1998 Johnson Evinrude "EC" 9.9 thru 30 HP 2-Cylinder Outboards Service Manual, Page 45Get this manual
r:ru 2Tiller the full SLOW position speed knob fully counterModelsTurn the idle clockwise to 3Start the engine and allow it to reach normal operating temperature4When speed is reduced, engine must idle at 700 25 RPM in FORWARD gearStop the engine
5Adjust the idle speed screw to change idle speed
6Tiller ModelsRemove throttle cable bracket screwAdjust the throttle cable bracket to provide slight preload against the idle speed screw when the Twist-Grip is held at the full SLOW position7Run engine in gear at, or near, full throttle for one minuteQuickly reduce speed to SLOW (700-800 RPM) and shift into NEUTRALEngine should continue to run smoothly8If engine stalls or backfires, the idle mixture is too leanRefer to Carburetor Adjustment, Section 2Shift Lever Detent Adjustment 1Rotate propeller shaft and move the shift lever to NEUTRAL position