8N CArb problems

[webbeewood]

not real correct for an ammeter.

inline is what you want with an ammeter.. ie.. remove wire to coil, insert mete rin series.

in any case.. run a hot wire bypass from the battery directly to the coil, if this is a front mount.. then try it. if a side mount then check the wire from the coil to the distrib to make sure the feedthru insulator is not broken.

you can insert a test lamp in that hot wire and see if the lamp blinks.

if it blinks.. circuit is correct. if it never comes on, ckt is open.. if it never goes off, ckt is shorted.

post back.



soundguy

It's a front mount distributor. The battery is a positive ground, so do I run the wire from the + side or - side?

 

[Soundguy]

since the points go to ground.. which would you think?

negative is the 'hot' on a positive ground.


you don't get spark touching like polarities.. since positive is ground.. running positive to one side of the coil, then using the points to connect the other side of the coil to ground wouldn't do much

there's your kettering style breaker ignition 101 class.

soundguy

 

[tthopskin@yahoo.ca]

one day i went to use my fathers 8 N to go 100 yards it took from 9 am to 2pm nice I took every thing apart got it back to the shop finally later we found out what it was ----take the wire from the coil PULL IT out ---THE WIRE CONTRACTS FROM THE CURRENT GOING THREW it try it it cant hurt we put new ones on and would not work used a neighbors his worked and that was what it was the hole time :thumbsup::thumbsup:

 

[Soundguy]

if you got the tractor to fire by pulling the coil wire partially out, you had weak spark or foule dplugs.. by pulling the wire partially out you added to spark gap and raised the KV potential of the spark needed to jump that gap. fouled plugs can frequently be made to fire that way.

way back when you could get a device called a spark intensifier.. it went inline with the plug wire.. it was merely an adjustable air gap.. raised the kv

soundguy

 

[webbeewood]

since the points go to ground.. which would you think?

negative is the 'hot' on a positive ground.


you don't get spark touching like polarities.. since positive is ground.. running positive to one side of the coil, then using the points to connect the other side of the coil to ground wouldn't do much

there's your kettering style breaker ignition 101 class.

soundguy

Wow, you were up late last night, errr, this morning! I got the volt meter out, and I have juice to the coil, so I'm headed to town, to get the coil checked. I'm also going to get one of those little light sticks, to check for current. It's another boiling hot day here in southern Indiana, so I may wait until dark to start back on this old thing.

 

[Soundguy]

no need to head anywhere to check the coil.

you can check continuity of the primary.. shoud be about an ohm to an ohm and a half for 6v.. though consumer grade vom's are junk when it comes to measuring low range ohms. secondary should be 4k to 8k ohms.

if those check, then you need to see if the points are opening and closing.

soundguy

 

[webbeewood]

no need to head anywhere to check the coil.

you can check continuity of the primary.. shoud be about an ohm to an ohm and a half for 6v.. though consumer grade vom's are junk when it comes to measuring low range ohms. secondary should be 4k to 8k ohms.

if those check, then you need to see if the points are opening and closing.

soundguy

OK, I replaced the coil, and still no spark. The rotor is turning, and the points are moving. I checked the current at the ignition switch, and I have no current when the key is on, or when I am cranking the engine. Bad switch? It's only a couple years old.

 

[Soundguy]

shouldn't have replaced the coil without doing the rest of the tests in the thread.. it's a waste of money.

back in post 16 I mentioned using a test lamp to see if you have power thru the switch to the coil and points, and to see what the lamp did.

in post 20 I told you to bypass the switch.. ie.. go straight from the battery to the coil primary.

those are free tests that cost nothing and take little time, but tell you ALOT!

soundguy

 

[webbeewood]

shouldn't have replaced the coil without doing the rest of the tests in the thread.. it's a waste of money.

back in post 16 I mentioned using a test lamp to see if you have power thru the switch to the coil and points, and to see what the lamp did.

in post 20 I told you to bypass the switch.. ie.. go straight from the battery to the coil primary.

those are free tests that cost nothing and take little time, but tell you ALOT!

soundguy

Sorry I've been gone for a while, but it's hot down here in southern Indiana. I've been following our grandson's football games, and decided today is a good day to tackle the Ford again. Traced current down, as you suggested, and started cleaning connections as I went. I turned the key on, and gave it another try, and noticed a little smoke comming from the resister block. I happened to have a new one hanging on the wall, so I changed it. When I hit the key, the motor fired up right away, then died again. Doesn't this sound like a bad regulator? I unhooked the battery, before I burned the resister block up. Do you have any suggestions for the regulator? Change it? It's the last thing that's not new.

