Abstract: A spark ignition type internal combustion engine of the present invention is provided with a variable closing timing mechanism which can change a closing timing of an intake valve after suction bottom dead center wherein the amount of intake air fed into a combustion chamber is controlled mainly by changing the closing timing of the intake valve. At the time of engine cold start, the closing timing of the intake valve is advanced compared with the time of engine warm operation. At the time of engine cold start, the air-fuel mixture which is taken into a combustion chamber is blown back into the engine intake passage whereby the air-fuel ratio varies among cylinders, but according to the spark ignition type internal combustion engine of the present invention, it is possible to suppress such variation in the air-fuel ratio among cylinders.

Abstract: A choke system for an internal combustion engine includes a carburetor having a choke valve disposed in a passage; a cooling fan providing a variable air flow; an air vane moveable in response to the variable air flow; an air vane linkage coupling the air vane to the choke valve, the air vane linkage operating the choke valve by the movement of the air vane; a manually operated choke control; an override linkage coupling the choke control to the choke valve; and a thermally responsive member configured to engage the override linkage to retain the choke in a partially open position above a threshold temperature. The choke control may be moved to a first position in which the choke control overrides the thermally responsive member and the air vane linkage to maintain the choke valve in a closed position.

Abstract: An apparatus and method for improving vehicle performance by application of pneumatic boost to vehicle engines, including diesel engines having at least one turbocharger supplying air to the engine, in a manner which increases engine torque output while minimizing the potential for exceed various operating limits to the maximum practicable extent. The vehicle's pneumatic booster system controller implements strategies for shaping the rate of the air injection during a boost event, tailoring the air injection to obtain maximum engine torque output while respecting the operating limits, by controlling the timing, duration, quantity and/or injection pattern during a boost event to achieve a refined distribution of compressed air injection over the course of the boost event to provide desired engine torque output and fuel efficiency while minimizing the potential for exceeding a wide variety of operation limits, regulatory, engineering and passenger comfort limits.

Abstract: A control system for an engine includes a position determination module and a position control module. The position determination module determines a first cam phaser position for starting the engine prior to engine shut down, and determines a second cam phaser position for starting the engine while the engine is shut down. The position control module adjusts a cam phaser to the first cam phaser position at engine shut down. The position control module adjusts the cam phaser from the first cam phaser position to the second cam phaser at engine start up when a difference between the first cam phaser position and the second cam phaser position is greater than a predetermined difference. A method for controlling an engine is also provided.

Abstract: An internal combustion engine includes a muffler configured to reduce exhaust gas noise, a choke valve configured to control a flow of air in a carburetor, a thermally responsive element coupled with the choke valve and configured to move the choke valve in response to a temperature change in the thermally responsive element, and a thermally conductive member. The muffler has a housing defining an interior and an exterior. The thermally conductive member has a first portion positioned in the interior of the muffler in direct contact with the exhaust gases and extends through the muffler housing to the exterior of the muffler. The thermally conductive member also has a second portion positioned exteriorly of the muffler and coupled to the thermally responsive element, the thermally conductive member configured to conduct heat from exhaust gases within the muffler to the thermally responsive element.

Abstract: A method of controlling a choke valve of an engine with a controller is disclosed. Also disclosed is an automatic choke performing the method, an engine having the automatic choke, and an apparatus having the engine. The controller includes an electronic circuit, such as a programmable device, and is coupled to a temperature sensor and a motor. The method includes determining a temperature value using the temperature sensor, determining a time period to hold the choke valve in a first position, keeping the choke valve at the first position for the time period, moving the choke valve from the first position toward a second position using the motor, determining a count to hold the choke valve, keeping the choke valve at the second position for the count, and moving the choke valve from the second position toward a fully open position.

Abstract: A hybrid powertrain includes an internal combustion engine, an electro-mechanical transmission and an electric machine. In an engine starting routine, flow control devices located proximate each combustion chamber in the engine initially restrict airflow into the cylinders to allow for a starter motor to rotate the engine at lower expansion and compression torque whereafter rotation of the engine is transitioned to the electric machine.

Abstract: An exhaust valve early-closure control brings about blowback of exhaust gas into an intake system. However, if the exhaust valve early-closure control is executed, for example, during a first idle operation immediately following the startup of the engine, or the like, the amount of blowback exhaust gas becomes excessively large. Therefore, when the post-startup increase amount has decreased to or below a lower-limit criterion value, the ECU prohibits the exhaust valve early-closure control, and changes the control to a usual valve timing control. As a result, during a period during which the combustion state has a stability margin and the amount of emission of HCs and the like is large, the exhaust emission quality can be bettered by the exhaust valve early-closure control. Besides, when the post-startup increase amount has decreased, the combustion state can be stabilized by prohibiting the exhaust valve early-closure control.

