Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 322Get this manual
5Check shift link rod adjustment as follows: aPlace outboard shift lever in "F" (Forward) position Propeller should not rotate in COUNTERCLOCKWISE directionIf propeller does rotate COUNTERCLOCKWISE, length of shift link rod must be reduced and Step "a" repeatedbPlace outboard shift lever inN" (Neutral) positionPropeller should rotate freely without drag If not, length of shift link rod must be increased and Steps "a" and "b" repeated cWhile rotating propeller, place outboard shift lever in "R" (Reverse) positionIf propeller can be rotated in either direction, length of shift link rod must be increased and Steps "a" thru "c" repeated dPlace outboard shift lever in "N" (Neutral) position Propeller should turn freely without dragIf not, length of shift link rod must be decreased and Steps "a" thru "d" repeated 3Place end of throttle cable guide (a) over peg of