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No Spark on 9n

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M

Mark Maxfield

Member
Hello everyone, my first post and first ford tractor.
It is a 1940 9n I Bought it without hearing it run. I got it home and first cleaned the sediment bowl, then checked the filter in the elbow at the carb. Gas flows out the line that goes to the carb. I pulled a plug wire off and hooked a plug to it and laid it on the head and cranked it over. No Spark. So got the book out and pulled the coil and distributer adjusted the points and put it back together. Still no spark. Has newer wires points and plugs. Im getting 6vdc down at the big red wire on top of the coil with the key on. So now Im lost as how to trouble this. Any suggestions?
 
the proper 6v system needs a wire to the ignition switch, to a resistor on the dash, then on to the top of the coil. key on and points open you should see 6v. key on and poitns closed.. probably closer to 3v

points need to be gapepd at .015 on a front mount.. IE.. .015 breaker gao when the rubbing block is on the top of a distribuitor shaft lobe.

post back.

ps.. gas tot he carb is good.. gas thru the bottom of the carb bowl drain is even better.

soundguy
 
Mark.......congrats on yer new-to-you 9N. Also congrats on learning that the eazy way to change/adjust the points is by removing the 2-bolts and doing it on the kitchen table.

You write....."Im getting 6vdc down at the big red wire on top of the coil with the key on"......that tells me yer points are OPEN. Iff'n points are closed, you'd read about 3-volts. Try rolling the tractor in 2nd-gear (1-ft?) to move the engine abitt and see iff'n you gitt 3-volts.

Sometimes, neubies change points (0.015) and fergitt to "polish-off" the invisible anti-corrosion protection. Just clamp a $1-bill between the points and pull thru ...or... iff'n yer really cheap, torn strip of heavy brown paper grocery bag. .......Dell, yer self-appointed sparkie-meister
 
Thanks all for the quick help. I will try turning the engine over so the points close and check vdc. The points were not new I cleaned them up with file a bit so I dont think any of the new clear coat is on them. I do think the wire runs from the switch to a terminal with the resister on it then to the coil. thanks again. I thought it might be a bad condenser. And after more reading I found a post about checking the continuity of the points open and shut and will look into that.
 
most condensor failures are 'short' and if shorted that would act like closed points and you would not see the 6v.. so we know the condensor is not shorted. the other fialure mode is 'open'

that leads to burnt points very fast.. I think we can rule that out, as you would have weak spark immediatly at least.. not 'NO spark' like you are seeing.

post back.

soundguy
 
Mark if you filed the points and didn't run a piece of clean paper between them (dollar bill, groc bag, piece of puter paper) you could have created you own problem! I learned the paper trick (never heard of using a dollar bill till I got on this site) when I was a kid before the started making solid state ignition. I do know it works and just used puter paper on the points while getting my swather ready to cut hay.

Rick
 
Are you sure the spark plug had good contact wiht a clean,rust&paint free bolt or other area?You can make sure with a couple of clips,and a pc.of wire,just attatch one end to the plug threads,other to good gd.There are a lot of places in the dist. where you can get a short,get a meter and check for continuity through the dist. and you'll get it.---lha
 
There are ways to check for spark & fuel that work & ways that don't. For example, having gas to the carb is nice, but having it past the float is what counts! That’s why removing the bolt in the bottom of the carb is the way to do it. And, same thing w/ spark at the plugs. Some folks think that checking for spark means pulling a plug wire off & looking for one. Well, it's the distance the spark jumps at the plug that gives you the info you want. It takes about 17kv to jump a 3/16" gap & 22kv to jump ¼” in the open air, so that's why you need to use a spark plug. Or, a store bought plug checker. Remember, it’s 14psi outside of the engine & about 90psi at a 6:1 compression ratio in the cylinders & compressed air creates electrical resistance, so you really need the 17-22kv to fire the plugs when the engine is running.

