Abstract: A fuel system for a vehicle has a fuel tank, a fuel line in communication with the fuel tank, a carburetor having an inlet side and an outlet side, a return line connected to the outlet side of the carburetor and communicating with the fuel tank, and a nozzle positioned in the return line. The fuel line is connected to the inlet side of said carburetor so as to pass fuel into a fuel bowl of the carburetor. The nozzle has an orifice formed therethrough. The orifice of the nozzle has a diameter of between 0.005 and 0.050 inches. The nozzle is in sealed relationship with an inner wall of the return line.

Abstract: A throttle assembly for intake air protects a link mechanism for interlocking throttles with each other from water and mud and maintains the throttle operability in a satisfactory state. The throttle assembly for intake air includes a plurality of throttle devices for injecting fuel into intake air to generate an air-fuel mixture; a link mechanism for connecting driving portions of the throttle devices with each other, a link mechanism housing chamber defined by an outer wall member for forming a link mechanism housing chamber and housing the link mechanism, and seal members provided at the connected or mated portions of the outer wall member and a different member or the connected or mated portions of a plurality of outer wall configuring members which configure the outer wall member.

Abstract: A V-type engine includes: first and second banks which are arranged in a V-shape and which respectively have cylinder bores; a crankshaft which is shared by the first and second banks; a crankcase which supports the crankshaft, the first and second banks being connected to the crankcase; and a valley portion which is defined between the first and second banks, an engine auxiliary machine being disposed in the valley portion. The first and second banks are arranged so that a cylinder center line of the first bank and a cylinder center line of the second bank respectively pass through a point which is eccentric from a rotational center of the crankshaft to a side opposite from both the banks. Thus, it is possible to improve an auxiliary machine housing function of the valley portion defined between the first and second banks while maintaining a predetermined opening angle therebetween.

Abstract: An air supply unit for an internal combustion engine; the air supply unit is provided a number of butterfly valves and a distributor device, the latter being provided, for each butterfly valve, with a distribution duct capable of placing an internal duct of said butterfly valve in communication with a chamber of the distributor device connected to an intake box by means of a first air duct regulated by a solenoid valve; inside the distributor device, each distribution duct is connected to the intake box by means of a corresponding second air duct regulated by a respective bypass screw and is connected to a corresponding regulation duct opening into an air intake, which is accessible from the outside of the distributor device and is normally closed by an associated removable plug.

Abstract: To improve productivity of a connection member between first and second carburetors, and to reduce maintenance work area for a main drive throttle valve lever, a driven throttle valve lever and a connection lever, a main drive throttle valve lever is arranged to protrude in one side of a first carburetor, a driven throttle valve lever is arranged to protrude in one side of a second carburetor, the main drive throttle valve lever and the driven throttle valve lever are connected in one side by a connection lever. A cup member provided with a bottom portion and a peripheral wall portion and formed in a cup shape is arranged fixedly in one side of the first and second carburetors, the first and second carburetors are connected by the cup member, an opening portion of the cup member is closed by a cover member, and the main drive throttle valve lever, the driven throttle valve lever and the connection lever are arranged so as to be received inside the cup member closed by the cover member.

Abstract: In an engine intake A/F ratio control system in an outboard engine system, a secondary air passage (P) for supplying secondary air for regulating the A/F ratio of an air-fuel mixture is connected to a carburetor (33) in an intake system of an engine (E), and a duty control valve (68) is connected to the secondary air passage (P). A duty control unit (92) is connected to the duty control valve (68) for controlling the duty ratio of a pulse applied to a coil (76) of the duty control valve (68), and an LAF sensor (94) is mounted to an exhaust system for detecting an A/F ratio of an exhaust gas to input a detection signal proportional to the A/F ratio of the exhaust gas to the duty control unit (92).

Abstract: An auto-enrichener for an engine, including an enriching conduit for carrying fuel and air to an engine, and a valve disposed in the conduit. The valve is adjustable between at least an open configuration and a closed configuration. In the open configuration passage of fuel and air through the conduit is enabled, and in the closed configuration passage of fuel and air through the conduit is not enabled. The auto-enrichener also includes a thermal expansion element in communication with the valve. The thermal expansion element expands with increasing temperature and contracts with decreasing temperature to activate the valve. The auto-enrichener also includes a heater that hears the thermal expansion element when the engine is operated.

