Pertronix ?

[HowieFHS]

Hello,
Have Pertronix kit 1247xt on 9N (front mount, pos grnd). Have cruised the archive for hours late nights, am losing sleep over this. Problem: Tractor will run for 2 or 3 hours, will not get spark to start up again after this time. Details: plugs have much unburnt carbon on them; will start and run for another 2-3 hours with new or cleaned plugs; removed ballast resistor as machine would not start at all with it; runs rich (Zenith carb adjusted to specs); audible "snap" when ignition key is turned to off position, and with plug removed and grounded spark is observed coinciding with this sound; no spark supplied to plugs during cranking. I think that covers it. Wrote to manufacturer and they have not encountered this problem. Hoping someone out there has some ideas, other than going back to points! Which I am about ready to do. I switched to electronic because I believed the claim for hotter spark would help the running rich problem. Instead, I still have that problem and have gained a new one. Just my luck.

 

[Anonymous-0]

I had that same problem. It was the negitive wire on battery where it connects to the block. It was a little loose and after some vibration, would quit. Take it loose, clean the block and reassemble.

 

[souNdguy]

Points are looking good right now huh!

I see a few issues.

1, if you are running rich, that will really foul your plugs with carbon.

2,Carbon fouled plugs don't spark well, as the spark just shorts right thru the carbon buildup instead of jumping the gap.

3, the 6v front mount units are ABSOLUTELY sensitive to voltage. Less than about 4.5V and the electronics won't work. That doesn't leave much leeway for a weak or cold battery.. or the starter dragging the system down a bit.

4, While I've not had my hands on many of the units.. i do believe that some require full power to the module.. but still require the balalst resistor for the coil. I fthat is so.. your coil may be damaged from running without the resistor.. timing is almost right.. IE.. runs 1-2 hrs, then won't go till it cools down? sound close?

5, Hotter spark is not a soloution for running rich. in fact.. in a rich condition.. usually a weaker spark 'will work'.. etc.. however simply having more spark potential voltage does nothing to help a rich carb setting. You REALLY need to get the carb straightened out. Just stating that the carb is adjusted to spec don't mean much.. that's whay carbs are adjustable.. if you could simply magically set them perfectly at the factory.. they would.. and wouldn't give us knobs on them to fiddle with. I've seen ms carbs that needed up to a whole turn different to work right.. IE .. anywhere between 1.25 to 2.25 turns.. etc..

Soundguy

 

[Dell (WA)]

Howie..........congratulations, you have just found out the NEGATIVE about the Pertronix. Yer HOT-SPARK Pertronix without the "infamous ballast resistor" has OVERHEATED yer weaksister squarecan ignition coil and melted the internal insulative tars and SHORTED out the primary coil windings.

It takes about 1+hr to melt yer insulative tars. Amazingly enuff, an overnite cooldown frequently re-insulates the coil windings and will restart in morning with lots of "authority" of blue-snott sparkies. And then will MELT the coil tars again inna'bout 1-hr and cause it to stop.

The ONLY CURE is new coil and re-installing yer ballast resistor to control the coil heating. Unfortunately, once the tars starts to melt, there ain't NO cure except replacement.

Pertronix LIES. They know their 6-volt frontmount conversion is marginal at best. They have LOUSY installation instructions fer the electrically challenged newbie. Their 6-volt module will NOT WORK on the 3-volts that the "infamous ballast resistor" supplies to the top of the OEM 6-volt squarecan ignition coil.

I can replace alotta frontmount points ($5, cheap) in 15-minutes fer the braggin' rights of a Pertronix electronic ignition that don't work with reliability. This ain't sour grapes, I made by hand, my first electronic ignition in 1962 for my Dodge D-500 hemi-V8 and it worked like supposta. I also have CD electronic ignition in my HOT 1969 BMW 2002. (165hp on dyno at 6500rpms, OEM hp=110)........Dell, yer self-appointed sparkie-meister

 

[JMOR]

"Have Pertronix kit 1247xt on 9N (front mount, pos grnd)."

"xt" means external remote automotive coil.

 

[HowieFHS]

Thanks for the input everyone. The kit I have replaced the square can coil with a round one, and there is no cool down, it just will never fire again unless I change or clean the plugs. Guess it is back to the points. I suppose I"ve lost $150 worse ways...just can"t remember any right now

 

[HowieFHS]

Should I put the ballast resistor in the lead wire (neg-)going to the coil primary? Did the full 6v smoke the round can coil that came with the kit? I wasn't able to get spark with resistor in circuit as originally wired to block. Is there another way to wire it?