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

1. The insulator under the brass concave head screw.

2. The insulator at the end of the points where the copper strip attaches.

3. The copper strip is broken or grounded to the plate.

4. The condenser wire grounding.

5. The pigtail/tab not making contact.

6. Incorrect positioning of the spring clip on the plate causing the pigtail to ground.

7. Incorrect seating of the coil on the distributor due to a loose bail or no gasket; the coil must not move at all.

8. Water/moisture inside the cap due to gasket failure or the absence of a gasket.

9. Dirty/corroded/incorrectly gapped points

10. Burned rotor, cracked/carbon tracked cap.

When I was 16 years old making $1.25 an hour & a set of points cost $1, I filed points. I must have been good at it because I recall it was almost a weekly exercise. If you ever file a set of points, you will remove the metallic coating on them & reduce the life span considerably. Unless you plan to keep on filing them, plan on replacing them pretty soon! Because you will need to pull the distributor anyway, go ahead & get a condenser & a set of points. Quality parts are critical to longevity. Having learned the hard way, I most always use Blue Streak brand points. They are made by Standard parts & available at many auto parts stores. (frontmount points also fit a 48 Ford as I recall) Beware of sticker shock: $16-18 a set. My next choices are Wells or Echlin. Look for a brown rubbing block. Unfortunately, many folks have experienced problems w/ points made by Tisco, Sparex, A&I Products and any TSC ignition parts.Even as tight as I am, I always change the condenser when I change the points…….and then I toss the condenser in the “used” parts box. A bad condenser is rare; you can tell if the points are pitted/burned w/ metal transfer.

Pull the distributor & replace the points & condenser. Then, do a continuity check.

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



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 (it’s easier to do this from the left side). 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.

Post back w/ results & any other questions.
50 Tips
 
One of the reasons for pulling the points out and fileing them was that I couldnt quite get 015 between them. Going to pull the assembly out after my coffee. thanks for all the insight and help.
personal stuff, I live in Michigan, 58 yrs old. Worked around machine almost all my life. Never changed a set of points till I was 20. Was in the service after school 70 till 72. Army. Work as a fix it man for a chain for 31 resturants covering almost all of Michigan. Have very little spare time. Have had a farmall c for 20 years and use it for everything. Reason I wanted a ford is Im tired of using junk implaments behind the c.
 
Ok had my first cup of coffee and went out and pulled the unit. Checked 1 thru 4 and all checked as it should in your message. Does that show that the coil is good and condenser is good? If so then what is the cap or rotor bad? I noticed that this cap really fits tight in the dist. really have to pry it loose. and I have mositure in it also. I know there is a gasket between the cap and body and a cork gasket between the coil and body/cap but the cap just does not fit down into the body as i think it should. I can see a bit of a line between them but I do not want to hammer the cap down into the body. I CANNOT see daylight between them and know there is a gasket there but should the cap fit down into the body farther? thanks
 
Still no spark, pulled the plugs and checked the condition of them. not great, I called the local car parts place and they have cap and stuff in stock they say. So going to pick up cap rotor and plugs. Get back later. thanks guys
 
Mark, you need a second cup of coffee. Go get it & then re-read the 10 likely causes of no-spark that I gave you. Read this one carefully:

" 8. Water/moisture inside the cap due to gasket failure or the absence of a gasket."

Now, compare that to what you just said:

" and I have mositure in it also. "

Follow me on this........you have a bad cap and/or gasket that lets moisture get in the cap. Moisture conducts electricity. You have no spark.

Get a new cap & gasket.

Keep reading. I also said another cause of no spark is: " 9. Dirty/corroded/incorrectly gapped points "

You said: " I couldnt quite get 015 between them. " Why do you suppose that is? It's because the wear block has worn down.

You asked " Checked 1 thru 4 and all checked as it should in your message. Does that show that the coil is good and condenser is good? " No, not at all. What you did was a continuity test. All that does is make sure you have continuity (a connection) between the parts and not to ground. Soundguy told you about condenser failure; all I can add to that is that it's rare.

