Jump starting an 8-volt system with a 12- volt system

My "M" has an 8-volt system. What is the proper way to jumpstart this system with a 12 volt system. Also, how do I charge this system? Thanks a million

I'll almost bet its not a true 8 volt system just an 8 volt battery. 8 volt battery's at best are a band aid fix for a problem 6 volt system. To jump start it you hook it up + to + and - to - but not right to the battery. You hook it up to the frame and to the starter post so as to never have 12 volts going into the 8 volt battery or you could in fact blow that 8 volt battery up. Also 8 volt battery's are next to impossible to charge because you can not ind a charger that will do so
Hobby farm

Doesnt matter where you hook it up. The cables are going to run it back to the battery however you hook it. Ive done it many times, just hook it up to the battery just like anything else but dont leave them on there very long because it will boil the battery. Hook up, get on the tractor and start. Then unhook right away.
But as far as hooking on the starter or battery it will go the battery either way. Infact a 6v system has heavier cables then a 12v because it carries more amps. Volt x amps = watts so if you have 6v it takes more amps, thus heavier cable. 12 takes less amps to do the same work, so you can use lighter cables. One thing we were taught in school was that most starting problems comes from poor cables, cable ends, and connection. Found this to be true more times then not.
hope this helps.

Sorry but your wrong on it going back to the battery. If you hook one end to the frame and the other to the starter post there is no way in the world that it will go back to the battery unless you also push the starter button which if hooked like I said will not be needed. Hooking 12 volts to a 6 volt or 8 volt battery can in fact cause the battery to blow up BTDT and seen it happen way to many times. Be safe not dumb

I agree with Old. If you ground it to the frame and touch it directly to the starter post you won't risk blowing up the battery, which I have done.

Oh so your jumping it, just like you would with a screw driver. Heard of many getting killed that way. Not Smart. rather take my chances on boiling over the battery.

Guess you don't know much about zap-u-trons then. Very very hard to get hurt by 12 volts or 6 volts or 8 volts unless you do things when you hot and sweaty. Plus if your holding on the the plastic that is on jump cables there is not way to get shocked. Under normal condition the average human has to has at least 32 volts to be shocked. I.E. normal humans have a resistance high enough to keep from being shocked with less then 32 volts but go over 32 volts and yes you get shocked. But if you want to think that way I can kill you with a D cell flash light battery if done right

Not a pretty site when a battery blows is it?? I know of more then one person that is blind because of having a battery blow up in there face

Im talking about it being in gear and starting it with a screwdriver or jumping it with jumper cables. I know we all think that were smarter then that but in the middle of working we do forget things. This accident has happened many times when shorting out the starter. Its not an accdient that IH put the starters in the middle of the tractors where their hard to get at, like on 66 series. They were staying one step ahead of the guys who didnt take the time to get on the seat to start. Theres different ways to start a dead tractor but just be safe either way you do it.

Well of course before you ever try to jump start it in any way you check and double check that its out of gear and even better have some one on it holding the clutch pedal down also. I always park my tractor out of gear and I work on some many of them that I start most with out being on the seat and having to do funny things to make them run. But I also do not buy many tractor that run when I get them so I have learned how to make them run when most people can not get them to run. But I have also been working on old dead iron for decades and enjoy bring one back from the dead
Hobby farm

Yeah the old ones are fun and simple. I work for an auction company and have to get them running. we also do some repoing for the banks so we get in to some pickles and have to have it all out in one day, takes some doing sometimes.

Thanks so much for all of the battery help. I like the thought about this actually being a 6 volt system. How can I know for sure?

8-volt chargers are hard to find today---but back in the '60s & 70s there were lots of chargers which had 6-8-12 volt switches. I've got 2 or 3--most were made for outfits like Farm & Fleet-Tractor Supply & that type of supplier. I believe they were made by Schauer--they actually put good transformers & rectifiers in the chargers back then. A guy brought a John Deere "booster" charger by the other day which was little better than junk. For the booster, the instructions on the case said "2 seconds on--220 seconds off[cooling]. This was a 2-year old charger & probably cost the guy 40 or 50 bucks.

Get rid of the 8 volt battery!!! Go to a 12 volt battery with a one wire alt or go back to 6 volt battery with heavy cables. I prefer the 12 volt neg. ground/alt. myself. Armand

(quoted from post at 04:05:47 12/28/08) Thanks so much for all of the battery help. I like the thought about this actually being a 6 volt system. How can I know for sure?

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There are only three things for sure in life: Death, taxes, and your tractor having a 6 volt system.

There is no such thing as an 8 Volt system. Again, 8 Volt batteries are a bandaid for a misbehaving 6 Volt system.

Battery cables become corroded, starters wear. The 8 Volt battery makes the engine roll over better in spite of those problems.

Replace your battery cables with new 0 gauge. Make sure all connections are clean and shiny before tightening the bolts down.

Get the ignition tuned up and timed properly. If you've got any nagging problems with the carburetor, get them taken care of too. Learn what your tractor needs to start, full choke, a quick blip, no choke....

The tractors don't roll over very fast on 6V, but they don't need to. They were designed to start on a hand crank.

If you jump it with one cable attached direct to the starter terminal/stud (attach it first) then jump the other lead to a good clean frame ground close to the starter, THAT ENERGIZES AND DRIVES THE STARTER ONLY (provided starter switch isnt engaged) AND WILL NOT BACKFEED 12 VOLTS UP TO THE BATTERY (OLD, AS USUAL, IS CORRECT) which could cause it to blow up so thats how I suggest it be jump started. So long as the battery has enough energy to provide a spark (unless its a mag which dont need battery energy) and all else is correct, she ought to start.

THE WORST AND MOST DANGEROUS way to jump would be by attaching the cables right at the battery top cuz thats where explosive gasses may be exiting and you will create a spark when the last cable is atatched. Thats why they tell you to make the last jump connection at frame ground somewhere far away from the battery

MAKE SURE ITS OUT OF GEAR DUHHHHHHHHHH

JUMP AT THE CORRECT POLARITY + to + and - to -

Im NOT a fan of the 8 volt band aid approach, I suggest EITHER use 00 gauge battery n starter n ground cables and the biggest heaviest highest rated 6 volt battery that will fit in place or else convert to the standard 12 volt system.

Depending on if its a Cutout Relay or a Voltage Regulator etc the tractor 6 volt genny can still charge an 8 volt battery if all is correct although it may not set the world on fire as far as the charge rate.

John T

Jumping directly to starter is right way BUT if you have ever had one start up in gear with you standing beside it you get a little leary of that method. 999 times out of 1000 I double check to be sure it is out of gear but that one time you forget can kill you. Had a nieghbor start a ford in gear from ground few year ago and tractor pushed him through back wall of shed, DOA.

I bought an M with an 8 volt positive ground system on it. It worked but I was always tweaking the regulator to get it to charge at the correct rate. After the 8 volt battery went bad I converted it to 12 volt negative ground. That way if I ever had any problems and had to jump start it I could do it with my pickup. So far it starts and charges great. I have no regrets converting it over. By the way I had the generator rewound. A generator set up in good condition should work good and be trouble free for years.