 

[souNdguy]

I see there is a problem here.

We did not know you are using the side coil kit... you had mentiond frontmount.. but that's it, and are now dribbling out the info we needed to make an informed diagnosis.. which is now skewed to a possibly wrong conclusion...

Collect your thoughts, and make a new post of ALL the pertinant info. That's when I'll take a look at it again.

Soundguy

 

[Dell (WA)]

Howie.........as a general rule, all ROUNDCAN ignition coils are fairly bulletproof; whether 6-volt or 12-volt; hether used with points or Pertronix points module. Understand?

And NO, you should NOT need enny frickin' ballast resistor to run yer Pertronix iff'n you bought the "full system". READ yer Pertronix instructions AGAIN.

Based upon yer vauge and limited description of yer Pertronix failure, yer Pertronix module is BAD. That is why you spend $150 for factory support. Pertronix LIES. SEND IT BACK.

I gotta comment on yer carb and complaint about running RICH. Much to the dismay of environmental bureaucrats, each carb must be adjusted to match the flow characteristics of the engine it is being used with. You can NOT just turn screws to some arbitrary adjustment that you read in a book or manual. Understand?

Yer complaint about running rich and having to change yer sparkies everytime yer engine quits running is BOGUS.

Everytime yer engine quits because of yer BAD Pertronix module and you try to re-start it and it fails to re-start, you've FLOODED yer sparkies with invisible no-lead contaminates. Which is why you haffta change yer sparkies because whatever sparkies you might have are leaking down the white center electrode insulator.........respectfully, Dell, yer self-appointed sparkie-meister

 

[Anonymous-0]

Is this a 6Volt or 12Volt kit that you have? The part no. that you listed is for 12V neg. grd. if 6V positive ground, your no. should have a P6 somewhere in the kit designation? Positive ground won't work in the regular 1247XT kit? Just wondering what you really have there, Jim.

 

[Bob]

I skimmed over this thread really quickly, and I gather this is a 6-Volt (+) ground system with a round-can coil conversion, correct?

Some things to check... what is the voltage at the switch (- side) of the coil WHILE CRANKING, in the "no-start" condition?

Take a spare spark plug, and bend the gap WIDE... (at least 1/8"+)... connect one of the spark plug wires to the test plug, and ground the plug and crank the engine. Do you have a good, hot spark jumping the BIG gap?

Another thing... the Pertronix units won't fire if the module is too far away from the magnet wheel... they send a plastic feeler guage with the normal Pertronix units... did you get one with your's, and is the air gap adjustable?

The bottom line is the module can be VERY CLOSE to the magnet wheel, but never touching.

Let us know what the voltage to the coil is at cranking, and if you have a HOT spark... if the voltage is reasonble, and NO spark when warm, it's time to pester the Pertronix folks into exchanging the module... they have something like an 18-month warranty, and there's NO reason for you to have to put up with a "fussy" one that doesn't like to work when it's warm.

HOWEVER, if the battery is weak, or the starter draws a LOT of current during warm cranking, for some reason, and pulls the voltage way down, the electronic gizmo just ain't gonna make the coil spark.

 

[HowieFHS]

Sorry then... yes, this the kit advertised on the link from this forum as part number 1247xtp6, Pertronix calls it an Ignitor module. Here is what they sent to me in an e-mail: I've attached an instruction sheet for a 6 volt positive ground system. The
only time you would need the ballast resistor is if you don't have at least
1.5 ohms in your stock coil. If you need to run a resistor, then you would
install it between the positive side of the coil and ground. I short one
side of the resistor would to ground or positive post of the battery and the
other side would go to the positive post of the coil.
Thank you,
Tech Dept
I will check voltages at the switch per post by Bob, and am leaning towards a bad module suggested by Dell. I have spent alot of time removing the Zenith carb and adjusting the float position both relative to the top plate and the needle valve. It takes only a frog's hair to make the difference between running rich and starving. I haven't just "turned a few knobs" as suggested. It is very frustrating and honestly, I appreciate all the advice, I just want to get the thing running at least as well as it did before I put this fancy ignition kit in.

