Follow up for those with "tractor starting issues"

oldtanker · May 26, 2015

Several people posted about starting problems on gas tractors. Not very shocking there were several people who gave them info to help them out. Folks on here are very good about that. I had a hard starting gas tractor here with 2 others that started very well. The 2 others I had converted to 12 volt and rewired both tractors. This other one I really didn't do anything to it just put up with the hard starting issues, was converted to 12 volt when I got it. I was going to rewire it the other day but got rained out. Well today I got on it. I know the wiring wasn't great but I didn't realize it was that bad. Anyway once it was done it popped right off like it should while it was cranking instead of only when you let off the starter button.

So guys with stating problems check everything out. I'm pretty sure the PO converted this tractor to 12 volt because of starting problems. A lot of times 12 volt will make em start like new but unless you correct any other problems it's only masking those issues.

Rick

Steve@Advance · May 26, 2015

Rick, good to hear you got it going!

Wiring is always a problem with the old tractors, especially when they sit out in the weather, mice get into
them, PO's take too many shortcuts...

Anyone with wiring problems, be brave! It's not that hard to understand. A cheap incandescent test light can
diagnose about 90% of any electric problems. Just a matter of getting in there and figuring it out!

ss55 · May 26, 2015

If it wouldn't fire until you let off the key, was the coil resistor bypass circuit poor or missing?

tomturkey · May 26, 2015

tell me more about this "bypass" circuit. My sons farmall H always wants to fire as you let off the starter button. Draw mw a picture, it is still 6 volt. thanks, gobble

kevinj54 · May 26, 2015

(quoted from post at 19:57:39 05/26/15) tell me more about this "bypass" circuit. My sons farmall H always wants to fire as you let off the starter button. Draw mw a picture, it is still 6 volt. thanks, gobble

If ya gots a magg & 12 volts you may spin it to fast for the impulse to catch causing this issue till you let off the button so it can slow down.

oldtanker · May 26, 2015

(quoted from post at 16:18:00 05/26/15) If it wouldn't fire until you let off the key, was the coil resistor bypass circuit poor or missing?

There is no coil bypass on that tractor. Never was. The problem was 1. wired wrong and 2 wiring was in such bad shape. Basically because the wiring was goofed up it wasn't getting enough voltage to the coil to fire the coil while the tractor was cranking. As you took your finger off the starter button the engine was still spinning and all the power was available for the ignition system. Not the first one I've seen like that.

Rick

oldtanker · May 26, 2015

(quoted from post at 16:57:39 05/26/15) tell me more about this "bypass" circuit. My sons farmall H always wants to fire as you let off the starter button. Draw mw a picture, it is still 6 volt. thanks, gobble

Clean tight and bright. All connections. If it's a battery ignition (distributer system, not a mag) dirty connections, bad/dirty points, poor wiring and such can cause all kinds of interesting starting problems. The battery ignition H's did not have a coil bypass circuit. You mostly only saw those on cars and trucks.

What happens is because of some fault (dirty connection, faulty wires, dirty/bad points) is that the system isn't feeding enough voltage to provide good spark while the starter is engaged. A lot of the time when someone does a 12 volt conversion it's because of that type of problem. If they don't fix the problem all they are doing is masking it with 12 volt. Eventually it will get bad enough that it will give problems there too. I always tell someone wanting to convert to make sure everything is 100% BEFORE converting. In other words the conversion should be an upgrade not a band aid.

Rick

Geo-TH,In · May 26, 2015

Not sure when farmall went to a coil, my 1950 farmall C has a mag. So the old mags don't have a ballast by-pass circuit. A by-pass circuit shorts out the ballast resistor when starter is cranking. This applies the full battery voltage, minus a few volts, because the battery cranking voltage is usually less than 12v. This is how all the old cars were wired back in my day. The ign switch was responsible for applying full voltage to coil when starting.

I used a diode to apply 12 volts to coil when the starter is on. I connected the anode to the starter wire, the cathode to the + coil wire. Some starter solenoids have a terminal for this purpose, mine didn't. For me, the diode was the simplest way to get the job done.

Sometimes I think 12v conversion is spinning the starter too fast. I slowed my farmall C down by using a 185 cca lawn mower battery. I like the way it starts turning over slower. Just my opinion, but I think the old tractor were designed to start using a crank, lot slower than even a 6v battery. I hand started my share of old tractors and kick started old motorcycles. Nothing fast about that.

RandyB(MI) · May 26, 2015

Well put !

oldtanker · May 26, 2015

(quoted from post at 18:17:33 05/26/15) Not sure when farmall went to a coil, my 1950 farmall C has a mag. So the old mags don't have a ballast by-pass circuit. A by-pass circuit shorts out the ballast resistor when starter is cranking. This applies the full battery voltage, minus a few volts, because the battery cranking voltage is usually less than 12v. This is how all the old cars were wired back in my day. The ign switch was responsible for applying full voltage to coil when starting.

