suck, squeeze...bang, blow.....to get those 4 to work together when there is a problem can be very tough. Lots of good solid info here on a solution. I say get rid of the points and drop an hei into both engines, way easier system to use and alot less trouble than figuring out if the shafts worn on the old one. the slightest pin hole in a fuelpump diaphram can cause some of symptoms your having. might be a good idea to have fuel pressure guages after the pump and before the carb on both motors, possibly even adding an electric pump incase of a problem while on the water. please keep us updated.