No spark

[Caroline Chamblin]

1941 9N front mount tractor was running and
gets hot, loses power and I stop and cool
off and continue mowing. Got in the habit
of mowing for an hour and just heading back
to the barn. Wouldn't restart one day (I
keep the battery on a trickle charger and
not connected when not in use)
Fast forward battery not holding a charge
(old) and got a new battery, started right
up.
Fuel fine based on the 30 second drain test
out bottom of carb.

Went through testing procedure as detailed
by Bruce in VA. My ammeter hasn't worked
for years, bought a new one since a
working ammeter is necessary for
troubleshooting etc ammeter doesn't budge.
At all. New condenser, new coil, new
ignition - key switch. 6.65 volts on
battery and got the working results from th
At testing locations along the system.
Am stumped now. Ideas?

 

[Bruce (VA)]

See tip # 13.

As soon as it stops running, not 5 minutes later, check for fuel and spark.

Does the spark jump 1/4 in open air?

Remove the drain plug in the carb. Will the fuel flow fill a pint jar in less than 2 minutes?
75 Tips

 

[Caroline Chamblin]

Not running currently. No spark at plugs. Bench test of old coil is weak yellow spark. Put new coil in (not bench tested yet) no start.

I will check with pint jar tomorrow.

 

[Jim L WA]

It sounds like it started up and ran with the new battery. Now won't start after replacing ignition parts, (ammeter has nothing to do with starting). I would put the old condenser back in, make sure the new points don't have some coating on the contacts and try it again.
As for the ammeter not showing anything, you might have a bad cutout relay or generator.
Let's get it started and running first, then trouble shoot the charging system.

 

[Caroline Chamblin]

Thanks Jim. As I age it's harder to
remember the order I put things in, but I
think it started with new battery, then
quit. Towed out of field, wouldn't start.
Fuel was good so we measured voltage as
testing suggested. Got results that
suggested voltage to coil ok. But no spark
at plugs. When we bench tested the coil
distributor cap off, rotating shaft, we get
spark as points open and close. Anyway, I
will retest fuel again and do as suggested.
I appreciate the feedback.

 

[Caroline Chamblin]

Fuel jar photo after 1 min 2 sec

 

[Bruce (VA)]

The first thing you need to check is for battery voltage at the coil. Yes, you need a meter for that, not a light. With the key on, you should see battery voltage ( 6.35 v) with the points open and about half that with the points closed. If you do not see either, the problem is between the battery and the coil, e.g., the resistor, ignition switch or a bad connection.

Assuming that the bushings & advance weights are ok (*see below), & that you have correct voltage to the coil , the most common reasons for no spark or a weak spark on the front distributor are below. Check each one carefully. Even if you find a problem, check all 10:

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) Check for continuity between the top of the coil and the pig tail; a 6 volt coil will be around 1 ohm & a 12 volt coil should be 2 to 3 ohms.

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

4. The distributor is not grounded to the block because of paint or grease acting as an insulator. Or the points plate is covered in oil.

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.) Check for continuity between the top of the coil and the tab; you should see about 6k ohms.

6. A grounding issue inside the distributor: 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) or the condenser wire is grounding to the plate or side of the distributor.

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. If the shaft has any sideways movement AT ALL, the bushings must be replaced. (*** see below) If the tractor has been sitting unused for a few months, its highly likely that the points are glazed. Dress them with brown paper or card stock. Do NOT use a file or sandpaper. That removes the thin metallic coating on the surface and reduces point life considerably. With the points closed, you should have continuity between them; high resistance means they are glazed.

10. Burned rotor, cracked/carbon tracked cap. Brass dust in the cap is a sure sign of bushing wear.


After 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. The tracks should not be wallowed out.

** NAPA part numbers:

. Points: FD-6769X or ECH CS35

. Condenser: FD-71 or ECH FA200

. Rotor: FD-104 or ECH FA 300

. Cap: FD-126 or ECH FA 350



** Distributor cam lube NAPA:

https://www.napaonline.com/en/p/ECHML1

*** There are three ways to replace the bushings in a front distributor:

1. Buy new bushings (part numbers 9N12120 front & 18-12132 rear). Press out the old ones, press in the new ones and ream to fit. CAUTION: do not try this unless you have a press & know how to use it. If you break the base, a new one costs $130. If you bend the tower which holds the front bushing, a new plate will cost you $30. Resist the temptation to buy a new plate; most are pot metal and the threads will wallow out about the third time you change the points.

2. Take the new bushings and distributor to your local machine shop.

3. Send the distributor out for bushing replacement if you do not have a local machine shop
75 Tips

 

[lastcowboy32]

If you suspect a distributor problem, you could try to re-engineer an 80 year old distributor design in your mind, in order to troubleshoot it... and drive a few times to your local shop.

and then find out that it was actually carbon tracking or oil in the distributor

or maybe you bought a condenser, and it was a cheap on that was no good from the get-go

or maybe you bought new points, and then fiddled with them to set the gap.

OR... if time is money to you, you could commit the sacrelig of just getting the whole assembly, yes, from China... which is where everybody is getting their parts from anyway.

