circuit breaker
 

I have a 350 mag that is not starting. I would try to turn it over and just hear a click but now I dont even hear the click. The red button 50 amp circuit breaker is out and can not be pushed in, would this be a cause to the issue?
I have put a new starter in.
Thanks.

If you can't put in the breaker, then it's probably not "popped". If it clicked, then it's not the breaker.
First off, you have confirmed a good battery right? Put a DC volt meter on it. Hook it up to a charger if questionable, or you don't have a meter. If good then make sure you have a good connection's to the starter. Check voltage on the large terminal to ensure a good connection there, it will have a large red wire going directly to the battery or battery switch. Report your finding and will go from there.

+1 Sounds like a bad connection or dirty connection to me as well....

or a bad solenoid right next to the breaker. jump that first...

Thanks for the help, good info there. Ended up cleaning all the electrical connections with emery clothe, fully charged the battery and it started up. Thanks again