On a 1990 60 hp VRO there is a brass plug/screw on the outside of each of the 3 carbs, are these just plugs or are they adjustments and if thet are adjustments what should they be turned out to?
15 is as WernerF says is for the idel mixture, and you use the screw to adjust a proper idle on all 3 carbs. When under load, fully turn in the screw and and then back it out 2 turns, then turn it in 1/4 of a turn a time and wait a bit, and when the motor starts to splutter just back it off a bit. Do this for all 3 to find the best idle for the motor.