Abstract: A method for starting an engine of a motor vehicle, the engine having an intake manifold, an intake throttle controlling admission of air into the intake manifold, and a plurality of combustion chambers communicating with the intake manifold, the method comprising providing a reduced pressure of air in the intake manifold prior to delivering fuel or spark to the engine, the reduced pressure of air responsive to a temperature of the engine; delivering fuel to one or more of the plurality of combustion chambers in an amount based on the reduced pressure of air; and delivering spark to the one or more combustion chambers to start the engine.

Abstract: An engine including an automatic choke that includes a choke valve movable between a fully closed position and a fully open position, a temperature sensor coupled to the engine and operable to provide a temperature signal indicative of a temperature of the engine, and a motor connected to the choke valve and operable to move the choke valve in response to a motor control signal. A controller is electrically connected to the motor and to the temperature sensor. The controller includes an electronic circuit having a memory. A table includes engine specific choke position data stored in memory, wherein the controller determines a choke initial position based on the temperature of the engine and the choke position data, and wherein the motor moves the choke valve toward that position in response to an attempt to start the engine.

Abstract: An internal-combustion-engine automatic stop and restart system performs restarting control by making the pinion pushing unit push out the pinion gear so as to engage with the ring gear, when the restarting condition is satisfied in a time period from a time when the automatic stopping condition is satisfied to a time when the rotation of the internal combustion engine stops. A throttle valve control unit opens the throttle valve even when the restarting condition has not been satisfied and stops control of the throttle valve in a time period from when the rotation of the internal combustion engine stops to when the restarting condition is satisfied, when the rotation speed of the internal combustion engine becomes lower than a predetermined value in a time period from when the automatic stopping condition is satisfied to when the rotation of the internal combustion engine stops.

Abstract: A method of operating a vehicle including an engine is provided The engine may include at least one cylinder, a boosting device to boost intake air to the at least one cylinder, a fuel tank, a fuel vapor canister to store fuel vapors vented from the fuel tank, and an emission control device to treat exhaust gas from the engine. The boosting device includes a compressor at least partially driven by an electric motor. The method includes during an engine cold start condition, operating the electric motor of the boost device to boost intake air, directing the boosted intake air through the fuel vapor canister to release a fuel vapor stored in the fuel vapor canister, directing the fuel vapor from the fuel vapor canister to the engine, and performing combustion in the at least one cylinder using the fuel vapor during the engine starting.

Abstract: In at least some embodiments, the present invention relates to an automatic choke system for use in an engine having a muffler and a choking mechanism that are located remotely apart from one another. The system includes a thermally responsive device, at least one component that serves to connect, at least in part, the device to the choking mechanism, and a further mechanism for conveying heat from the muffler to the device. Additionally, the system in at least one embodiment includes at least one of: (a) a pipe for conveying a fluid from a first location proximate the muffler to a second location proximate the device, the pipe being comprised within the further mechanism; and (b) a rotatable axle that spans a majority of a distance between the first location and a third location that is proximate the choking mechanism, the axle being comprised within the at least one component.

Abstract: A method of evaluating intake air temperature (IAT) sensor rationality may include measuring a first intake air temperature associated with an engine using an IAT sensor when the engine is in a non-operating condition, determining a second intake air temperature associated with the engine using a hot wire air flow meter when the engine is in the non-operating condition, and indicating an IAT sensor fault when a difference between the first and second intake air temperatures exceeds a predetermined temperature limit.

Abstract: An engine provided with a variable timing mechanism (B) able to control a closing timing of an intake valve (7) and a variable compression ratio mechanism (A) able to change a mechanical compression ratio. At the time of engine startup, the closing timing of the intake valve (7) is made the most delayed position so that the least intake air is fed to the inside of the combustion chamber (5) and the mechanical compression ratio is made the maximum compression ratio.

Abstract: An engine starting control apparatus is basically provided with a motor control section, a valve timing control section and a start control section. The motor control section is configured to operate an electric motor to crank an engine with an output of the electric motor being adjustable. The valve timing control section is configured to operate a variable valve operating mechanism when the engine is started to change at least a close timing of an intake valve of the engine from an initial timing to a start timing such that the start timing is set closer to an intake bottom dead center during a single engine start as compared to the initial timing. The start control section is configured to adjust the output of the electric motor as the close timing of the intake valve changes from the initial timing to the start timing during the single engine start.