 

[souNdguy]

Yep.. nothing like spending a cubic foot of money just to get a machine that runs worse.

many of my tractors are stock 6v.. and will stay on points because of that.. at least until 'logic' for lower voltages finally trickles down to the automotive aftermarket..

soundguy

 

[Jason1(Pa.)]

I went threw problems with the Pertronix last year and Im back to the points. When I would hit the starter button it cause the the battery to go below 6 volt(like it should) however if you don't have 6 volt you won't get any spark. If I pulled the tractor to get it to start it would run cause there was no drain. I have Pertronix on my Farmall M (12 volt) and love it..Oh,well it sounded too good to be true. Thought I would never have to mess with the front mounts again!!

 

[Britcheflee]

OK Dell.....I have to ask....what on earth is a weaksister? :?

And, can you explain the invisible contaminates that get on the spark plugs when you flood the engine a bit more for me?


Lee

 

[Dell (WA)]

Lee........what do you think a weaksister would be? A descriptive term for "less than robust", maybe?

Gasoline isn't just gasoline you know. It has various additives including "no-lead" that condenses on the white center insulator. This "no-lead" salt is conductive and NOT insulative. Therefore when FLOODED all that invisible "no-lead" salt leaks them lazy sparkies down the outside of that white insulator instead of JUMPING the GAP and igniting the gasoline vapor like it should. You CAN NOT SEE this "no-lead" salt but it is there and works just as described.

You can BURN the "no-lead" contaminates off the white insulator with a plumbers torch, or do it the simple way and swap flooded sparkies one-atta-time in a hot running engine using 3-good sparkies to keep the engine running while the flooded sparkie is burned DRY and CLEAN. Capiche?.........Dell, yer self-appointed sparkie-meister

 

[Anonymous-0]

Your insulative tar idea is suspect.Wire used to wind coils has to have a coating,One I can think of Formvar.The tar is simply a potting compound.Steel can be heated to the point where it is no longer magnetic.If a stovepipe thermometer gets heated to about 450 degrees the magnet on the back of it loses all magnetism.Wire coatings that are overheated to failure do not heal themselves.Overheated AC motors will slow down a bit and blow fuses.If they are allowed to cool the fuse blowing stops.Ignition coils operate on AC voltage,the waveform can be seen on an oscilloscope.I think that magnetism is affected when the winding and the iron core gets hot plus the formvar coating fails after repeated heatings.Shorted turns result and the current increases and causes more shorted turns.

 

[JMOR]

I wonder about the 450, as my book says "Curie Temperature, the temperature at which iron loses it's magnetic properties is 1500 deg F". 815C

Many transformer core materials have Curie temps in the 500 to 900 deg C (930F to 1650F) range.

Solder melts at ~375 to 400F.

Copper melts at ~ 1100F.

Iron red ~ 800F

Iron melts ~ 2800F

Suspect the mag-wire insulation coating is the problem (usually is in motor/generator armatures).
We re-wind but don't replace laminations.

 

[Britcheflee]

(quoted from post at 22:53:49 12/05/07) Lee........what do you think a weaksister would be? A descriptive term for "less than robust", maybe?

Gasoline isn't just gasoline you know. It has various additives including "no-lead" that condenses on the white center insulator. This "no-lead" salt is conductive and NOT insulative. Therefore when FLOODED all that invisible "no-lead" salt leaks them lazy sparkies down the outside of that white insulator instead of JUMPING the GAP and igniting the gasoline vapor like it should. You CAN NOT SEE this "no-lead" salt but it is there and works just as described.

You can BURN the "no-lead" contaminates off the white insulator with a plumbers torch, or do it the simple way and swap flooded sparkies one-atta-time in a hot running engine using 3-good sparkies to keep the engine running while the flooded sparkie is burned DRY and CLEAN. Capiche?.........Dell, yer self-appointed sparkie-meister

Oh.... :?


Does this qualify as a weaksister?


http://www.funnyphotos.net.au/female-body-building/

:shock:
Lee

 

[Dell (WA)]

36 coupe.........my vote is on the potting tar and that they CHANGED the potting tar formula to a lower melting point tar for eazier assembly at factory. Yes, both the primary and secondary windings wires are varnish coated. You called it Formvar.

And while it is true, you can see a ringing waveform on the O'scope, that is NOT how ignition coil operates. It is simply a MAGNETIC FIELD COLLAPSE when the points OPEN that induces the ultra high voltage spike outta the many fine turns wire of the secondary........Dell

 

[Dunk]

(quoted from post at 07:48:43 12/06/07) Overheated AC motors will slow down a bit and blow fuses.

