I just can't seem to figure this one out. 90 hp outboard, mercury, late 80's. I have replaced the trigger, the switch box, stator, plugs, wires, full tune up, and two new ignitions. It will run great when it is running - for days, then randonly not start. then a day or so later it starts right up and again a week or so from there out of the blue it wont start. No spark. Help!
