Merc 115 Mid 70's Electrical Miss

[Booyah Bass]

Mid 70's Mercury 115/1150 Thunderbolt. I can run it with the warm up lever after starting but it has a electrical miss. When I idle it down to put it in gear the RPM's fluctuate and there is an electrical miss also and the engine will die. I can restart it but it will do the same thing. Would the rectofier cause an electrical miss? I have run it at the house in the dark to check and see if I have a wire arching somewhere? Any advise appreciated.