It will come with all new internals, no oil from years of usage, no carbon tracking, and the point gap set.

I bought one of these, and my little 2N, at 80 years old is now the best starting/running tractor on the farm again... and we have a 2018 Mahindra and 2009 New Holland.

At some point, I asked myself if troubleshooting components on my tractor was my hobby... or if I just want to get my 2N back to work as quickly, efficiently and cheaply as possible.

We have a working farm and I have a job..., I can't afford another hobby.

 

[Caroline Chamblin]

Glad that worked for you. It's an option, heard a lot of stories about quality control on
old tractor parts.

 

[Jim L WA]

(quoted from post at 10:42:58 06/20/23) Thanks Jim. As I age it's harder to
remember the order I put things in, but I
think it started with new battery, then
quit. Towed out of field, wouldn't start.
Fuel was good so we measured voltage as
testing suggested. Got results that
suggested voltage to coil ok. But no spark
at plugs. When we bench tested the coil
distributor cap off, rotating shaft, we get
spark as points open and close. Anyway, I
will retest fuel again and do as suggested.
I appreciate the feedback.

Okay, so you got a good fuel flow test. Did you try putting the old condenser back in? The spark you see across the points during your bench test doesn't mean the condenser is good. Part of the condenser's job is to keep that spark at a minimum to protect the point contacts.

 

[Caroline Chamblin]

I had to stop because of a planned project that involves rented equipment. 0should be
back at it next week.

 

[lastcowboy32]

I completely understand the reluctance to buy new parts from overseas. I want to counter with a couple of arguments:

1. You may be keeping your old distributor housing, but there is a very good chance that any parts you put into it are from overseas. I've been an electronics design engineer for years (30-ish)...and I've watched as the percentage of electronic components made in the US vs China went from maybe 50/50 to 99/1. Your new condenser? Good chance it's from China. And yes, I've watched my brother rebuild a distributor on an old gas tractor (JD 1520) by putting a brand new condenser in it...no worky... brand new out of the box. Had to put his old condenser back in, until he could get a new one.

2. Your distributor housing, if original, is 80 years old. The little offset tangs that drive it on the back? They wear. The groove in the gear that drives it from inside the block? They wear.

After 80 years, there is a higher probability that the wear tolerances will stack up so that you can install your distributor 180 degrees out of phase. I actually did that when I rebuilt my 2N and had plenty of clearance to put the distributor on.... but I did it as an experiment. I put it on both ways, just to see if it was that worn. It was.

Far be it from me to discourage someone from wanting to learn about and work on their old equipment and keep it original.

I'm also well aware of "quality control" issues from overseas.

However, 80 year old equipment, even though it was once made to very good quality control standards... gets worn enough to be subpar, compared to new equipment from overseas.

 

[JMOR]

(quoted from post at 14:52:13 06/27/23)
I completely understand the reluctance to buy new parts from overseas. I want to counter with a couple of arguments:

1. You may be keeping your old distributor housing, but there is a very good chance that any parts you put into it are from overseas. I've been an electronics design engineer for years (30-ish)...and I've watched as the percentage of electronic components made in the US vs China went from maybe 50/50 to 99/1. Your new condenser? Good chance it's from China. And yes, I've watched my brother rebuild a distributor on an old gas tractor (JD 1520) by putting a brand new condenser in it...no worky... brand new out of the box. Had to put his old condenser back in, until he could get a new one.

2. Your distributor housing, if original, is 80 years old. The little offset tangs that drive it on the back? They wear. The groove in the gear that drives it from inside the block? They wear.

After 80 years, there is a higher probability that the wear tolerances will stack up so that you can install your distributor 180 degrees out of phase. I actually did that when I rebuilt my 2N and had plenty of clearance to put the distributor on.... but I did it as an experiment. I put it on both ways, just to see if it was that worn. It was.

Far be it from me to discourage someone from wanting to learn about and work on their old equipment and keep it original.

I'm also well aware of "quality control" issues from overseas.

However, 80 year old equipment, even though it was once made to very good quality control standards... gets worn enough to be subpar, compared to new equipment from overseas.

hy even suggest 180 out of phase when poster said mows for an hour before trouble?? :roll:

 

[lastcowboy32]

(quoted from post at 12:29:53 06/27/23)

(quoted from post at 14:52:13 06/27/23)
I completely understand the reluctance to buy new parts from overseas. I want to counter with a couple of arguments:

1. You may be keeping your old distributor housing, but there is a very good chance that any parts you put into it are from overseas. I've been an electronics design engineer for years (30-ish)...and I've watched as the percentage of electronic components made in the US vs China went from maybe 50/50 to 99/1. Your new condenser? Good chance it's from China. And yes, I've watched my brother rebuild a distributor on an old gas tractor (JD 1520) by putting a brand new condenser in it...no worky... brand new out of the box. Had to put his old condenser back in, until he could get a new one.

2. Your distributor housing, if original, is 80 years old. The little offset tangs that drive it on the back? They wear. The groove in the gear that drives it from inside the block? They wear.

