6 volt starting sytems absolutely MUST have clean, tight connections everywhere. Start with both battery cable terminals- - - -remove the terminals and give the battery posts a thorough scrubbing with a wire brush, then get yourself a "battery terminal cleaner" with a round brush the right size to fit inside the cable ends, and scrub them bright and shiny. Bolt everything back together tightly, and spread a little wheel bearing grease on the terminals to prevent corrosion. Do the disconnect, clean, and reinstall procedure on every cable connection between the battery and the starter, on both hot and ground sides. Voltage drop between the terminals should be no more than 1/10 volt for each connection. With the starter running, the battery terminal voltage should not drop below approximately 4.5 volts. The ammeter needle should go about halfway between center and the + side immediately after starting, and slowly move back toward center after several miles of driving. If it's staying centered even after starting, you've got generator or regulator problems.
Jerry
