Cannot get spark on 2n

We've inherited a 1946 2n and we are new to tractors. We have re-wired the tractor and have also bought a new starter, new coil , new distributor, new spark plug wires, and new spark plugs.

We verified the gap width between the points of the new distributor (measured when it is wide open) to be 0.015 inches. It was snug at 0.015 inches with a good drag when inserting the feeler gauge.

We also verified that the timing of the distributor was correct by inscribing a mark 1/4 inch from one of the holes of the distributor as shown in the shop manual. By using the straight edges we verified that the points became open at this mark (we used an ohm-meter to verify this as shown in a youtube video we found).

So I made absolutely no changes to the new distributor - it seemed to be correct.

I then replaced the coil, the distributor, the spark plug wires and the spark plugs.

I verified the continuity of the spark plug wires with an ohm meter.

My battery voltage was 6.27 Volts, I turned on the key, and I measured 5.58 Volts at the coil - is this because of the resistor block?

I then cranked the new starter, but no spark!

Here is how I am testing for spark:

I disconnect one of the spark plug wires, and insert a good spark plug in it. I lay the spark plug on the engine block, and I make sure it is grounded by clipping the spark plug to ground using an alligator clip. I also used a volt meter to verify that the spark plug is grounded.

I cranked the starter and still no spark at the spark plug!

I bought 2 different inline spark plug testers - one was a Briggs & Stratton, the other one came from AutoZone. I clamped one end of the spark plug tester to an actual spark plug inserted in the engine while the other end was inserted into the spark plug wire.

Still no spark when cranking the starter!

I have a circuit tester consisting of a light that lights up when voltage is applied to it. I tried inserting the light at the point where the spark plug wires are inserted into the distributor right at the metal contacts.

There was no light from the distributor when I was cranking the starter. Should I see the light flicker from the distributor when I am cranking the starter?

Is there a way to bench test the coil, the distributor, the spark plug wires and spark plug all together when off the tractor? Is there a way to bench test that my distributor is actually firing properly and some voltages?

What am I doing wrong? Any help would be greatly appreciated!

"Is there a way to bench test the coil, the distributor, the spark plug wires and spark plug all together when off the tractor?"

Sounds like you've done your homework.
There is a way to test all of that together on the bench.
It's quite a setup though.
Easier to test the distributor and coil together on the bench.
Measure continuity from the top post of the coil to the casing
of the distributor. Should have continuity with point closed and
an open circuit when they are open.

Did you clean the shipping oil/corrosion off the new points?
Maybe they're just not closing, although your voltage reading
seems to indicate they are at least partially closing.
You should have battery voltage at the top of the coil with points
open and roughly half that when the points are closed.

Assuming that the bushings & advance weights are ok (*see below), & that you have correct voltage to the coil (battery voltage with the points open and about half that with the points closed), the problem is in the distributor.

Once you get the distributor on the bench, the first thing you need to check is bushing wear. If the shaft has any sideways movement AT ALL, the bushings must be replaced.

The most common electrical failure (no spark, weak spark) points on the front mount 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) If you need to replace the insulator, use a .250 x 3/8 nylon square nylon anchor nut available at most big box home stores

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. I use only Wells, Blue Streak or Echlin brand points (* *see below). If you are using quality points and cannot get the gap to open to .015, chances are you need to replace the bushings.

10. Burned rotor, cracked/carbon tracked cap.

After you find the problem & re-check the point gap, do a continuity check before you put the distributor back on the tractor. Before you start, make sure your meter/light works.

With the distributor still off the tractor, 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. Put the coil on the distributor, 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 misaligned 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. Whatever 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). 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. Hand tighten the two bolts until the distributor body is flush with the timing gear cover.


* Unscrew the plate hold down screw & remove the C clip to get the plate out. Remove the shaft & weights. The weights should freely move.


* *NAPA part numbers:

? Points: FD-6769X
? Condenser: FD-71
? Rotor: FD-104
? Cap: FD-126
75 Tips

make sure the coil is well seated to the distribuitor.

put a test lamp inline with the coil and roll the engine over with the key on.. lamp in test light should blink...

if it never comes on.. points are not closing or are glazed.. if it stays on, points are shorted.

post back.