 

[Soundguy]

sure.. waste money..... change the voltage regulator.

IT HAS -ABSOLUTELY- ZERO ( 0 ) to do with the ignition..

you can cut the belt to the genny, and wire cut all the wires on the genny and regulator, then start that tractor up and drive away and not have an issue till the radiator gets hot due to no fan turning long before you have power issues with the ignition running on a hot battery.

resistors get hot.. they emit smoke especially when new, as oil flashes off of them.

You unhooked the battery to 'protect' the resistor? Why? have spare time to kill? Turning the KEY SWITCH off cuts power to the coil and resistor assuming you have it wired correctly.

the fact it started up tells you the electrics are working.. Ideally you would have checked spark at moment of stall.

usually when they start and stall it is a lack of fuel issue.

Now.. when you are ready to get this tractor running.. post a thread...

you can strip all the wires off of her, then wire up a couple feet of wire point to point for test purposes and get this straightened out as to whether it is spark or fuel. IE.. diagnose the issue instead of throw parts at it.. or 'guessing' about parts that don't have any bearing ont he situation.

when you are ready to troubleshoot it, let me know. I'll help any way I can.

A roll of black tape and a spool of 14awg wire a few feet long, and a terminal end set, AND a clean carb will make that tractor run assuming you have not changed the timing, have the fire order correct, it has minimum compression needed and a good battery. and the motor and distribuitor internals are within operating tolerances.

soundguy

 

[webbeewood]

sure.. waste money..... change the voltage regulator.

IT HAS -ABSOLUTELY- ZERO ( 0 ) to do with the ignition..

you can cut the belt to the genny, and wire cut all the wires on the genny and regulator, then start that tractor up and drive away and not have an issue till the radiator gets hot due to no fan turning long before you have power issues with the ignition running on a hot battery.

resistors get hot.. they emit smoke especially when new, as oil flashes off of them.

You unhooked the battery to 'protect' the resistor? Why? have spare time to kill? Turning the KEY SWITCH off cuts power to the coil and resistor assuming you have it wired correctly.

the fact it started up tells you the electrics are working.. Ideally you would have checked spark at moment of stall.

usually when they start and stall it is a lack of fuel issue.

Now.. when you are ready to get this tractor running.. post a thread...

you can strip all the wires off of her, then wire up a couple feet of wire point to point for test purposes and get this straightened out as to whether it is spark or fuel. IE.. diagnose the issue instead of throw parts at it.. or 'guessing' about parts that don't have any bearing ont he situation.

when you are ready to troubleshoot it, let me know. I'll help any way I can.

A roll of black tape and a spool of 14awg wire a few feet long, and a terminal end set, AND a clean carb will make that tractor run assuming you have not changed the timing, have the fire order correct, it has minimum compression needed and a good battery. and the motor and distribuitor internals are within operating tolerances.

soundguy

OK, I'm ready to go to school on the electrical parts. I pulled the carb back off, and put the little felt thing around the butterfly shaft, and put it back on the tractor. When I try to start the 8N, the carb floods, so I know it's got gas that far. I went out tonight, about 10 pm, and it did the same thing, it started and died immediately. In the dark, I could see the resister glowing when the key was on, and off when the key was turned off. Lesson learned!
This morning, I put the old points back in, and checked timing and set the points at .20. My book says .15, and the guy at the RV store told me to set them at .25. The old points look good, no burn marks, and I think they are Autolite, if that makes a difference.

 

[Soundguy]

ok.. lets get some issues clarified before we continue... the threads drug on long now..

is this a 5 nipple side mount distribuitor, using a round can coil or a 4 nipple front mount distribuitor with a square coil setting atop of it?

is it 6v or 12v?

1f 12v, what coil type are you using.. IE.. what ohm coil..

wht resistor are you using?

what carb is on the tractor?

soundguy

 

[webbeewood]

ok.. lets get some issues clarified before we continue... the threads drug on long now..

is this a 5 nipple side mount distribuitor, using a round can coil or a 4 nipple front mount distribuitor with a square coil setting atop of it?

is it 6v or 12v?

