Super M Battery

Farmall M, Super M, 400, 450 & 560 Tractors, 1939-1963

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Jason (IL)
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Super M Battery

Postby Jason (IL) » Sat Aug 11, 2012 12:35 pm

My super m has such high compression a 6 volt battery could hardly get it over the bump. So I was told by a good friend with over 50 tractors to put an 8 volt battery in it. So I did and what a difference it made. But now my question is? Do I need to do anything to my current 6 volt charging system, will the 8 volt charge ok on this system.

I was thinking maybe ground the field post on the generator or something may be needed. So I did and noticed a big difference in where the amp meter runs.


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Re: Super M Battery

Postby danovercash » Sun Aug 12, 2012 10:15 pm

Jason, Were you sure all parts of the starting circuit were working 100%? Starter contacts may need to be cleaned/replaced. You will need to set the voltage regulator to put out 9 volts, and then you run the risk of blowing out any 6V. light on the tractor. BTDT with an old Chevy truck. Eventually had to change out the starter contacts, but could have just turned the bolt 180 deg. and reinstalled. A very good parts man once told me that if everything is as it should be 6V is all you need to start a 6V system, 8V is just a band-aid.
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Matt Kirsch
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Re: Super M Battery

Postby Matt Kirsch » Mon Aug 13, 2012 3:29 pm

Does the ammeter show a charge when the tractor is running?

If yes, then you are ok.

If no, then you need to do something.

What that "something" is, I'm not 100% positive. I vaguely recall that certain generators having a moveable 3rd brush that would change the output of the generator enough to charge an 8V battery. Which brush to move and how far, is the question.

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