Solenoid or something else??

[Russell Reay]

I just installed this solenoid acquired from Amazon. Push button switch is NAPA for a 1948 Ford. I believe this is an original starter switch, not a repop. I turned the copper strip upside down so it makes good contact (I think) all the time. When pushing the button, the starter engages and the engine turns over, but it sounds like the teeth are not engaging all the way. There is a wicked, nasty chatter which in the old days would be instantly diagnosed as a low battery or bad solenoid. In my case the battery is fully charged. If I take the solenoid out of the circuit, remove the starter switch, and touch the neg cable to the big copper lug on top the starter, it turns over with vigor just the way it should. The wires from the terminal box to the push button to the solenoid are 12 and 14 ga. It's hard for me to think that those small wires are the problem, but maybe. If it is just a poor quality solenoid, I'll replace it with a Ford tractor one from NAPA. Recommendations please