[Gompers]

If you’ve got a wire or remote starter switch to jump 12v from the battery to the solenoid you could see if that will spin it over.

If it turns over, that would rule out the solenoid, the solenoid ground, the solenoid load cables and, well pretty much everything aside from the wiring between the switch and the battery and the switch and the solenoid.

If that doesn’t spin over, its more likely the solenoid load cables, since you just replaced the solenoid and it’s unlikely to be the solenoid ground.

Edit:
Forgot to ask, does this tractor still have the safety switches installed/connected? That could be another place to look.