Yamaha Outboard Motors Factory Service Manual F6 and F8, Page 110Get this manual
CONTROL SYSTEM ADJUSTING THE ENGINE IDLING SPEED NOTE:
Before adjusting the engine idling speed, make sure the throttle axle link is properly adjustedBefore adjusting the engine idling speed, warm-up the engineCorrect adjustment cannot be obtained when the engine is cold1Measure: Engine idling speed Out of specification Engine idling speed: 1,050 50 rmin Measuring steps: (1)Start the engine and allow it to warm up for several minutes(2)Attach the engine tachometer to the spark plug lead of the cylinder #1Engine tachometer: YU-8036-B90890-06760 (3)Measure the engine idling speed2Adjust: Engine idling speed Adjusting steps: (1)Turn in the pilot screw in direction until it is lightly seated(2)Turn out the pilot screw in direction to specified number of turnsPilot screw: 38 turns out (3)Turn the pilot screw in direction or b, no more than 38 of turn in either direction, until the engine idling speed is at its highest