Originally Posted by
gmwillys
Welcome Steve!
The first thing I would turn to would be the battery cables. If you are running the 6 volt system, the cables have to be fairly healthy. The parts store, off the shelf cables are not adequate. The cables sold here on Kaiser's site are descent, but most of us will splurge and have semi truck style battery cables. Most truck shops or dealers can make you cables to your desired length. The other option is a welding supply store that sells welder leads in a custom length. These cables will give you little resistance, and can get your engine turning.
The next thing to check would be the starter itself. Often times the starter is taken off and tested/serviced by a starter rebuild shop, and they do not find any problems.
One of our members had the same problem as you are, and when they hop on, they can give you some more insight.