Regarding the coil, there is a reason that coil failure isn't on my list of the top 10 no-spark causes.......because the other 10 reasons are far more common than a burned up coil.

Coil problems are difficult to diagnose. For starters, round coils are pretty robust & square coils aren’t (because of the difference in insulation used), but neither one will hold up to a poorly done 12v conversion that allows too much current to the coil or leaving the key on (see tip # 38). Too much current creates heat which melts the insulation. Insufficient resistance in a 12v conversion will do the same thing. Rarely do coils just “go bad.”

There are a few ways to see if a coil is bad, but it’s not possible to determine if a coil is good w/o some expensive testing equipment. If you detect a dead short or high resistance in the coil w/ an ohm meter, it’s bad. If it’s cracked, it’s bad. If a sidemount coil w/ battery voltage to the primary will not jump a ¼” gap from the secondary wire to the block, it’s bad. But, here is the hard part: even if you do not detect a short, even if it will produce a spark, even if it’s not cracked, that doesn’t mean the coil will work when it’s hot & under a load. So, it’s a process of elimination. If the tractor starts & runs fine for 30 minutes or an hour then cuts off & refuses to re-start, and you checked for spark at the plugs & it had no spark at all, AND you have the correct voltage at the coil that’s a good sign that you have a bad coil. Let it cool off, restart it & if you have a good spark, odds are it’s a bad coil. But, even then, you might end up w/ a spare coil on the shelf!

Bottom line.......coils do go bad, but I'll venture a guess that 75% of new N coils sold today are sold to folks who do not understand how to diagnose a poor spark problem or how a coil works. So, for those who don’t know any better, in a no spark situation the first suspect is usually the coil……and, more often than not, it isn’t the problem.
50 Tips
 
If you plan on keeping your 9N long term.I bought a Petronix kit # 1247XT for front mount distributor.I don't know what you have and you may want to be sure your 9N is worth spending this $$$ on.I Bought mine off e-bay cheaper than I could find it anywhere else.I looked too.It's worth it because my 8N runs in the rain with no problems now.Just a thought you may want to research on once you have it running.It is simple to do and you will spend less time wasted on points I promise.Cost of mine was 147.95 + 10.00 shipping.This kit is for negative ground system only and comes with everything you need. Jay
 
Installed all new parts but coil, still no spark, With key on I have 6.3 at top side of coil and rotated somewhat I get 4.7 vdc. Even replaced plugs as they looked bad. Checked wires and they are heavy wire inside of soft rubber.
Im thinking that its out of time. Going by my book FO-4 you can set the timing. The book talks about a 1/4 inch from the small hole. but it looks like it points to the bolt mounting hole to the block as being the small hole is that the hole to get the 1/4 inch at? If so mine is off. my serial number is 9N 35320. thanks for the help.
 
Mark......when you rotated the engine and now have 4.7vdc, that tells me that yer points are CORRODED or BURNED. Additional resistance in the circuit. Its the LAW, Kirchoffs Law. Resistors in series must always total the the applied volts. (6.3) You should loose about 3.2vdc thru yer infamous ballast resistor and therefore should have about 3.1-volts at the top of the coil 'stedda' 4.7vdc.

Do I haffta tell ya to replace yer BAD BURNED POINTS???

Yes, the FO-4 picture is correct for timing the weird 4-nipple frontmount distributor. ......Dell, yer sparkie-meister
 
All of my frontmount N's run just fine in the rain or snow; I didn't need to spend $157.95 to make it happen either. I spent $2 for the gasket kit.
DSC03063.jpg

50 Tips
 
Lets see..........I suggested (twice) that you have a points problem. Dell suggests it as well. Now you think it's the timing. Did you replace the points & set the gap correctly?

