1964 4000 Starter Problems

Tractor (4 cyl. gas) is still 6 volt. The batter I have is too small, but still works about 1/2 the time, if I keep trickle charger on it. Needed to roll it off this weekend. Had brush-hog attached (I know - I should have removed it!) and used starter to turn over engine and lift hog up so tractor would roll. Finally got hog up, but starter was smoking. Roller her off, cut for about 1 hour, then put her in shed for the night. Yesterday, hit the starter button with fully charged battery. She turned over once then stopped - now she only clicks when I hit the starter button. Before, even with low battery, it would "rump..... ...rump..... ..rump..... ." Now just 1 click then nothing.

Here are my questions:
1. Can I use jumper cables from its battery to its starter to determine if the starter is indeed the problem? If so, how? I started to go from Neg battery post to starter (it is a Pos. ground).

2. If I did fry the starter, is it likely that the local alternator shop can rebuild her?

And lastly, my next move will be a 12 volt conversion. Probably very soon!

Thanks!
Tommy D.

You have properly admonished yourself, so I will not add to that. Double check the solenoid as pulling that much current through contacts that are 35-40 years old is not good!!!!! !! PUT THE TRACTOR IN NEUTRAL AND BLOCK THE WHEELS. Once you have secured the tractor you can take a jumper cable and jump around the solenoid. General reference for the future: If you see smoke in the electrical system, it is not a good thing!!!