I have a ford 8N tractor with a front mount distributor I am having issues with! I am borrowing it from a friend and he doesn't have time to help me figure out what the deal is with it! I don't know hardly anything bout tractors but whats going on is when I first got the tractor it ran good for about 20 min after I got it to my house then all the sudden it started surging and dying then after a little bit it would run for about 5 seconds then die! When it died it sounded like someone just cut the power to it???? Now I can't even get it to fire now no spark!!! I have pulled all plugs and cleaned and gapped, pulled distributor and replaced contact points and condenser! Cap looks good I checked for voltage to and out and I'm getting 12 v to and out of dist., but still no spark! This is supposedly a 12 volt system! Checked plug wire and they all seem to be good! Hooked meter up to coil wire and cranked over to see if voltage is dropping out when turning over and that checked out good! Took dist to guy and he set contact point gap with feeler gauge and meter! Looked at ceramic resistor to see if it was cracked! It looks ok I'm getting voltage in and out on it I did notice that coil wire in back looked good but what ever runs through coil wire in resistor was split in two! Not sure what it supposed to look like but I'm gettin a reading in and out so assumed it was fine!! One other note I want to add is right after this started happening I did find coil wire had got pulled in to center pulley due to slack in wire and it had been split in two from pulley! Not sure if its timing issues or even I you can time a front mount dist! But just don't know why all the sudden it went from doing good to nothing at all???? Please help!!!
- Thread starter Derek74
- Start date
Bruce (VA)
Well-known Member
Before you check anything else, make sure you have the correct voltage at the top of the coil. It should be battery voltage w/ the points open & about half that w/ the points closed.
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.
Unless the coil is cracked or shows a dead short, chances are it's fine; square coils rarely fail cold. Pull the distributor & do a continuity check.
First, make sure your meter/light works (don't ask....)
You can change points everyday & it will not fix bad bushings. If you are having trouble w/ points failure, check the shaft. If you detect movement, chances are it needs new bushings.
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
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.
Unless the coil is cracked or shows a dead short, chances are it's fine; square coils rarely fail cold. Pull the distributor & do a continuity check.
First, make sure your meter/light works (don't ask....)
You can change points everyday & it will not fix bad bushings. If you are having trouble w/ points failure, check the shaft. If you detect movement, chances are it needs new bushings.
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
Jim in Eastern North Caro
Member
If it ran OK before the stumbling problem, it is probably not timing; so hold off changing that for now. You describe symptoms of fuel starvation, so check screens in the filter below the tank, and in the inlet tube fitting to the carb. Flush with fresh gas and give it another try. Go with simple things first.
Jim in Eastern North Caro
Member
Sorry..., I read through the "no spark" comments. So go with Bruce's remedy, he'll get it for you.
Ok so after going through your checklist everything seems to be good!!! I did have dist off and coil attached and grounded it to see if I can see spark on contacts in dist and I dd see some but when I did it was petty weak!! I talked to the guy tht owns the tractor and he just now remembered that this same thing happened to him a while back and everything checked out good EVEN the COIL and he said he replaced the coil and after that everything worked good, so guess I'm gonna replace coil and see if that does the trick!! I just have never heard of a coil reading and looking like its good and be bad or weak! I've always heard a coil is either good or dead!!! What do you think??? Any other suggestions??
Ok so my dad went on a head and bought a new 12v square top coil and a new resister the ceramic one and the repair place gave us a wiring diagram of how a 12v system is supposed to be wired and found what is supposed to be another resister I think right behind where the ignition switch and voltmeter is was not wired no wires running to it at all!! Don't know if this is a big deal and need to go get a new one or what! Figured it ran before without it it will run again! Anyway we put on the new coil and the new ceramic resister and I seem to have fire now it will start for a second or two and that's all!! Don't know if its a timing issue now or what! Not even sure if you can adjust or know how to adjust! Also just curious if anyone might now the specs and instructions on correct way to adjust contact points?? Also do they have a 2 diff condensers one for 6v and a diff for 12v and if that might have a play in why it won't start fully cause I bought a new one and if there is two I may have bought the 6v condenser! Any help would be awesome!! Thanks in advance! I'm just glad I'm getting fire now just need it to start and stay started!
