new to me 48

[brianmacb]

Alright, so I just picked the cub up yesterday. The kid had a new 6v battery in it but it won't crank from the starter, he said the starter solenoid was bad. I replaced it and it barely cranked and quit after maybe 3 revolutions. Before i replaced the solenoid i should say that it was being hand started and fired up pretty quick doing this. I drove 10 hours home with the cub and it fired right up to get it off the trailer, however I shut it off after that and when I went to start it again it would not start. I left it sit until morning, came out and it started right up, I rode it around for 30min or so, came home and parked it and came out to start it for a neighbor who came to look at it and no matter how many times i hand cranked it, it would not start.

To this point I have hooked a 12v to a ground and the starter, it fired right up doing this but would die immediately after taking the positive cable off the starter. I tried to start it twice this way, died both times after removing the cable from the starter. I went and got a brand new battery put it in thinking the battery was just dead to why it wouldn't crank with the starter, well i got a charged one from napa, put it in and nothing. The battery is not registering on the ammeter when the ignition switch is on either if it is supposed to or if its just when its running. I don't recall if it even registered when it was running, didn't pay too much attention I guess. The only thing I can see that isn't factory in the system is a 6v coil that replaced the dead magneto.
Any help will be greatly appreciated, I am new to the cub as well as inexperienced with 6v systems.

[bythepond88]

Sounds like there is a problem with the positive battery cable. Check all connections for the cable, including pulling the cable off the battery and cleaning the post and the clamp on the end of the cable, no matter how clean it looks from the outside. I had exactly the same symptoms as you: started and ran fine while jumping it, but as soon as I removed the positive cable, she died. The battery post and clamp looked clean, but when I pulled it off, there was black build up on the inside of the clamp and on the battery post. Cleaned those off, and problem solved.

Also check the connection at other end of the cable and make sure it is shiny bright.

[brianmacb]

I just went to napa and got a new coil and new positive/ ground cables. Hopefully this will work, I will post an update after I get back home from town.

I will try and post some photos also depending how I feel about the cub if it starts here in a bit. I was all excited to get one with a few attachments but has done nothing but aggravate me since I got home with it, so the photos are pending for this evening.

[Bill Hudson]

I was all excited to get one with a few attachments but has done nothing but aggravate me since I got home ...

Welcome to the club. 67 year old tractor, you have got to expect a few problems. I'm a '42 model and I don't purr like I used to either.

Bill

[brianmacb]

I gotta say, no matter how rough and calloused my hand are from work that hand crank did a number on my hands. Got smart after the first blister and put a pipe over the end of it.

[brianmacb]

Ok, so now I'm really stumped and need some advice. So, I got the new cable on and put it exactly how I took it off. It arced out to where it would melt the lead on the terminal, I looked at a photo I have where the positive is the ground and the negative is what runs to the starter so I switched it around from where it was and its doing the same thing( arcing out). What is going on here?

[CapeCodCubs]

Cubs are positive grounded. I was going mention this a lot earlier.

[brianmacb]

Cubs are positive grounded. I was going mention this a lot earlier.

I got it with it being hooked up negative ground, so me not even thinking about it tried to hook the new wires and new battery up the same way, arced out. So I switched it back to a positive ground, same problem with it arcing out. Don't have a 12v laying around to test it in there.
I'm wondering why it started with the hand crank yesterday and everything looks to be original except the 6v coil replacing the magneto. From what I've read, converting to a 12v won't allow you to use the hand crank anymore? This cub has me stumped and I'm at my max in knowing 6v systems

[staninlowerAL]

Welcome to the club. 67 year old tractor, you have got to expect a few problems. I'm a '42 model and I don't purr like I used to either. Bill

I agree with Bill. I don't purr like I used to either. You probably have several things going on: 1. the arcing when you connect the battery probably means the VR or Cutout points are stuck or burned closed thus providing a direct path to ground and hence the arcing. 2. The fact that you have started it an now it will not start with the new coil could mean the points are either not providing the path to ground when you try to crank it OR they may be fried from your attempts with the 12V battery. 3. In any case, you are going to have to be able to trace the path for electricity from the battery to the distributor and understand what it is supposed to be doing at each connection along the way. Check the links at the top of this page for SERVICE/OWNERS/PARTS Manuals for your tractor and the Blue Ribbon Service Manuals for all the information that you will need. The ground path is the tractor frame and bolted/screwed on parts so these must be bright clean, no rust for optimum performance. If your battery ground is connected to the floor pan/battery box, try moving it to a transmission cover bolt. BTW, the points gap for the mag is .013, not .020 just because you have an external coil. There are some internal parts (rotor and pinion gear) in the distributor that might have to checked as well so if you get into that, be sure it is timed correctly when you reassemble it.

[Scrivet]

I just went to napa and got a new coil and new positive/ ground cables. ...........

Are the new cables heavy enough for 6V? Most of the off the shelf cables (usually 4 gauge) are for 12V and are a little wimpy for 6V (needs 2 or even better 0 gauge). This is not your biggest problem at present but something that will eventually work it's way to the top as you eliminate other issues.

