Winner winner chicken dinnerOn the 4 stroke, a lot of times the higher required amp rating is because the computer demands the power to run the engine. One downfall to the more modern engine is that they need a constant battery source in order for their computers to run all the sensors, etc. not 100%, but I know a lot of motors do not generate enough juice at idle/low speed and actually feed off the battery. Of coarse once they get into the higher rpm range they generate an excess which in turn charges the battery.
My "real world"experiences with this have been on 150 optimaxs, new 150 merc 4 strokes, yamaha 225 four strokes, 60 hp merc efi 4 stroke, etc.