Patent ID: 6599158
Filing Date: 2003-07-29
Classification: B63H,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 from a neutral position to a forward position or a reverse position, having: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 amount of secondary air is supplied to the air intake pipe in response to an opening of the secondary air control valve; engine operating condition detecting means for detecting parameters indicative of operating conditions of the engine including at least an engine speed; engine start-state determining means for determining engine start-state as to whether the engine has been started based on one of the detected parameters; desired value determining means for determining a desired idling speed and for determining a desired secondary air supply amount such that a deviation 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 improvement comprises: clutch position detecting means for detecting whether or not the clutch is at a neutral position, said clutch position detecting means being configured as a neutral switch to output either of two signals, one of said signals indicating that the clutch is in a neutral position and the other of said signals indicating that the clutch is in a forward or a reverse position such that the clutch position detecting means outputs the same signal when the clutch is in a forward position and when the clutch is in a reverse position; wherein the desired value determining means determines the desired idling speed and the desired secondary air supply amount based on the determined engine start-state and the detected clutch position.