[tmays]

Yes you can hand crank a 12V Cub as long as battery is strong enough to provide spark

[brianmacb]

The cables are 1 gauge, plenty for a 6v system. I'm thinking someone tried to do a cheap 12v conversion on it at one point in time. I found a 6v wiring diagram and none of the wires on the cub are where they should be according to it. I'll have to pull the hood off to check the top of the voltage regulator also. I found a new distributer/magneto setup online which would get rid of the 6v coil on there now.
Right now the wiring leads me to believe it is a cheap 12v conversion. Just a matter of what's ruined and needs replaced I guess. I won't have time to mess with it again until this weekend maybe.
If it is a cheap 12v conversion what could be ruined as a result of this? I know right now as it sits it won't work as a 6v the way it's arcing out and putting a 12v to the starter I'm not getting any spark now. Case IH quoted 240 for a reman generator and the magneto/distributer I found online was 250, not really wanting to dump a lot more money into this to get it running. So if anyone has experienced this situation before and has a good idea of the root cause and solution I'm all ears at this point.

[Eugene]

Starter needs to be repaired.

What makes you think the electrical system has been converted to 12 volts?

A solenoid is an electrical mechanical device. The 1948 Cub didn't have one. The 48 Cub's starter has/had a switch activated by a pull type lever.

Since the tractor runs, do not purchase any parts until you figure out why it will not start using the 6 volt battery. The starter on a 48 Cub is/was 6 volts and will operate on 12 volts. Most likely would not have been changed to a 12 volt starter if someone put a 12 volt generator/alternator on the tractor.

Does the tractor have a magneto ignition system? Probably not a magneto since the tractor dies when you disconnect the battery. The operator's manual has photos of a magneto and a battery powered ignition system.

Did someone mention the probable cause of the arc when you try to connect a cable to the battery? I believe so.

[staninlowerAL]

Case IH quoted 240 for a reman generator and the magneto/distributer I found online was 250,...So if anyone has experienced this situation before and has a good idea of the root cause and solution I'm all ears at this point.

If you are looking for a quick fix, most likely you won't find one but an upgrade to a 12v alternator (preferably one wire) can be done for about $100 or so for parts. For a step by step "HOW TO", check out the electrical threads on the HOW TO forum. viewforum.php?f=140 Not sure about your "online magneto/distributor" but you should be able to find a battery/distributor setup for another $100 or so which will totally eliminate the magneto, just be sure you get ALL THE PARTS as nothing but the cap, points and maybe condenser will interchange. OR you can diagnose and fix what is wrong with the system you have. The Service manual http://www.farmallcub.com/[ Sorry, direct links to manual section is not allowed. ]/downloa ... -27-55.pdf is a good place to start. It can be done. I have a 49 FCUB that uses a 12v battery/coil with internal resistor, BUT simply changing to 12v will not solve other problems, maybe only mask them. Things like low compression, improperly adjusted valve lash, poor grounds, wiring that should be replaced, etc. Any machine that is more than 65 years old is going to need some TLC. You get the picture. GOOD LUCK

[brianmacb]

Starter needs to be repaired.

What makes you think the electrical system has been converted to 12 volts?

A solenoid is an electrical mechanical device. The 1948 Cub didn't have one. The 48 Cub's starter has/had a switch activated by a pull type lever.

Since the tractor runs, do not purchase any parts until you figure out why it will not start using the 6 volt battery. The starter on a 48 Cub is/was 6 volts and will operate on 12 volts. Most likely would not have been changed to a 12 volt starter if someone put a 12 volt generator/alternator on the tractor.

Does the tractor have a magneto ignition system? Probably not a magneto since the tractor dies when you disconnect the battery. The operator's manual has photos of a magneto and a battery powered ignition system.

Did someone mention the probable cause of the arc when you try to connect a cable to the battery? I believe so.

Why does the starter need repaired? It works as it should when a current is put to it. The solenoid I was talking about is the exact same one that came on the tractor when new, just a replacement I got from the implement.
As for why I believe someone tried to do a 12v hack job is because it was hooked as a negative ground and from the wiring diagram I found for the cub the wires are switched in a couple different places. Could they have just wired it wrong? Possibly, I don't know and went out of state again for work so I can't dig into it further until I get back home next week.
From what I can tell the original generator is on it, the points system with the magneto is there but the magneto was bypassed with a 6v coil that has a wire(neg) coming from the voltage reg and the positive going to I'm assuming a ground on the side of the ignition system.
There are three wires coming from the switch(solenoid) on top of the starter, one goes to the what should be the fuse side of the ammeter. The second wire goes from the starter to a switch that is supposed to be the ignition switch, the third was the positive side of the battery when I got it.
The battery cables were replaced by me to a correct positive ground setup after I realized it was negative ground before to find that it arced out as a positive and negative ground.
I don't know enough about 6v and points systems to go further without assistance. Everything old enough I've had had already been switched before I got it.
Either way, I talked to the local case IH implement and the service adviser told me he knows all about them and to bring it in and he'll tell me what the problem is and get me the right parts for a repair.
I'm very mechanically inclined but, dealing with a new system I've never messed with before it's going to take me a bit to get used to it. I'll keep you posted on what they tell me when I get time to run it down there after I get back home.