Bayou 220 electrical
 

With solenoid not jumpered - no lights but pull starts fine
With solenoid jumpered - all lights / switches work and starter makes solenoid click.
What is going on?

Have you just fitted the solenoid? Seems like it is fitted backwards, The big terminals have M for starter motor and B for battery next to them, check you got this right. The fact that it still didn't spin the starter indicates a faulty starter motor too. That is probably why someone tried changing the solenoid.

I took those as B and W.... which are labels on the schematic. Lemme try it the other way.

You were correct. Interestingly enough the M is upside down. Awesome... coupled with the schematic showing Ws- I had it wired wrong.

I will have to look at replacing / rebuilding the starter.

thanks for your assistance!