And no single word about it in Service manual....Most motors since the mid 70's only have fixed jets ... no adjustment for mixture at all.
Yes, I did as you write, idle speed on water is ok, however the run in idle is not so smooth as I expected. Therefore I thought to play with each carb individually.Idle speed and idle mixture are two entirely different things. If you have an OEM shop manual, it will surely tell you how to adjust the idle speed. Try the 'idle set screw' if your motor is similar to the picture.