1976 15hp Evinrude running rough

I have a 1976 evinrude 15hp (15604A) motor that just recently started running rough, sounds like it is not running on both cylinders and not having full power under load. When running and I pull the lower cylinder plug wire it runs a little rougher and when I pull the top cylinder plug wire is runs very rough and dies out. I switched the ignition coils around and pulled the plug wires again one at a time and it does the same thing. I cleaned and set the gap on the points to .020 and still not running right. Any help with a solution here is appreciated.

Replace points and condensors with new oem products. That ignition is hard on points and condensors. You should also switch to NGK plugs.

Pandora, are you aware that motor (1974-76) was death on spark plugs from the day they came new out of the box?

Just installed a new set of NGK B7HS spark plugs. I suspected that it would be the points and condensers, I will try that. Thanks for the input.