Abstract: In an intake system comprising a first intake passage (1) having an upstream end communicating with an intake duct (3) and a downstream end communicating with an intake port of an engine cylinder, a first intake control valve (6) provided in the first intake passage, a second intake passage (2) having an upstream end communicating with the intake duct and a downstream end communicating with the intake port of the engine cylinder, a second intake control valve (7) provided in the second intake passage, an accelerator pedal(ACL) and a control unit (100) for controlling opening angles of the first and second intake control valves, the second intake control valve is opened when the first intake control valve has opened to an effective opening angle and an intake air flow rate is required to be further increased.

Abstract: Methods and systems for controlling an engine are provided. In some examples, the engine has at least a cylinder and a compression device coupled to an intake of the engine, and the method includes, during engine re-start operation of an engine idle-stop condition, commencing combustion in the cylinder from a non-combusting condition, the combustion in a two-stroke combustion cycle of the cylinder. However, in some examples, at least partially electrically powered boosting operation may also be used to extend the two-stroke operation during a start.

Abstract: An engine starting assist system configured to be used on an internal combustion engine. The engine starting assist system includes a battery, a choke valve disposed in an air intake of an air/fuel-mixing device, the choke valve having an open position and a closed position, a rotary solenoid powered by the battery, the rotary solenoid having an output shaft, and a bimetal coil. The output shaft of the rotary solenoid is coaxial with the bimetal coil.

Abstract: Methods and systems are provided for controlling an engine of a vehicle. In one example, a throttle is adjusted improve engine restarting during an automatic engine stop where an operator requests an engine restart. The methods and systems may improve vehicle drivability.

Abstract: An auto choke device for an engine includes a choke valve for varying the opening of an intake passage of the engine, and a starter motor for starting the engine. Upon activation of the starter motor, the choke valve starts valve opening motion from a fully closed position. The choke valve continues the valve opening motion at a certain valve opening speed until it achieves a start opening set based on the temperature of the engine.

Abstract: A method for starting a vehicle engine includes determining a throttle angle command output based on a throttle adjustment parameter. The throttle angle command output may be further adjusted based on a learned compensation adder and may be based on a number of vehicle engine starts. A throttle angle corresponding to the throttle angle command output is provided.

Abstract: A starting system for a combustion engine including a carburetor with a throttle valve moveable between idle and wide open positions, a throttle control to control movement of the throttle valve during normal operation of the engine, and a linkage between the throttle control and the throttle valve. The starting system includes a recoil pulley, a pull-cord to rotate the recoil pulley, an actuator moveable in response to rotation of the recoil pulley, and a throttle override device. The throttle override device has a first control member moveable from a first position to a second position in response to movement of the actuator, and a second control member moveable in response to movement of the first control member from a first to a second position. The second control member is operably associated with the linkage to prevent the throttle valve from being in its wide open position when the second control member is in its second position.

Abstract: In a motorcycle engine, an air-intake port is opened upwardly, a throttle body is arranged so as to be inclined toward the front, and an idle-adjusting apparatus having an idle-adjusting lever is arranged at a position above a cylinder head and close to a cylinder head cover. The idle-adjusting lever is arranged at a relatively high position where a driver's hand reaches easily, thereby improving operability thereof. A fuel injection apparatus integrally includes the throttle body, an injector, and the idle-adjusting lever. The idle-adjusting lever is ergonomically arranged at a position substantially surrounded by the cylinder head cover, the throttle body and the injector, such that the idle-adjusting lever is arranged in a compact space, by which a compact layout of the engine is achieved.

Abstract: A fuel injection control apparatus includes: an internal combustion engine; a fuel injection unit provided in the internal combustion engine; an intake state detection unit that detects an intake state value indicating an intake state of the internal combustion engine, and that outputs an intake state signal; and a control unit to which the intake state signal is input, that determines based on the intake state signal whether or not the internal combustion engine is on an intake stroke, and that controls the fuel injection unit so that an initial fuel injection is performed in order to start up the engine when the control unit determines that the engine is on an intake stroke.