1f 12v, what coil type are you using.. IE.. what ohm coil..

wht resistor are you using?

what carb is on the tractor?

soundguy

It's a 1947 front mount distributor, 6 volt, Marvel Schebler carb. and the resister is a replacement from the Ford Tractor Shop, that went out of business a few years ago. The package info says: Resistor Assembly ignition coil for 8n prior to s/n 263844, part number A8NN12250A. I have the carb back off the tractor again, and I'm going to clean it again, and check for plugged passage ways. I had been trying to start it again, before I pulled it, and checked the intake manifold. It was dry, and the plugs were dry, but the bottom of the carb had gas in it. I'm sorry I'm taking a lot of time to try to find out what's going on with my 8N, and I have owned it for 22 years now. I have always been able to find the trouble and fix it, and this is the first time I've put new parts on it, other that a few new batteries and a new coil that went bad several years ago, and new points and plugs every year. I have a manual, the original from 1947, and this is the first time I've needed help. I want to thank you for the patience and time you spent trying to help me get up and running again.

 

[Soundguy]

OK.. I'm puzzled why you set your points at .020 when your book tells you .015

You keep doing stuff like that and you WON'T EVER get this tractor running.

.025 is for a SIDE MOUNT distribuitor 8n.

.015 is for the front mount model you have.. just like your book tells you.

check spark.

post back

soundguy

 

[webbeewood]

OK.. I'm puzzled why you set your points at .020 when your book tells you .015

You keep doing stuff like that and you WON'T EVER get this tractor running.

.025 is for a SIDE MOUNT distribuitor 8n.

.015 is for the front mount model you have.. just like your book tells you.

check spark.

post back

soundguy

The machanic at Anderson's John Deere (they are the ones that bought the Ford business) told me to set the points at .25. When I told him my book said .15, he told me he had been doing it his way forever. I guess I should have stuck with the book. I'm leaving in the morning, for a few days, and I'll be working on the tractor Friday. See you then.

 

[Soundguy]

ford advice from a JD mechanic.. did he have a smile on his face when he told you that..

soundguy

 

[webbeewood]

ford advice from a JD mechanic.. did he have a smile on his face when he told you that..

soundguy

No, he's actually the owner of the "bought out" Ford store. Then again, that may be whe he was bought out.
OK, We got back early this evening, and I tried my new tools out. ($1.97 current checker) and found I was getting juice to the coil. I had a new distributor cap in the barn, so I switched. It fired up immediately, and ran like a watch. I looked at the old distributor, and can't see any cracks or distortiations. If I change spark plug wires, (The old ones are at least 22 years old, or older) I'll have almost a new tractor. Heck, I might as well paint it now.
Anyway, thanks for all your help, and I'll check back in once in a while to see if anyone breaks my record for posts. It has been a learning experience, and I got some education from the Master. Thanks again,
Don :thumbsup:

 

[Soundguy]

might have been carbon tractos inside the cap.. or the cap was out of round and not fitting good. seen that. darn chinese caps.. etc.

glad you stuck with it and got it going.

soundguy

 

[clemsonfor]

Holy crap we went through all this and you never put new wires or cap on the thing? I thought you had repeatedly said that the plugs were dry, meaning that it wasent getting fuel past carb, which is why you thought is was carb issue, if it would not run on carb cleaner sprayed in there, i think we can all say were stupid for not telling you to put $25 worth of tune up parts on it?

 

[Soundguy]

Holy crap we went through all this and you never put new wires or cap on the thing? I thought you had repeatedly said that the plugs were dry, meaning that it wasent getting fuel past carb, which is why you thought is was carb issue, if it would not run on carb cleaner sprayed in there, i think we can all say were stupid for not telling you to put $25 worth of tune up parts on it?

not really.. go back and read thru the thread.

he's had a BUNCH of issues on this tractor.. not just the cap. as late as post 16, he didn't even have power thru the switch...

compound problems are always the hardest to solve.. you have to work thru one at a time without doing a shotgun parts change so that you can continue diagnosing it. this one was a realt tweaker.. but.. it's running.. and that's what counts..

soundguy