With a front mount distributor, you should use the original ballast resistor on
the back side of the dash board. Wire wound.
If you have a 6V coil on a 12V conversion, you would need the ceramic one too.
If you have a 12V coil, you only need the ballast resistor. The ceramic one
isn't the same as the ballast resistor.
You've changed parts, which may have helped or hurt, but now that you have
different symptoms, go back and follow the steps Bruce posted for you again.
They should get you to the right point.
You're close, just slow down and do some troubleshooting. It will run.
the back side of the dash board. Wire wound.
If you have a 6V coil on a 12V conversion, you would need the ceramic one too.
If you have a 12V coil, you only need the ballast resistor. The ceramic one
isn't the same as the ballast resistor.
You've changed parts, which may have helped or hurt, but now that you have
different symptoms, go back and follow the steps Bruce posted for you again.
They should get you to the right point.
You're close, just slow down and do some troubleshooting. It will run.
I never changed part just replaced with new one! I guess the
ballist resistor on back of dash was never used I'm assuming
cause when I found out there was a resistor back there I
looked and there wasn't anything attached and I check for
continuity and I got nothing so I think it's bad! The ceramic
resistor was the only resistor used and we replaced it with a
new one assuming a 12v one if there is diff ones! The old coil
was a 12v and we bought a new 12v to replace it! We replaced
the contact points and the guy that owns the tractor
supposedly set the points when I took it to him and since we
have pretty much done everything and we are finally getting
fire but just won't start it will hit once maybe twice I'm thinking
that he may have set points wrong but I don't know how or
what they are supposed to be set at! We are thinking its either
the points are set wrong or I'm having gas issues getting to
engine! I know since the ballist resistor wasn't connected to
begin with and has ran before it should run again just need to
figure out what's going on now! Just thinking it could be points
but need to know what to set at! If you have any other ideas let
me know!
ballist resistor on back of dash was never used I'm assuming
cause when I found out there was a resistor back there I
looked and there wasn't anything attached and I check for
continuity and I got nothing so I think it's bad! The ceramic
resistor was the only resistor used and we replaced it with a
new one assuming a 12v one if there is diff ones! The old coil
was a 12v and we bought a new 12v to replace it! We replaced
the contact points and the guy that owns the tractor
supposedly set the points when I took it to him and since we
have pretty much done everything and we are finally getting
fire but just won't start it will hit once maybe twice I'm thinking
that he may have set points wrong but I don't know how or
what they are supposed to be set at! We are thinking its either
the points are set wrong or I'm having gas issues getting to
engine! I know since the ballist resistor wasn't connected to
begin with and has ran before it should run again just need to
figure out what's going on now! Just thinking it could be points
but need to know what to set at! If you have any other ideas let
me know!
"I never changed part just replaced with new one!"
Isn't that "changing"?
"I guess the ballist resistor on back of dash was never used I'm assuming"
An incorrect assumption. Ford put it there. It was used. It may be bad.
"The ceramic resistor was the only resistor used and we replaced it with a
new one assuming"
There's that word again. The fact that it was wired wrong when you got it
may be part of the problem. Although I doubt that's is all of it.
"I'm thinking that he may have set points wrong but I don't know how or
what they are supposed to be set at! We are thinking its either
the points are set wrong or I'm having gas issues getting to
engine!"
That's a lot of thinking, but not much troubleshooting.
"I know since the ballist resistor wasn't connected to begin with"
Again, it was connected, someone disconnected it and wired it incorrectly.
It may run that way, but no guarantee on how well or how long.
"Just thinking it could be points but need to know what to set at!"
They should be set at .015 per the I&T FO-4 manual. Do you have one?
If you're thinking it may be a fuel issue, and it may be, pull the plug out of
the bottom of the carb and see if gas will flow out of there in a steady
stream. Let it flow for a minute or two into a container. It shouldn't dribble
out, it should flow out fairly steady without interruption. Check what you
catch for dirt or water.
Make sure you have at least 3 gallons of fresh fuel in the tank.
There are three screens. One in the tank, one at the top of the glass sediment
bowl and one in the elbow going into the side of the carb.
You can check and clean the last two pretty easily.
We still don't know what the issue is though. Have you checked the quality
of the spark you're now getting? Is it a blue/white color or orange?