My tractor dosen't have an Air Conditioner (well only this time of year), or an Air Conditioner motor, I sure would like to see a picture of one.

(quoted from post at 07:48:43 12/06/07) Ignition coils operate on AC voltage,the waveform can be seen on an oscilloscope.

Where does the Ignition Coil get the AC voltage (from the DC battery)?

Mine doesn't have an inverter either.


I do have some old radios that have oscillators in them.

 

[Anonymous-0]

A magnetic mount stove pipe thermometer will not stay on the stove pipe after the temperature has run up to 450 degrees.The heat destroys the magnetism.When ignition coils overheat I think magnetism is affected.Running a tight point gap will cause coil heating.Reason, the coils on time is increased.

 

[JMOR]

We see eye to eye on heat destroying magnetic properties, it is just the temperature in question that there appears to be less than eye to eye agreement. On the other side of that flue pipe metal is a temp 2X to 3X the 450F, so what does the magnet see (thermometer is surrounded by room air). Aside from your falling thermometer, there is ample data to indicate that core materials in motors, alternators, transformers, etc. operate daily at temperatures approaching melting their solder joints, which will happen well before the magnetic properties will be affected. Not to mention that the magnet wire insulation material is rated at only a fraction of the solder temp melt point and an even smaller fraction of the magnetic material Curie temp.
Please note Alternator & starter temps in chart:

I've added mag wire properties, below.
I wonder about the 450, as my book says "Curie Temperature, the temperature at which iron loses it's magnetic properties is 1500 deg F". 815C

Many transformer core materials have Curie temps in the 500 to 900 deg C (930F to 1650F) range.

Solder melts at ~375 to 400F.

Copper melts at ~ 1100F.

Iron red ~ 800F

Iron melts ~ 2800F

***Magnet wire insulation ranges from 105C (221F ) for enamel & Formvar, to 200C ( 392F) teflon , to 240C (464F) Aircraft Mil Spec Polyimide

Suspect the mag-wire insulation coating is the problem & long gone well before metal core problems (usually is in motor/generator armatures).
We re-wind but don't replace laminations.

One can research failure mechanisms in transformers all day long and still find that the overwhelming cause is Insulation failure.

Lacking evidence to the contrary, I'm sticking with wire insulation as failure mechanism in these ignition coils.

 

[Anonymous-0]

If insulation failure happens the coil would not recover and deliver a good spark when the coil cooled.I remember some hot starting problems with Gm cars.Heat shields were used.I am not saying that magnetism fails but that it is weakened when the coil overheats.30s Ford service bulletins mentioned heating coils for 3 or 4 minutes to check for hot failure.This may be the cause of all the ignition problems that Ford tractor owners seem to be having now.I did service work on two farms taking care of tractors and equipment.Most of the tractors were Farm Alls.There was 1 Ford 8n in the mix and it never had any ignition problems in 6 years.The 8n was used to plow a long driveway and never gave any starting problems.I think most ignition problems are self made by owners who know nothing about ignition systems and dont seem to want to know how they work.The usual approach is to replace all the parts in the ignition system and then ask why the tractor wont start.

 

[JMOR]

I go along with most of what you have said in the last post of yours, especially the last sentence.
You mentioned that if wire insulation were the problem, that it would not work again after cooling. It is always possible that the movement of wires due to expansion(heating) & contraction(cooling) of the potting materials could push wires into contact & move them apart. Have you noticed that oil filled coils seldom exhibit the problems that the epoxy and resin filled ones do? Magnets once burned in the fireplace do not become magnets again when they cool. The material used as a core in coils, motors, transformers, etc. is specifically chosen to have little hysteresis effect (don't want it to be a permanent magnet).

Copper windings have a positive temperature coefficient and when the temperature goes from 68F to 300F, the resistance change is such that current will be reduced to 67% of its previous value. Energy stored in the coil is equal to 1/2 L x I X I, which means the energy falls off with the square of the current reduction and over that same 68 to 300F range energy is now ONLY 45% of its previous value. Unlike the heating of a magnet or the rupture of insulation, the copper WILL return to its previous resistance when cooled. This (in my humble opinion) is most responsible for the coil seeming to "heal its self" after cooling.

 

[Anonymous-0]

The points interupt the dc voltage and produce an alternating voltage.Go to a tune up shop and ask to look at ignition scope.You will see a very complex alternating voltage on the scope screen.