And, how is it you are "rotating" the coil? Check out my likely cause for no spark, # 7: " Incorrect seating of the coil on the distributor due to a loose bail or no gasket; the coil must not move at all."

Well, it's not the timing, but if you want to try, here's how to do it.

Get a meter or test light, a 21/64” drill bit & a metal straight edge. Put the distributor face down w/ the condenser on the left & the timing plate lock screw on the bottom. Look at the end of the shaft: it has a narrow side & a wide side. Make sure you can tell the difference. Now, place the drill bit in the bottom mounting hole. (this will be your reference point for measuring) . Next, place a straight edge on the wide side of the tang on shaft as shown in fig. FO83 in the I&T FO4 manual. Rotate the shaft CCW until the straight edge is ¼" away from the outside edge of the drill bit you stuck in the distributor mounting hole. At this distance, the distributor points should start to open. (get your meter/light out now & check) If not, loosen the timing plate lock screw and turn to advance or retard the timing. (move the plate down to advance timing, up to retard) Remember, each one of those little hash marks represents about 5* of timing. Keep adjusting until you get the proper ¼" setting. (if the plate won’t move, you might need to remove the big C clip to loosen it a bit) As you’re adjusting, eliminate backlash by turning the shaft backwards (CW) and bring the shaft forwards (CCW) to measure your setting. This ¼" setting will get you static timing at top dead center.
timing003.jpg

50 Tips
 
I pulled it again. bye the way there are new points in it. dont know why I have 4.7 instead of 3. Maybe they are open a bit to far. I read 17 was better. Have to try the 15. Dont think that is the cause. Anyway, pulled it again. Did a real cleaning to it with the shaft, timing plate removed and now I see the way its timed. the longated slot for the timing plate lock screw. Think I got it timed closer. If I did it to the proper hole. The book shows using one of the holes that the bolt goes through to the block. No one chimed in and said it was the wrong hole so I assume it was the right one. But still no spark.
 
Got new points in it. Thank you very much for you detailed description of the process and photo. I did it backwards of your description and the book shows rotating the shaft cw. Ill try it your way next. thanks again.
 
Glad to hear you got the points in. Go ahead & reset the timing because it will be off if you do it backwards. And, do the 4-step continuity check again.

Don't forget to dress the new points!
 
Nope.

It would just make it hard as h3ll to start or if it started, it would miss under load at operating RPM if it were to far advanced or retarded.
 
I finally see a short bit of spark. only about 1/8 inch. I re set points set the timing according to the book but I no way have 3/16 of blue fire.
 
I must have been doing it right the first time. as it is impossible to do it backwards. I did this the last time after adjusting the points and re setting the time. I stripped the end from some copper wire 14ga. then put it in with the spark plug wire at the cap and rolled it over and held the other end of the wire close to clean grounded spot and got just a small blue spark. So I am getting spark but not very hot. and after changing points from 17 to 15 my vdc is now down around 3.9. Do you think a new coil is in order? thanks again.
 
" I must have been doing it right the first time. as it is impossible to do it backwards. "

Yes it is. You can set the timing on the narrow side of the tang. That's backwards.

The point gap has nothing to do w/ primary voltage.

Check the voltage w/ the points open; it should be battery voltage, 6.35v. W/ points closed, I'd expect to see 3v, but don't worry about 3.9v.

Coils cost $35 these days. And they rarely fail cold. I'd make sure the battery was fully charged. (that's what makes the coil work)

And, just to make sure you're getting full battery voltage to the ignition circuit, pull start it or jump it (see tip # 43)
50 Tips
 
I'm sorry.I have just heard alot of complaining over the years about points systems.Not just on these tractors but everything that has points.I was just wanting to suggest.Sorry. Jay
 
No need to apologize; your opinion is just as valid as mine.

We argue about points vs EI a lot around here.

BTW, if you didn't replace the gaskets, the EI won't work when it gets wet either!
 
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