My ex was riding it and bouncing off the rev limiter and it just shut off. Blown fuse in the starter solenoid. Changed the fuse and nothing so I changed the CDI and nothing so I changed the starter solenoid and battery still nothing. No click when you hit the starter and won't pull start. 15 hours on this thing and ridden by little kids until she got on it and I don't know what else to check. Looked at all the switches and wiring harness and all seems good. Any thoughts?

 

I would start with pulling the plug and use the pull start to see if you have spark at the plug (lay plug on head). Make sure the key and or kill switch is on.

 

Welcome to the forums.
On the Lt80's there is a circiut breaker under the right rear fender (push the red dot).
Sorry I don't know if your Z90 has such a thing.
It does sound similiar tho.