I used a diode to apply 12 volts to coil when the starter is on. I connected the anode to the starter wire, the cathode to the + coil wire. Some starter solenoids have a terminal for this purpose, mine didn't. For me, the diode was the simplest way to get the job done.

Sometimes I think 12v conversion is spinning the starter too fast. I slowed my farmall C down by using a 185 cca lawn mower battery. I like the way it starts turning over slower. Just my opinion, but I think the old tractor were designed to start using a crank, lot slower than even a 6v battery. I hand started my share of old tractors and kick started old motorcycles. Nothing fast about that.

My Farmall M has no resistor inline. Round can coil that says right on the coil 12 Volt no external resistor needed.

My 8N's had a factory ballast resistor that after it starts and run get warm and resistance increases. Neither has a dedicated bypass on the ignition circuit. Cars were generally a little more complicated than a tractor. Little things like bodies, doors windows, heaters, wipers and radios made them completely different.

Actually they were at one time designed to start with a crank. Then some fool (hero in my book) figured out how to start an engine with an electric motor and a storage battery. But by the mid 40's on they were designed to start with a starter but they did provide a crank as a backup.

I've kick started motor cycles and hand crank started a few tractors. It was an overrated experience! :lol: :lol:

Rick

David G · May 26, 2015

I am a die hard 12V conversion person, but any starting problems should be corrected first. There is no reason an engine should not start on 6V, most of the time. I like 12V for the convenience, and so I can run more advance for the economy and power. My 12V H would not fire with a very bad battery until I let off the starter, then it hit right off.

teddy52food · May 26, 2015

If the starter spins it so fast that the impulse doesn't catch, the mag should be making a hot spark without the impulse.

David G · May 26, 2015

I do not know of a coil with an operating voltage less than 6V. The ballast resistor is typically for 12V systems, it allows the use of a 6V coil during normal operation, and 12V for starting.

I think you are out of luck with the 6V and a ballast resistor.

Convert to 12V, you will never regret it.

oldtanker · May 26, 2015

(quoted from post at 20:51:36 05/26/15) I do not know of a coil with an operating voltage less than 6V. The ballast resistor is typically for 12V systems, it allows the use of a 6V coil during normal operation, and 12V for starting.

I think you are out of luck with the 6V and a ballast resistor.

Convert to 12V, you will never regret it.

David, the Ford N series tractors with the square can coil:

http://www.yesterdaystractors.com/9N12024_Coil-Six-Volt_450.htm

used a resistor in line.

http://www.yesterdaystractors.com/A8NN12250B_Resistor-Assembly-Ignition-Coil_4372.htm

So now you've seen a 6 volt coil that used a resistor.

Now as for cars most later cars in the 60's and 70's used a coil that used about 8 volts, not 6. So you still had to use a resistor of some type to reduce voltage to the coil. You will note that you have still today 6 volt round can coils, "12 volt" use with a resistor (8 volt) and 12 volt no external resistor required.

Rick

oldtanker · May 26, 2015

(quoted from post at 20:51:36 05/26/15) I do not know of a coil with an operating voltage less than 6V. The ballast resistor is typically for 12V systems, it allows the use of a 6V coil during normal operation, and 12V for starting.

I think you are out of luck with the 6V and a ballast resistor.

Convert to 12V, you will never regret it.

Oh and by the way, I'm a big believer in 12 volt conversions and completely agree. Make sure the starting and ignition system is in top condition BEFORE converting. Don't use a 12 volt conversion as a band aid for your tractor. Eventually the problem will get bad enough that even with 12 volt it will give you problems.

Rick

Blackhole49 · May 27, 2015

If the starter spins it too fast for the mag to work, what happens once it is running and really spinning?

Geo-TH,In · May 27, 2015

That's weird, I think my Jubilee came from the factory with a 6v battery, voltage
regulator, 6v coil and I think a + ground. Someone before me converted it to 12v
alternator, installed a ballast, used the old 6v coil and negative ground.

The practice of by passing the ballast in old cars was done with Ign switch. Tractors
used a special terminal on solenoid. Some wire in a relay or in my case use a diode, to
wire around ballast during cranking making hotter than normal spark.

Tractor data shows both the 8n and Jubilee came from factory with 6 volts.
8n tractor data.

Follow up for those with "tractor starting issues"

oldtanker

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Steve@Advance

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ss55

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tomturkey

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kevinj54

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oldtanker

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oldtanker

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Geo-TH,In

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RandyB(MI)

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oldtanker

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David G

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teddy52food

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David G

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oldtanker

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oldtanker

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Blackhole49

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Geo-TH,In

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