Bad Starter or Starter Solenoid?

The large wire is 12 volt power. The other wire, usually blue is switched ignition. I know what they are saying about the mini starters and changing the contacts, but if the solenoid is indeed engaging as it sounds like it is, the contacts are there and the motor is not spinning. Start with the basics. A 12 volt test light and 5 minutes and you will know what you need.