Mercury Mariner 4, 5, and 6HP 4-Stroke Factory Service Manual, Page 94Get this manual
CARBURETOR
Carburetor Adjustments
Idle SpeedInitial Setting Pilot (Idle Mixture) Screw
1Turn pilot mixture screw in (clockwise) until lightly seated than back out to an initial setting of 12 turns2Start engine and run at slowidle speed in forward gearTurn pilot screw in until engine starts to lose rpm, than back out 14 turn and adjust for best performance
NOTE: Allow time for engine to stabilize between adjustmentsDO NOT adjust leaner than necessary to attain reasonably smooth idleIf the engine hesitates on acceleration, readjust the pilot screw