Honda BF9.9A-BF15A Outboard Motors Shop Manual., Page 34Get this manual
2) After the engine speed has stabilized turn and adjust the throttle stop screw to achieve the specified idle speedSpecified idle speed (Shift lever in neutral)
50 min-I (rpm)
Pilot screw
I the pilot screw setting needs adjustment:Turn the pilot screw in or out until the engine runs at the highest idle rpmI the pilot screw has been removed and replaced, start with an initial setting from the fully closed position listed in the table below, Standard pilot screw setting
BF15A: 1-518 turns out BF9.9A: 2-314 turns out
2) Turn the throttle stop screw to obtain the specified idle
THROTTLE CABLE
ILoosen the lock nut and 12 mm hexbolt at the adjusting plate2) Set the throttle grip to the "SLOWtt position, and hold the throttle lever in the fully closed positionNOTE Be sure the throttle damper is released before adjusting cable free play