After 80 years, there is a higher probability that the wear tolerances will stack up so that you can install your distributor 180 degrees out of phase. I actually did that when I rebuilt my 2N and had plenty of clearance to put the distributor on.... but I did it as an experiment. I put it on both ways, just to see if it was that worn. It was.

Far be it from me to discourage someone from wanting to learn about and work on their old equipment and keep it original.

I'm also well aware of "quality control" issues from overseas.

However, 80 year old equipment, even though it was once made to very good quality control standards... gets worn enough to be subpar, compared to new equipment from overseas.

hy even suggest 180 out of phase when poster said mows for an hour before trouble?? :roll:

I only suggest it, because every time you take your distributor off and re-install it, you have the chance to install 180 out of phase.

Looking at previous comments about rebuilding a distributor, there was mentions of needing a press, bushings, plates...

It's all time and $ $ $.

And in the end, if it's an 80 year old distributor, the tangs are possibly so worn on it that you can mess up the installation of the distributor that you just spent all that time and $ $ $ on fixing.

And, if the tangs are worn, it's going to have a little timing shimmy to boot.

If this problem can be solved by installing a new condenser or coil? Great.

If somebody wants to learn how to rebuild their distributor and has the time and $$$. Also great.

But... to do so would be for sentimental reasons, not quantifiable... which is also fine.

Having said all of that, my new distributor from China may puke next week. I'll keep y'all posted. But, it did get my tractor quickly back to the field after about an hour of work with no trips to a shop or parts store.

 

[lastcowboy32]

Before I put on the new distributor, my coping mechanism for making sure I didn't re-install the distributor 180 out of phase was that, if I was going to remove the distributor, I would pop the cap and write down where the rotor was pointing. Then I would re-install with the rotor pointing in that direction.

But... without doing that, my old distributor was definitely a risk for a re-install out of phase every time it was removed.

 

[lastcowboy32]

It's really all just a comment on the parts situation that we are in.

I fully realize that parts from overseas aren't as good as original.

But, it's what we have, and we still have to vet trusted sources (NAPA etc) for where their parts come from; because it isn't as simple as just going to NAPA and guaranteeing that you'll get an American made part made to high standards.

The low quality part trap has many layers.

Avoid buying a full distributor from China because of quality control.

Then rebuild your own distributor...but... how do you guarantee that all of the parts that you are rebuilding your distributor with are not from China? And...are the parts remaining on the distributor (i.e. the drive tangs) worn so much that they are now inferior to a new part made to lower quality control?

 

[Caroline Chamblin]

It started right up and ran for a bit less
than 1 hr with new battery. Died in the field
right in the middle ofowing. So suddenly I
didn't even have time to disengage the PTO and
try to make it back to the barn. I let it cool
off and changed nothing at that point. It
wouldn't start. Did fuel testing. Fuel was
good. Filled jar in less than 2 min. Last year
in summer 75 degree weather up here, ran for
an hour of mowing, lost power but I could just
disengage pto and go to the barn to let it
cool off and mow again a few hours later. This
was different. So the original no starting
after 1 hr running on new battery was with no
other changes. Thanks

 

[Mad Farmer]

(quoted from post at 23:15:27 07/03/23) It started right up and ran for a bit less
than 1 hr with new battery. Died in the field
right in the middle ofowing. So suddenly I
didn't even have time to disengage the PTO and
try to make it back to the barn. I let it cool
off and changed nothing at that point. It
wouldn't start. Did fuel testing. Fuel was
good. Filled jar in less than 2 min. Last year
in summer 75 degree weather up here, ran for
an hour of mowing, lost power but I could just
disengage pto and go to the barn to let it
cool off and mow again a few hours later. This
was different. So the original no starting
after 1 hr running on new battery was with no
other changes. Thanks

Problem sounds like mine I had when original coil was going bad. It got hot it died. Cooled down it ran again. Eventually it would not start and I was stuck in the field.

A Sunday evening and only place open that had a coil was TSC. I went there with hopes of getting a coil. When I opened the box it was a POS. The top/cover of the coil was loose so you could see a gap. I passed in that. Pigtail was ugly too.

Next day I ordered an Echlin coil from NAPA, cost 2X the TSC POS. But it was much better made including the pigtail.

Not sure where you got your replacement coil?

 

[Jim L WA]

Caroline, what Mad Farmer is saying could be right, but you might have an ignition switch that's going bad. You can prove that by running a jumper wire from negative battery to the ignition switch side of the ballast resister as soon as it quits again. If it starts right back up and runs then you have nailed it.

 

[Mad Farmer]

(quoted from post at 10:33:49 07/04/23) Caroline, what Mad Farmer is saying could be right, but you might have an ignition switch that's going bad. You can prove that by running a jumper wire from negative battery to the ignition switch side of the ballast resister as soon as it quits again. If it starts right back up and runs then you have nailed it.

I carry small and large gauge jumper wires w/alligator clips in my Ns toolbox.

Also a short large gauge, to jump around the genny cutout if it goes bad.