Here's some information of reverse charging of a lead acid battery:
Battery Myth | Can a Battery
....So let me restate: The only way for a battery that has a positive charge, to reverse itself, is for the battery to be completely discharged, and then reversed charged. We have seen this happen a couple of times, and it would be considered the more common of these rare situations.
For all intents and purposes, the battery will be ruined. You could technically charge it up, negatively, and continue to use it, but your plates are designed with the positive plates being lead dioxide, and the negative being composed of a sponge lead, which would now be reversed. Because the reversed battery is no longer formatted correctly, it will only work to a limited degree.....
Sounds like a new battery might be a good choice in the near future.
I would get a new battery as soon as possible before that one short's out inside and burn's stuff up.the plates will melt together and short out when your a mile away from anything to put the fire out. to me it's just not worth taking a chance like that over a $50 battery
Check the manual it might be correct. I don't know that make of tractor but some autos are hooked up that way.
I'm not that familiar with kubotas but some older JDs have a positive ground. Check it out first.
Not to hijack but, I once installed a pair of new C cells in something or other and the device did no work so using my volt meter I checked the cells and discovered that one cell was somehow built reverse. Never did figure out how that could happen.