines but I was glad to get it going again. Even had some time to drag the garden a little bit. Thanks all!

I had a troublesome ignition on a front mount distributor a couple of weeks ago. Did everything over and over to try to fix. It had copper metal wires but very old and tied together tight with plastic wire ties.
As a last resort I installed new metal cored wires and didn't tie them tight together. Started and ran perfectly with any of the sputtering and spitting as before. I think the spark was migrating between the wires because of broken down insulation.

I was taught about this condition at an International Truck school I went to in the late 60s and it finally paid off.

Zane

(quoted from post at 20:20:31 07/22/13) ok so I got to town and got "tin coated copper wires" as that was all they had. $21.00.

Got home and replaced each plug wire. Tried to start it and she just grumbled until the soaked plugs could get cleaned out.

She runs so good now. Don't know for certain if resistor type wires wear out, somehow, over time on these machines but I was glad to get it going again. Even had some time to drag the garden a little bit. Thanks all!

Click to expand...

Glad you got it going! Now with that piece of copper wire you
have another tool to put in your "mental tool box" for future use!

You may have gas fouled spark plugs.New wires wont help.

ya, wires will get you a lot of times.
test perfect, look perfect, but will arc to something
they are not supposed to under the 'lightning's' energy.
First thing I look for if a tractor starts to miss, even on bright days, you can see it, or hear it.
working on one now with nice soldered ends, solid core, still supple silicone wires......that will arc to anything close...
shame, they are nice
til I can pick up a set, I have them tied every which way
to keep them in the clear.
(BTW, NAPA has a decent set of solid core roll your own
7mm silicone wires cheap made for 4cyl cars, that work well.
so long, that after you cut them for a tractor, lots left over for the next round coil conversion)

I had a new set of wires from dealer to put on my Toyota Celica 30 years ago that looked like a Christmas tree under the hood. "They ohm out right" they said and wouldn't replace them. FWIW.