1988-1992 Mercury Force 5HP Outboards Service Manual, Page 73Get this manual
3Turn adjusting screw (A) until throttle begins to openNOTE: Throttle shaft should start to move when roller aligns with short mark on throttle cam4Adjust idle speed(See SeCtion T) SADJUSTING IDLE MIXTURE (1990 and Newer)
IMPORTANT When adjusting the idle mixture screw, turn carefully and gentlyDo not force needle into seat1Turn idle mixture screw clockwise until it seats in the carburetor2345Open idle mixture screw one turn (counterclockwise)Start motor and allow to warm up to operating temperatureMove throttle lever to "SHIFT" positionShift motor into "FORWARD" gear and turn idle mixture screw clockwise (close) to the lowest "runable" settingSlowly turn idle mixture screw counterclockwise until motor speed decreases and operation becomes rough due to over rich mixture (note adjustment position)Slowly turn idle mixture screw clockwise: motor operation will become smooth and speed will increaseContinue turning idle mixture screw clockwise until motor speed slows or misfires from too lean mixtureTurn idle mixture screw to midpoint between settings noted in steps and 7LEAN CORRECT ADJUSTMENT MIDPOINTRICH