If you hold a spark plug wire close to the block, will that spark jump a 1/4 inch?
If you've been cranking on it a lot, it has probably fouled the plugs. I would
pull them out and dry them off with a propane torch, or, if you have a spare
set, swap them.
If you have taken the spark plug wires off the distributor, double check the firing order.
1-2-4-3 CCW. #1 at the front of the engine.
This is off the top of my head, and its late, so I still recommend you follow
the steps Bruce gave you below. I'm just adding a couple ideas.
Isn't that "changing"?
"I guess the ballist resistor on back of dash was never used I'm assuming"
An incorrect assumption. Ford put it there. It was used. It may be bad.
"The ceramic resistor was the only resistor used and we replaced it with a
new one assuming"
There's that word again. The fact that it was wired wrong when you got it
may be part of the problem. Although I doubt that's is all of it.
"I'm thinking that he may have set points wrong but I don't know how or
what they are supposed to be set at! We are thinking its either
the points are set wrong or I'm having gas issues getting to
engine!"
That's a lot of thinking, but not much troubleshooting.
"I know since the ballist resistor wasn't connected to begin with"
Again, it was connected, someone disconnected it and wired it incorrectly.
It may run that way, but no guarantee on how well or how long.
"Just thinking it could be points but need to know what to set at!"
They should be set at .015 per the I&T FO-4 manual. Do you have one?
If you're thinking it may be a fuel issue, and it may be, pull the plug out of
the bottom of the carb and see if gas will flow out of there in a steady
stream. Let it flow for a minute or two into a container. It shouldn't dribble
out, it should flow out fairly steady without interruption. Check what you
catch for dirt or water.
Make sure you have at least 3 gallons of fresh fuel in the tank.
There are three screens. One in the tank, one at the top of the glass sediment
bowl and one in the elbow going into the side of the carb.
You can check and clean the last two pretty easily.
We still don't know what the issue is though. Have you checked the quality
of the spark you're now getting? Is it a blue/white color or orange?
If you hold a spark plug wire close to the block, will that spark jump a 1/4 inch?
If you've been cranking on it a lot, it has probably fouled the plugs. I would
pull them out and dry them off with a propane torch, or, if you have a spare
set, swap them.
If you have taken the spark plug wires off the distributor, double check the firing order.
1-2-4-3 CCW. #1 at the front of the engine.
This is off the top of my head, and its late, so I still recommend you follow
the steps Bruce gave you below. I'm just adding a couple ideas.
Ok.... So I started to mess with tractor after work today and through some testing I found that we were in deed fouling out the plugs! I cleaned plugs and reinstalled and no better! Them found that plugs were bad! One plug had nothing and two were pretty weak and one was still pretty good so tested good plug on all the other wire to see if it was in fact plug or wires and the one gave a good spark on all 4 wires, so I changed out plugs and yes it finally started! Now only if I can figure out how to make it run stronger! Just gotta figure out if its flooding or starving it! I did take plug out of bottom of carb and fuel does come out pretty good! I have a feeling the carb probably needs a good cleaning or rebuilt!! I also still need to wire in the ballist resister it's only running with the ceramic one who know maybe that will help! Anyway looks like I'm making headway!!
Glad to hear you're making progress!
We recommend Autolite 437 spark plugs gapped at .025.
Do the spark quality test though, just hold the end of each plug wire about
a quarter inch from a good ground and have someone roll it over, key on.
(use an insulated tool or you'll know for sure if it has good spark!)
Spark shouldn't be yellow/orange, it should be blue/white and jump that gap.
If not, then that resistor "may" be the problem. Can't say for sure yet that it is.
As a temporary test, you could jumper a wire around it, but don't run it that way.
To check for flooding or starving, pull the choke out a bit while its running
and see if that helps or hurts.
If it hurts, it may be too rich.
If it helps, it may be starving for fuel but it also may be a weak spark problem.
Let us know what you find.
We recommend Autolite 437 spark plugs gapped at .025.
Do the spark quality test though, just hold the end of each plug wire about
a quarter inch from a good ground and have someone roll it over, key on.
(use an insulated tool or you'll know for sure if it has good spark!)
Spark shouldn't be yellow/orange, it should be blue/white and jump that gap.
If not, then that resistor "may" be the problem. Can't say for sure yet that it is.
