Fist off I don't know any thing about tractors just bought a 641 workmaster.is there any common problems with them that I should look for? Also it has the 6 volt pos.ground.I would like to change it to 12 volt,what is the pros and cons to this and also I am confused as to the pos.ground set up (never had anything but neg.ground)would also like to change to neg ground.what would be the best route to do both thanks for any help.PS to show you how lost I am the battery ran down and I ask a guy how do you charge the battery since it's pos.ground he said to put the pos (red)cable on the neg post of the battery and the neg (black) cable on the pos post and I had to buy a 6 volt charger so I hook it up and it said cables hooked up wrong luckily I found this site and got it charged up thanks for that