I have had an ongoing problem with getting my tractor started. Something with the PTO safety is getting hung up or something. Sometimes if I move the PTO handle forward and back, whatever is hung up or stuck is released and the tractor starts.

Any idea what it is?

Your going to have to follow the linkage from the handle downwards and look for an electrical, safety switch. It'll likely have a push button that goes in and out as you move the handle. 
 
My guess is a somewhat bad connection inside the switch. 
Usually, a good dousing of Liquid Wrench (not so much WD40)
will clean up the contacts. 
 
That or replace the switch.. 

Thank you! I will give it a try.