I've got an 84 750 Nighthawk S and had it in the shop for a month waiting for a new clutch. When I dropped it off it would start up first time every time.
After picking it up they said my battery was dead, so no biggie because it was under warranty I had it replaced. I charged the new battery, and the bike barely turns over once maybe twice. Could it be my starter is toast, or maybe the solenoid? The weird thing is I had no starting issues when I dropped it off.