I'll try to be as detailed as possible here. I have a farmall H that is cranking way too slow, so slow that it will not start. I have narrowed it down to the starter, I believe. I tried to start the tractor by sending voltage directly to the starter via jumper cables, and I get the same result, painfully slow cranking, even for a 6 volt starter. And yes, I'm using 12 volts to jump it, but only for a few seconds at a time, and letting it cool between tries. Is my starter toast, or should I look elsewhere?