Suzuki 2003-2007 DF60 DF70 Outboard Motors Service Manual, Page 69Get this manual
ENGINE CONTROL SYSTEM
BY-PASS AIR SCREWPASSAGE Since the throttle valve is almost fully closed when idlingtrolling, the main flow of air necessary to maintain idlingtrolling speed passes through the by-pass air passageThe by-pass air screw controls the flow of air through the passage and provides means of partially adjusting the total amount of air necessary for idlingtrollingNOTE: See the page 2-14 for the by-pass air screw adjustment procedureIAC VALVEPASSAGE The IAC valve is linear solenoid plunger type mounted on the intake manifold (surge tank)Its purpose is to control the amount of intake air flowing from the IAC passageThe IAC valve is driven by the duty cycle signal from the ECM