Abstract: This invention provides a low cost, easily installed means of supplying supplemental fuel to an engine for the purpose of cold starting and enrichment, which also functions as a means for manual operator adjustment of low speed fuel flow. This system is easily adjusted by the operator while driving, requiring only one adjustment for a multi-cylinder engine. This system reduces the fuel delivery imbalance caused by the phase relationships of the fuel pressure pulses and the pressure pulses existing at the outlets of its fuel delivery orifices by using orifices of different areas.

Abstract: In an engine intake A/F ratio control system in an outboard engine system, a secondary air passage (P) for supplying secondary air for regulating the A/F ratio of an air-fuel mixture is connected to a carburetor (33) in an intake system of an engine (E), and a duty control valve (68) is connected to the secondary air passage (P). A duty control unit (92) is connected to the duty control valve (68) for controlling the duty ratio of a pulse applied to a coil (76) of the duty control valve (68), and an LAF sensor (94) is mounted to an exhaust system for detecting an A/F ratio of an exhaust gas to input a detection signal proportional to the A/F ratio of the exhaust gas to the duty control unit (92).

Abstract: A V-type two cylinder engine comprises: cylinders arranged forward and rearward such that they are inclined in V shape; a downdraft carburetor unit placed between the cylinders and including twin venturi bores provided for the respective cylinders and an air vent system making interior of carburetors communicate with atmosphere; intake manifolds each connecting a venturi bore of each of the carburetors to an intake port of a corresponding cylinder; and an air cleaner placed above the carburetors such that it covers the carburetors, and the carburetor unit is placed obliquely seen in a plan view according to positional difference between the cylinders in a direction of a crank shaft of the engine such that the venturi bore of each of the carburetors is closer to the intake port formed in a corresponding cylinder.

Abstract: The invention is directed to a method and an arrangement for synchronizing at least two power-adjusting elements of an internal combustion engine which are electrically driven independently of each other. For carrying out the synchronization, the intervals between the respective combustions or the corresponding segment times of at least two cylinders are detected to which individual power-adjusting elements are allocated and their deviation is determined. At least one power-adjusting element is adjusted in order to maintain this deviation within a pregiven tolerance band. A correction of the control of the power-adjusting elements is derived in dependence upon the adjustment. The power-adjusting elements are adjusted in mutually opposite directions.

Abstract: An intake air amount control system for an engine includes a plurality of throttle devices each of which is comprised of a butterfly-type throttle valve rotatably carried in an intake passage body and which are disposed in a pair at two points spaced from each other in a direction perpendicular to rotational axes of the throttle valves. The intake passage bodies of the throttle devices disposed at the two points are connected to each other by at least one connecting member. In such intake air amount control system, bypass air passages are provided on opposed sides of the intake passage bodies forming a pair to extend around the throttle valves, respectively, and air control valves mounted on the opposed sides of the intake passage bodies for controlling the opening degrees of the bypass air passages, respectively. A synchronizing mechanism is disposed between the pair of throttle devices for synchronizing the operations of the air control valves.

Abstract: To simplify the idle opening amount between each cylinder and simplify the structure of a throttle body, starter valves having tuning screws capable of respectively adjusting the flow amount of air supplied to the intake port of each throttle body are arranged in a line in a valve body. Due to the provision of the valve body, a joint pipe for supplying air having a flow amount is adjusted using the starter valves. The throttle bodies are connected through a bypass tube to the valve bodies such that the valve bodies are separated from the throttle bodies.

Abstract: An intake control mechanism for controlling the flow of air through an air intake of an engine is disclosed. The air intake comprises an intake member defining an intake passage corresponding to each combustion chamber of the engine. A throttle valve and a choke valve are movable positioned in each passage. The intake control mechanism includes a choke control and throttle control for moving the choke and throttle valves, respectfully. The choke control includes a choke linkage and the throttle control includes a throttle linkage, the linkages positioned outside of the intake member and between the choke and throttle valves. Preferably, the choke linkage is positioned between the throttle linkage and the intake member.