Abstract: A technique is provided for improved response of internal combustion engines to increased load demands. The engine is equipped with an air storage tank that stores compressed air. The air may be stored at an elevated pressure (e.g., manifold air pressure) during normal full load operation of the engine. Valving maintains the compressed air isolated during normal operation. During transitory periods of higher power output demand, the compressed air is directed to the engine, and output of a turbo-driven compressor can be vented to avoid surge. The technique allows for quicker reaction to load demands, and improved combustion during transitory periods, and reduced particulate and smoke emissions.

Abstract: Startability of an internal combustion engine using a mixed fuel of gasoline and alcohol is improved. An intake passage of the engine has a main flow channel provided with a throttle valve and a bypass flow channel for bypassing the throttle valve. A bypass quantity adjusting mechanism adjusts the bypass quantity in the bypass flow channel. A control device detects or estimates the mixing ratio of alcohol of the fuel and controls the bypass quantity adjusting mechanism so that a bypass quantity before a first explosion is smaller than a bypass quantity after the first explosion when the mixing ratio of alcohol is equal to or more than a predetermined value.

Abstract: An internal combustion engine having a plurality of banks; each having a cylinder provided to said banks comprising: an intake valve provided between said cylinder and an intake manifold a camshaft opening and closing said intake valve by means of mechanical power of said internal combustion engine; and a changing unit changing, according to an operating state of said internal combustion engine a phase angle of said camshaft said phase angle corresponding to a closing timing of said intake valve said banks differing from each other in most retarded phase angle changed by said changing unit.

Abstract: Methods and systems for controlling an internal combustion engine are provided. The method may include opening and closing an intake valve respectively at first opening and closing timings of a cylinder cycle during an engine start when a temperature of the internal combustion engine is below a predetermined temperature, and opening and closing the intake valve respectively at second opening and closing timings of a cylinder cycle during an engine start when a temperature of the internal combustion engine is above the predetermined temperature. The second closing timing may be later than the first closing timing and after a bottom dead center of an intake stroke of the cylinder cycle. The second opening timing may be earlier than the first opening timing, and a difference between the first and second closing timings may be greater than a difference between the first and second opening timings.

Abstract: Procedure for starting a combustion engine with at least one combustion chamber, whereby injections from the high pressure system are deposited into the combustion chamber during the starting process, is thereby characterized, in that at least one injection into the combustion engine can be blanked out in order to limit a pressure drop in the high pressure system.

Abstract: The invention relates to an internal combustion engine operable in homogeneous charge compression ignition (HCCI) combustion mode and in conventional spark ignited combustion mode and a method for restart of HCCI combustion therein. Whilst cranking the exhaust valve is arranged to be closed before top dead center (TDC) during an exhaust stroke. The intake valve is arranged to be opened after TDC during an induction stroke. Fuel injection control means are arranged to perform a first fuel injection after closing of the exhaust valve and before TDC of the exhaust stroke. The ignition control means are arranged to cause said spark plug to ignite the first injected quantity of fuel before said opening of the intake valve. The fuel injection control means are arranged to perform at least one further fuel injection in the interval after TDC of the exhaust stroke and before TDC of a subsequent compression stroke.

Abstract: A method for starting a vehicle engine includes determining a throttle angle command output based on a throttle adjustment parameter. The throttle angle command output may be further adjusted based on a learned compensation adder and may be based on a number of vehicle engine starts. A throttle angle corresponding to the throttle angle command output is provided.

Abstract: In order to provide a carburettor unit for motorized equipment, in particular hand-operated motorized equipment such as a chain saw, a trimmer, a lawn-cutting appliance, a foliage clearing appliance or suchlike, having a housing, in which a throttle valve and a choke valve are held so as to be movable respectively between a closed position and an open position, which overcomes the disadvantages of the prior art and in which an incorrect position between the throttle valve and the choke valve is avoided, it is proposed that a locking element is provided, which is adjustable through the movement of the throttle valve and cooperates with the choke valve such that a movement of the choke valve into the closed position is locked when the motorized equipment is set in operation.

Abstract: A control device of an internal combustion engine includes: a target negative pressure setting section that set a target negative intake pipe pressure during cold acceleration to a negative intake pipe pressure larger than a negative intake pipe pressure prior to the cold acceleration; a throttle valve control section that controls a throttle valve so that the negative intake pipe pressure increases during cold acceleration; and an intake valve control section that controls a variable valve mechanism of an intake valve, based on the target negative intake pipe pressure, to obtain a target intake air amount.

