Bolens Riding Mower Won't Key Start?

I have a 38" cut Bolens riding mower with 15.5 hp that does nothing. I replaced the battery, solenoid, carb, fuel lines and filter, air filter, spark plug, and the 20amp fuse. All this and I get not a sound or a movement when I turn the key. However I can bridge the solenoid and jump it. Any idea on what's going on? I am not sure if I need a new ignition or a starter or something else?