Verified answer

IDK if it is a solenoid or whatever, that tells the starter when to stop.

Or the swithch is bad. Don't remember if they started with a key or button.

You can re-arrange the wiring to cut the starter out when you are done using it. I did this on my Yamaha XS400.

I do know that bike is at least 23 years old, and was driven off road its entire life.

You should be happy that's the only thing wrong with it.