Patent ID: 6612882
Filing Date: 2003-09-02
Classification: F02B,F02D

Abstract:
A system for controlling an idling speed for an outboard motor mounted on a boat and equipped with an internal combustion engine whose output is connected to a propeller through a clutch such that the boat is propelled forward or reverse when the clutch is changed to a neutral position to a forward position or a reverse position, comprising:a secondary air supplier that supplies secondary air through a passage that is connected to an air intake pipe downstream of a throttle valve and that is equipped with a secondary air control valve such that an amount of secondary air is supplied to the air intake pipe in response to an opening of the secondary air control valve; clutch position detecting means for detecting whether or not the clutch is at a neutral position; engine operating condition detecting means for detecting parameters indicative of operating conditions of the engine including at least an engine speed; desired value determining means for determining a desired idling speed based on whether or not the detected position of the clutch is at the neutral position and for determining a desired secondary air supply amount such that a difference between the determined desired idling speed and the detected engine speed decreases; and valve controlling means for controlling the opening of the valve to a value that effects the desired secondary air supply amount; wherein the desired value determining means includes: comparing means for calculating a change of the desired secondary air supply amount and for comparing the change with a predetermined value when it is determined based on the detected position of the clutch that the clutch is changed; change direction determining means for determining whether the change of the desired secondary air supply amount is in an increasing direction or in a decreasing direction; and correcting means for correcting the desired secondary air supply amount by a predetermined correction amount in the determined direction, when the change is greater than the predetermined value.