As a temporary test, you could jumper a wire around it, but don't run it that way.
To check for flooding or starving, pull the choke out a bit while its running
and see if that helps or hurts.
If it hurts, it may be too rich.
If it helps, it may be starving for fuel but it also may be a weak spark problem.
Let us know what you find.
The spark plugs we bought we bought from O'Rieleys and the only had the NGK OR NKG well something like that! Spark looked good to me last night! I'm probably gonna end up taking carb apart and clean it! We found that fuel line to carb seemed to be clogged a week ago when we first started having issues with it then I noticed that there was no screen on 90 deg fitting going into carb so thinkin it may have gotten trash built up inside! I do have another question if some one could educate me on how the throttle works cause i noticed some rod runs to an area towards the carb but closer to the front! Just curious what all that is?? Looks like it runs to it then back to carb?? Also I have a wiring diagram for a 12v conversion I got from a parts and repair place and says that I need to run both the ballist and the ceramic resistor it says its for a 9N and 2N but someone told me that I just need to run to the original ballist resistor on back of dash board! Which is correct! This IS a 8N 12v system I'm working on! THANKS IN ADVANCE!!!
That thing up front is called the GOVERNOR. Throttle control runs to the governor, then from the governor to the butterfly on the carb. Governors compensate for load on the engine so you are not constantly moving the little lever on the dash when you go up a hill or pull something heavy.
As JC said, that linkage runs to your governor, then back to the carb.
As for the wiring, the diagram isn't much different from 9N/2N and early 8N.
They all used the front mount square coil.
That's where the confusion with the resistors comes in.
The best way to know for sure is to measure the resistance of the coil and resistors.
What you're shooting for is about 3.5~4 amps of current when running.
7.5 volts on a running(charging) 6V battery/(1 ohm 6v coil+1 ohm ballast resistor) = 7.5/2 = 3.75 amps.
If you put a 12 volt battery in there (~14V charging) and left the 6 volt coil,
you would have ~7 amps of current and would melt your coil.
That's why you add the ceramic resistor, to reduce the current with a 6V coil.
But you said you used a 12 volt coil.
If you went to a 12 volt coil, the internal resistance is higher than the 1 ohm
6 volt coil, so the extra resistor is not needed, but the ballast resistor is.
The ballast resistor, when cold, has almost NO resistance so you
get a boost to help start the tractor when cranking.
As it warms up, the resistance goes up and limits the current to the proper level.
That's the difference between using the original ballast resistor and the ceramic one.
Hope that helps!
As for the wiring, the diagram isn't much different from 9N/2N and early 8N.
They all used the front mount square coil.
That's where the confusion with the resistors comes in.
The best way to know for sure is to measure the resistance of the coil and resistors.
What you're shooting for is about 3.5~4 amps of current when running.
7.5 volts on a running(charging) 6V battery/(1 ohm 6v coil+1 ohm ballast resistor) = 7.5/2 = 3.75 amps.
If you put a 12 volt battery in there (~14V charging) and left the 6 volt coil,
you would have ~7 amps of current and would melt your coil.
That's why you add the ceramic resistor, to reduce the current with a 6V coil.
But you said you used a 12 volt coil.
If you went to a 12 volt coil, the internal resistance is higher than the 1 ohm
6 volt coil, so the extra resistor is not needed, but the ballast resistor is.
The ballast resistor, when cold, has almost NO resistance so you
get a boost to help start the tractor when cranking.
As it warms up, the resistance goes up and limits the current to the proper level.
That's the difference between using the original ballast resistor and the ceramic one.
Hope that helps!
Well finally this tractor runs again!!!! Figured first thing I would do hater I finally got it to start as stated in my last post when It had no power I would rebuild carb, so I did, and what would you know that did the trick!! This thing runs better now than it did before! I found dirt, carbon buil up and rust in carb! Now only thing I want to know now is that I had gotten a wiring diagram showing how to convert to a 12v (which it has already been converted, just makin sure it was wired right since the coil got Burt up) and on the diagram it shows both the ceramic resistor and ballisti resistor to be wire but in an earlier reply by someone on here said just the ballist! I just wanna make sure I do it right and that on diagram it says for 2N and 9N! Thanks in advance!!!'
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