Cranks but won't start. Unplug ground at field spade on Alternator and it starts?

From what I read searching internet is when cap melts in middle could be gap between cap center and rotor or center button broke off. Center button in cap some times breaks off if cap not installed carefully.

Weeks back I ordered cap and rotor and rotor was wrong so only replaced cap. Was cap a mis match for old rotor?

But hey all this cleaning electrical connections ect I have 11 volts at coil when I crank it over. So effort not a total flop right??