Abstract: An intake control device of an internal combustion engine in which an intake path of each cylinder is partitioned into an upper and a lower path and a tumble control valve and an intake pressure control valve are provided to open/close the upper path and lower path respectively. In a given driving condition, the intake air flow velocity in the lower path is increased by closing the tumble control valve, thereby generating a tumble flow in the combustion chamber. In this process, the intake pressure control valve is opened around start of an intake stroke and closed around its end to make intake pressure downstream of the intake pressure control valve higher than upstream of it to increase the difference between upstream and downstream intake pressures in the intake stroke. This increases the intake air flow velocity in the lower path and intensifies the tumble flow in the combustion chamber.

Abstract: The invention aims to prevent the dust passing through a gap provided for sliding movement of bypass valve from being attached to a screw mechanism, and thus to guarantee smooth motion of the screw mechanism. Provided is a bypass-intake-flow control apparatus including a throttle body in which a bypass and a valve hole that is open into the course of the bypass are formed. A bypass valve to open and close the bypass is slidably but not rotatably fitted into the valve hole. An actuator is attached to the throttle body with an output shaft arranged coaxially with the bypass valve. The screw mechanism links the output shaft and the bypass valve. A bottomed hollow portion is formed in the bypass valve with an opening facing the actuator. A dust cover that surrounds the screw mechanism in the hollow portion is attached to the throttle body.

Abstract: A control device is configured for use with an engine of a power equipment apparatus. The control device includes a base, a first knob, and a second knob. The first knob is positioned adjacent to the base and is rotatable about an axis with respect to the base while being substantially restrained from axial movement along the axis with respect to the base. The first knob has an aperture surrounding and extending along the axis to define a passageway extending through the first knob. The second knob has an end portion slidingly received within the aperture of the first knob such that the second knob is axially movable along the axis with respect to the base and the first knob. Power equipment apparatus and saddle-type vehicles including control devices are also provided.

Abstract: An automatic choke connectable to an engine. Also disclosed is an engine including the automatic choke, an apparatus including the engine and the automatic choke, and a method of controlling a choke valve. The automatic choke includes a motor for moving a choke valve and a controller electrically connected to the motor. In one construction, the controller is configured to store position information and a flag related to a position of the choke valve, determine the engine has, and control the automatic choke with the stored position information based on the flag and the determination that the engine has re-started. In another construction, the controller is configured to generate a motor control signal to direct the choke valve to a fully-open position without providing choke relief based on a temperature value indicating the engine temperature is greater than a threshold.

Abstract: A method of controlling a choke valve of an engine with a controller is disclosed. Also disclosed is an automatic choke performing the method, an engine having the automatic choke, and an apparatus having the engine. The controller includes an electronic circuit, such as a programmable device, and is coupled to a temperature sensor and a motor. The method includes determining a temperature value using the temperature sensor, determining a time period to hold the choke valve in a first position, keeping the choke valve at the first position for the time period, moving the choke valve from the first position toward a second position using the motor, determining a count to hold the choke valve, keeping the choke valve at the second position for the count, and moving the choke valve from the second position toward a fully open position.

Abstract: In a general-purpose engine having a throttle valve installed in an air intake passage connected to a combustion chamber, sucked air mixing with fuel to generate an air-fuel mixture to be ignited to drive a piston to rotate a crankshaft connected to a load, a first warm-up time period during which the engine is warmed up and a second warm-up time period which is longer than the first time period are determined based on detected engine temperature and a fuel quantity is increased during the first time period. The operation of the motor is controlled such that a change rate of throttle valve opening is limited within a range until the measured time exceeds the second warm-up time period after it exceeded the first time period. With this, it becomes possible to complete warm-up operation in a short period of time, while improving rate of fuel consumption and emission performance.

Abstract: Provided is an intake manifold pressure control apparatus, or vacuum pump, for a hybrid propulsion system. The vacuum pump is operable to evacuate the intake manifold of an internal combustion engine, thereby lowering the Manifold Absolute Pressure, or MAP, to a predetermined level to enable a quick restart of the internal combustion engine. This vacuum pump may also be used to evacuate hydrocarbons, or HCs, from within the intake system to prevent evaporative emissions from the intake manifold upon engine shutdown. In the preferred embodiment, the vacuum pump is operated by a motor that can simultaneously operate an auxiliary transmission oil pump. Additionally, the present invention provides a method of controlling the hybrid propulsion system to enable the manifold pressure control apparatus to lower the MAP value within the intake manifold as well as a method of evacuating HCs from the intake manifold upon engine shutdown.

