Re: 1976 evinrurude 70 hp
I agree with the thought of a cylinder dropping, but you could also have some junk in one or more of the high speed orifices. In fact, you could have both problems. Another thought is that the fuel pump may have a diaphragm that is on the way out.
One easy way to check the ignition, is to use an inductive timing light on each spark plug wire, one at a time. If you are dropping a cylinder entirely, or are getting erratic ignition, the timing light will let you know pretty quickly. If all is well there, I would start looking at fuel delivery issues.