 

[Anonymous-0]

The AC refers to alternating current not air conditioning.You must have been into the beer again.

 

[TheOldHokie]

(quoted from post at 05:37:04 12/08/07) The points interupt the dc voltage and produce an alternating voltage.Go to a tune up shop and ask to look at ignition scope.You will see a very complex alternating voltage on the scope screen.

The points are a SWITCH. They do not produce alternating anything. The current is turned ON and OFF by the points which produces a collapsing magnetic field in the coil and an induced high potential direct current voltage in the secondary. The trace you see is that voltage as it builds and then decays over time.

TOH

 

[JMOR]

(quoted from post at 18:13:06 12/08/07)

(quoted from post at 05:37:04 12/08/07) The points interupt the dc voltage and produce an alternating voltage.Go to a tune up shop and ask to look at ignition scope.You will see a very complex alternating voltage on the scope screen.

The points are a SWITCH. They do not produce alternating anything. The current is turned ON and OFF by the points which produces a collapsing magnetic field in the coil and an induced high potential direct current voltage in the secondary. The trace you see is that voltage as it builds and then decays over time.

TOH

Actually, I don't want to jump in the middle of you two fine folks, but I will say that in a way you are both sorta right. At the instant the points open, we have a resonant circuit consisting of a coil (inductor) & a condenser (capacitor) and the resonant circuit will ring like a bell and the waveform will look sinusoidal UNTIL the arc is established at which point a DC current passes thru the plasma until most of the energy of the coil's magnetic field is depleted (so much that the arc can't be sustained) after which it will "ring" again until all the energy is dissipated in losses or the point close again, which ever comes first. Then it all starts over.
If asked, I will post an oscilloscope waveform.
Sorry if I'm interfering.
Marry Christmas to ALL!

 

[TheOldHokie]

Nice to know the details - that's why I'm a computer scientist not an electrical engineer :roll: If I understand you correctly whatever the resonant waveform it produces it's still DC :?:

TOH

 

[OKDAD]

An alternating current (AC) is an electrical current whose magnitude and direction vary cyclically, as opposed to direct current, whose direction remains constant.

So let's see....the tractor uses a battery so it doesn't have alternating current (AC)???? Yet you need an ignition coil (transformer) to create the high voltage for a spark....but transformers only work with AC! So you use a switch (points) to get the coil current to change creating.....AC!!!

No it's not a sinsuoidal waveform but it does alternate! My $.02.

And yes I stayed at Holiday Inn Express.

 

[Bob]

(quoted from post at 00:24:06 12/11/07) An alternating current (AC) is an electrical current whose magnitude and direction vary cyclically, as opposed to direct current, whose direction remains constant.

So let's see....the tractor uses a battery so it doesn't have alternating current (AC)???? Yet you need an ignition coil (transformer) to create the high voltage for a spark....but transformers only work with AC! So you use a switch (points) to get the coil current to change creating.....AC!!!

No it's not a sinsuoidal waveform but it does alternate! My $.02.

And yes I stayed at Holiday Inn Express.

Ever heard of a PULSE transformer, LOL!

 

[OKDAD]

Of course! And a pulse train is just another form of AC. Similiar to what vibrators did in old car radios.

 

[TheOldHokie]

Well this is beginning to smack of the long running debate we've had amongst ourselves here at work about whether a "digital" signal is truly digital or really analog :evil:

After doing a little reading and revisting LC circuit behavior (Gawd - E&M in freshman year Physics I think - no wonder it was buried away) it does indeed seem there is some element of alternating current in the secondary of the coil. I took this question to my resident EE in the office next door and he was reluctant to catagorize it as "really" AC although he acknowledged the low level behavior. He promised to escalate the question to a more learned colleague in the EEEL lab at lunch.

TOH

 

[OKDAD]

The world is analog. However parts of it are compelled to operate in a digital manner.

 

[TheOldHokie]

(quoted from post at 10:04:59 12/11/07) The world is analog. However parts of it are compelled to operate in a digital manner.

Indeed! The electron flow is "analog" - the meaning ascribed to it (signal) is interpreted digitally.

TOH

 

[serge]

Hi,
I do have the same system 1247XT pertronix with negative ground.
was good for about 1 year than do not have a good spark anymore
luky I got it from Ebay they will replace it but told me they only last for a few years

make sure you do not have any bad connections