1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 125Get this manual
CARBURETOR
TILLER HANDLE MODELS (SIDE SHIFT SHOWN) 1Turn idle speed screw counterclockwise until screw is not touching throttle shaft arm
a-Idle Speed Screw b-Throttle Shaft Arm 2Install throttle linkage on pulley and throttle barrel
a-Throttle Linkage b-Throttle Barrel c-Pulley 3Check to make sure throttle linkage is has free movement between throttle barrel and pulley