Ignition system

Tractor Rod

Well-known member
I know this sounds like a stupid question. I’ve bought a couple of cubs and this latest one had a battery on it that tested when I first put on the volt meter of 12 volts beginning but steadily started dropping until it finally held at 3 volts. I want to charge the battery but how do I tell if this is an original 6 volt system on this 48 model or if someone converted it to 12. The battery has the labels worn off it and has 3 cells so I’m guessing it is 6 volt??? It doesn’t have an alternator so that is maybe a sign it’s still original 6 volt??????

Please advise this brain dead 72 year old!

Thanks.
 
3 cells/caps = 6v. From what you stated, my guess is the battery is bad. A 48 would originally had a magneto but could have been changed to battery ignition. Can you post some pics? JMHO Stan
 

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3 cells/caps = 6v. From what you stated, my guess is the battery is bad. A 48 would originally had a magneto but could have been changed to battery ignition. Can you post some pics? JMHO Stan


Stan,
Thanks so much for your help. I recently had a stroke and I’m slowly getting back to my normal activities and sometimes the simplest things have escaped me. Pictures are attached. Thanks for your help and assistance!
 

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Hi,
A 1948 Cub came with a generator, and a cutout, or Relay IH called it, on top of the gen.
The 6 volt starters and gens had a plate on them with the model number at the left side of the plate.
The model number of the starter is usually 1109603.
The model number of the gen is usually 1101355. The Relay has 3 connections for wires.
Below is a page from the 1950 Cub owner's manual showing the electrical system with the hood off.
You can look and see if it looks the same as the picture.

Your picture above shows the Cub has the voltage regulator, which came out in mid 1950, and is mounted where yours is, on a mounting bracket.
The voltage regulator has 4 connections for wires.
It has a Battery Ignition unit also, which came out in mid 1950, but some Cubs were changed to it.
I would check the Cub serial number, using a good light, and see if is newer than 1948.
Below is a page from the 1955 Cub operator's manual showing the system with Battery Ignition, and the voltage regulator. :)
 
Last edited:
I know this sounds like a stupid question. I’ve bought a couple of cubs and this latest one had a battery on it that tested when I first put on the volt meter of 12 volts beginning but steadily started dropping until it finally held at 3 volts. I want to charge the battery but how do I tell if this is an original 6 volt system on this 48 model or if someone converted it to 12. The battery has the labels worn off it and has 3 cells so I’m guessing it is 6 volt??? It doesn’t have an alternator so that is maybe a sign it’s still original 6 volt??????

Please advise this brain dead 72 year old!

Thanks.
It's hard to say what might have been changed since this tractor was made. Your pics are as Glen said, battery ignition, originally battery would have been pos ground. What is the status of the tractor, running or not? What do you want to do to it? The ID of the generator and starter is worth noting but it's very common for 6v starter to be in use with a 12v battery. Pos or neg generator output can be changed by polarizing the generator but a 6v generator will not keep up a 12v battery. Guessing from what you said, someone could have charged the 6v battery with a 12v charger. Pos grounded battery should have the + (output) side of the coil connected to the post on the distributor but I've heard of it being done differently. Give us a few more details on your intentions and someone (probably several members) will chime in with some advice. JMHO Stan
 
It's hard to say what might have been changed since this tractor was made. Your pics are as Glen said, battery ignition, originally battery would have been pos ground. What is the status of the tractor, running or not? What do you want to do to it? The ID of the generator and starter is worth noting but it's very common for 6v starter to be in use with a 12v battery. Pos or neg generator output can be changed by polarizing the generator but a 6v generator will not keep up a 12v battery. Guessing from what you said, someone could have charged the 6v battery with a 12v charger. Pos grounded battery should have the + (output) side of the coil connected to the post on the distributor but I've heard of it being done differently. Give us a few more details on your intentions and someone (probably several members) will chime in with some advice. JMHO Stan
Stan & Glen,
Thanks to all for your information. My intent is to get it running and then paint it. Surprisingly the gas tank is very clean and the skin is in great shape. It has a cultivator on it and I’m thinking of taking it off and selling it to offset the price of other items needed. Anyone have a ballpark figure on how much to list it on Facebook?
Thanks again.
Rod
 
........... My intent is to get it running and then paint it........
My suggestion is to first get it running. There's a lot that you can never discover about the tractor until it is running (and run it for a while). Things that will show up after several hours of use, like leaks, problems with starting after it gets hot, etc. There's things that will need to be addressed that if painted first will require a do-over because it will compromise the paint job. JMHO Stan
 
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