Mercury Mariner 8/9.9HP 4-Stroke Factory Service Manual, Page 76Get this manual
Full Throttle Link Rod Adjustment 1Tiller Handle Models: Place outboard in the "full throttle" forward gear positionRemote Control Models: Disconnect the remote control cable from the throttle armHold the throttle arm in "full throttle" position
Idle Speed Initial Setting
NOTE: Before adjusting idle speed, make the full throttle link rod adjustmentSee procedure precedingTILLER HANDLE MODELS 1Place throttle twist grip to neutralidle position2Back the idle speed screw off of the throttle lever so idle speed screw does not touch lever
aIdle Speed ScrewThrottle Lever
3Check for link rod free playThere should be free play between throttle link rod and throttle cam stud