1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 70Get this manual
Idle Adjustment 1With engine in water, connect electrical harness and fuel line to engineStart engine and allow to warm up2Properly adjust carburetor low speed mixture screwsRefer to "Carburetor Adjustments" section 3A3Holding throttle arm at idle position (throttle cable barrel removed from barrel retainer), adjust idle timing screw to attain an engine idle RPM of 650-700 RPM in "Forward" gearTighten locknut and turn off engine
Throttle Cable Installation
1With end of throttle cable connected to throttle lever, hold throttle lever against throttle stopAdjust throttle cable barrel to slip into barrel retainer on cable anchor bracket with very light preload of throttle lever against throttle stopLock barrel in placeIMPORTANT: Excessive preload on throttle cable will cause difficulty when shifting from forward to neutral(Readjust throttle cable barrel, if necessary 2Check preload on throttle cable by placing thin piece of paper between throttle stop screw and stopPreload is correct when paper can be removed without tearing, but has some drag on itReadjust throttle cable barrel, if necessary 3Reinstall sound box cover