I receive many emails about starting problems with 6 volt cars. Here is a standard reply that may be interesting to some members. Some owners rip out the 6 volt stuff and install 12 volt system with the notion that 12 volt is better. The 6 volt systems were fine when the cars were new and they started fine. Converting to 12 volts creates many headaches.
The 6 volt stater had a problem with the stator insulation swelling up and when there is even the slightest wear on the bushings the armature will touch the stator and that physical contact robs the power. If you install new bushings in the starter it will normally solve the problems . You can also look at the inside stator and see rub marks, you can file these down a little on the armature also , but sometimes it is the insulation that is rubbing The 4 pole starter can be made by using a 6 volt Pontiac starter and install everything from the Stude starter and you will have to drill a hole for the locating pin. This is really not necesarry. An original starter should work fine. The Pontiac starters are rare and expensive. You can not install additional poles in yours as far as I know. An other problem is that the battery cable is of a too light a gauge wire. You can buy heavy #1 or #0 gauge battery cables at a tractor supply. Autozone and Napa also have these. On my own 6 volt cars I installed a ground cable from the positive of the battery ( these cars are using the positive post of the battery as ground and the negative feeds the car) directly to one of the bolts that hold the starter in. That really help cutting down the resistance. Any comments, corrections or suggestions are invited.