Abstract: A carburetor (1, 51) has an intake channel (2) wherein a throttle element and a choke element are arranged with the choke element being upstream of the throttle element. The choke element is displaceable between an operating position (8) and at least one starting position (9). A first fuel path is provided which supplies fuel to the intake channel section (2) in dependence upon the underpressure present therein. A first controllable valve (20) for controlling the supplied fuel quantity is mounted in the first fuel path. In order to achieve an adapted fuel supply in different operating states, a second fuel path is provided which defines a bypass line to the first valve (20). A second valve (44, 54) is mounted in the second fuel path. A method for operating the carburetor (1, 51) provides that the second valve (44, 54) is actuated in dependence upon at least one operating parameter of the carburetor (1, 51).

Abstract: A technique is provided for improved response of internal combustion engines to increased load demands. The engine is equipped with an air storage tank that stores compressed air. The air may be stored at an elevated pressure (e.g., manifold air pressure) during normal full load operation of the engine. Valving maintains the compressed air isolated during normal operation. During transitory periods of higher power output demand, the compressed air is directed to the engine, and output of a turbo-driven compressor can be vented to avoid surge. The technique allows for quicker reaction to load demands, and improved combustion during transitory periods, and reduced particulate and smoke emissions.

Abstract: The present invention has an object of providing a technology capable of stopping and starting an internal combustion engine more preferably by restraining vibrations when the internal combustion engine stops and a scatter in crank angle when the internal combustion engine stops. For a period till an actual stop of the internal combustion engine since a stopping condition of the internal combustion engine was established, an air quantity of air flowing into a cylinder of the internal combustion engine is decreased when a number of revolutions of the engine is higher than a specified number of revolutions (S102) and is increased when the number of revolutions of the engine is equal to or lower than the specified number of revolutions (S106).

Abstract: In at least a first cycle at startup, an opening timing of an exhaust valve is controlled to 45 degrees before-bottom-dead-center of an exhaust stroke, or to a retard side of the normal closing timing that is set after warm-up is complete. Also, the closing timing of the exhaust valve is preferably controlled to an advance side of top-dead-center in a second cycle at startup and thereafter at the latest. Accordingly, the amount of unburned HC discharged during a cold start of an internal combustion engine is reduced.

Abstract: A method for improving engine starting for an engine having a variable event valvetrain is described. According to one aspect of the description, valve timing during a start can be set so that combustion stability and emissions may be improved.

Abstract: An engine starting assist system configured to be used on an internal combustion engine. The engine starting assist system includes a battery, a choke valve disposed in an air intake of an air/fuel-mixing device, the choke valve having an open position and a closed position, a rotary solenoid powered by the battery, the rotary solenoid having an output shaft, and a bimetal coil. The output shaft of the rotary solenoid is coaxial with the bimetal coil.

Abstract: A control device is configured for use with an engine of a power equipment apparatus. The control device includes a base, a first knob, and a second knob. The first knob is positioned adjacent to the base and is rotatable about an axis with respect to the base while being substantially restrained from axial movement along the axis with respect to the base. The first knob has an aperture surrounding and extending along the axis to define a passageway extending through the first knob. The second knob has an end portion slidingly received within the aperture of the first knob such that the second knob is axially movable along the axis with respect to the base and the first knob. Power equipment apparatus and saddle-type vehicles including control devices are also provided.

Abstract: The present invention relates to a carburetor of an internal combustion engine having a manually activated start position. The carburetor comprises at least a choke valve and a throttle valve both located in the carburetor's main air passage which are able to move between an open and a closed position, each valve having at least one respective lever that cooperates during the manual activation to give at least one start position of the choke and throttle valves. The carburetor further usually comprises at least one thermally responsive member arranged to affect the start position. Further a handle is arranged to provide a two stage draw—lift motion to attain the start position.

Abstract: The present invention provides an intake air control that is capable of suppressing the exhaust emission at engine startup and quickly activating a catalyst after engine startup. An engine has a variable valve actuation mechanism for continuously adjusting at least a lift amount of an intake valve to control an intake air amount. At startup of the engine, the lift amount is set in accordance with the number of times that a piston in a cylinder of the engine has passed through a top dead center until a rotational speed of the engine reaches an idle rotational speed. After an engine water temperature becomes greater than a predetermined value, the lift amount is corrected using a proportion term that is determined based on the engine rotational speed and an integral term that is determined based on a difference between the engine rotational speed and the idle rotational speed until the engine rotational speed reaches the idle rotational speed.