8volt battery

[inairam]

There appears to have been a great deal of thought and effort put into getting 8-volt batteries to work that may be been better spent fixing why the 6-volt system was not charging/ starting. 6 volts works fine on a well timed and turned up cub.

[chief]

I got my 1951 cub in 2009 and have been running it on a 12 volt battery all these years with no problems at all,
all it does is spins the motor faster and starts as soon as I pull the lever, maybe I'm just lucky

[Matt Kirsch]

Exactly, you need to have the knowledge and capability to build something like that. How many do?

[SONNY]

8-v will quickly take out 6-v light bulbs,---(don't ask how I know)! thanks; sonny

[Papacub]

What would change to make it necessary to polarize the generator?

[JohnMihevic]

I don’t know what would change that would make it necessary to polarize the generator. I am assuming you are still using positive ground.
Since you have a ’58 Cub I believe it has a voltage regulator. You will not charge an 8V battery on a system that has a voltage regulator like your Cub.

My friends “Model T” works O.K. and charges his 8V battery because the “T” has a cut out relay like the early Cubs and the “3 brush” generator acts like a current source so it’s happy putting out current at 6V or 8V.

See my post earlier in this thread if you want to see how to charge your 8V battery using a 12V charger. The only parts needed are 8 diodes Newark Part #76K5515 and a Terminal Strip Newark Part # 28F719. The diodes are $0.33 a piece and the strip is $8.30.

A solution for your light bulbs is to put resistors in series with your light bulbs to drop 2V from 8V to 6V. The lights on my Cub each draw about 4 Amps. A 0.5 ohm 10W resistor In series with each bulb would reduce the voltage to about 6V. The Newark Part # for the resistor is 33M7545. Cost is $0.90 a piece.

John M.

[Papacub]

Well after a little tinkering this weekend it looks like the points need replaced....A big thank you to all the helpful replies, ordered some new points from tm tractor supply and hopefully by next weekend will be ready to plow! Thanks everybody!

[Glen]

Hi,
Glad you found that, hopefully that will make it run better.
Checking the timing is a good idea, they don't run good if the timing is wrong. You need a timing light to check it.
Here is a page from the Cub service manual showing the timing marks, set the timing to mark number 1 in the pic, when the engine is running at slow idle speed, supposed to be 475 RPM normally. I think the manual said somewhere to check the timing at a little slower RPM, to be sure the advance was not advancing the timing. I've not seen that it advances at 475 RPM.
They are talking about another subject on the right side of the page.

http://www.farmallcub.info/manuals/gss- ... 001-43.jpg

[eiebe]

I put an 8v in my cub and had the regulator adjusted to let it charge, my cub ran fine just slow cranking in Sub zero weather. Haven't had a problem yet. Just my 2¢