Abstract: A fuel supplying system for a vertical engine provided with multiple cylinders arranged in a vertical direction, respectively, in an installed state of the engine and a crankshaft disposed vertically therein, comprising a plurality of fuel supplying means disposed for the cylinders, respectively, said fuel supplying means being divided into plurality of groups. A plurality of fuel pumps each disposed for each of said groups of the fuel supplying means, said fuel pumps being arranged below the fuel supplying means at a lowest position of the corresponding each group of the fuel supplying means. Further, a plurality of fuel diverging means operatively connecting the fuel pumps to the each group of the fuel supplying means, respectively, said fuel diverging means being connected to each other through connecting means.

Abstract: A multi-cylinder engine structure includes a multi-cylinder engine body having a plurality of cylinders vertically arranged therein. A fuel feed system has a fuel pump connected to a plurality of carburetors disposed in a vertical arrangement sideways of the engine body in independent correspondence to the cylinders. The fuel pump is disposed below a lowermost one of the plurality of carburetors arranged vertically. An outboard engine includes a case tiltably mounted at a stern. A multi-cylinder engine body is contained in the case. A fuel feed system supplies a fuel to a plurality of carburetors disposed in correspondence with the cylinders. A fuel filter is also provided. The fuel pump is disposed below a lowermost one of the plurality of carburetors arranged vertically and above the fuel filter in a tilted-down state of the case.

Abstract: A mounting arrangement for an accelerator pump and a choke actuation mechanism, which are used in conjunction with a plurality of charge formers, minimizes the girth of the engine while making these components more accessible and easing assembly. An actuator and a choke solenoid of the choke actuation system are mounted proximate to one another and partially between adjacent induction pipes of an induction system. This position allows these components to be located on an exterior side of the induction system without interfering with the protective cowling of the motor. The accelerator pump is mounted at the end of a series of charge formers, proximate to a throttle linkage which controls throttling devices of the charge formers. This position of the accelerator pump eases the installation of this component without increasing the girth of the engine.

Abstract: A fuel delivery system for an engine having multiple, vertically spaced charge formers, and the system is provided with a fuel conduit arrangement so that the individual conduits serving the individual charge formers are kept relatively short in length, but the conduits are interconnected in such a way that any vapor which may form in the conduits will flow vertically upwardly for purging from the system.

Abstract: A fuel injection and control system for a V-type, two cycle, crankcase compression, internal combustion engine. The fuel injection system includes fuel injectors positioned in the valley of the engine and which are supplied with fuel under pressure from a fuel tank through a line in which a fuel filter and fuel pump are positioned. The fuel pump and fuel filter are disposed at one end of the engine and the amount of pressure supplied to the fuel injectors is controlled by a pressure regulator that regulates pressure by bypassing excess fuel back to the fuel filter upstream of the filter element. A throttle control and throttle position sensor are disposed at the opposite end of the engine and exhaust control valves are provided outside of the valley of the "V" of the engine.

Abstract: A multi-cylinder engine structure includes a multi-cylinder engine body having a plurality of cylinders vertically arranged therein. A fuel feed system has a fuel pump connected to a plurality of carburetors disposed in a vertical arrangement sideways of the engine body in independent correspondence to the cylinders. The fuel pump is disposed below a lowermost one of the plurality of carburetors arranged vertically. An outboard engine including a case tiltably mounted at a stern. A multi-cylinder engine body is contained in the case. A fuel feed system supplies a fuel to a plurality of carburetors disposed in correspondence to the cylinders. A fuel filter is also provided. The fuel pump is disposed below a lowermost one of the plurality of carburetors arranged vertically and above the fuel filter in a tilted-down state of the case.

Abstract: The invention is directed towards a fuel enrichment system for a multi cylinder internal combustion engine. Each cylinder of the engine is served by a separate carburetor. Manifold passageways are interposed between the cylinders and the respective carburetors for supplying the fuel/air mixture to the cylinders. The system further includes a balance passage which provides communication between each of the passageways. A starting fuel/air mixture is delivered to the cylinders through the balance passage.

Abstract: A fuel increasing system for an internal combustion engine having a normal charge forming system with a plurality of carburetors. A supplemental fuel supplying system is incorporated that draws fuel from the fuel bowl of one of the carburetors to a supplemental fuel pump which, in turn, delivers fuel under pressure to a pressure regulating valve which regulates pressure by discharging excess fuel back to the fuel bowl from which it is drawn. The discharge of supplemental fuel to the engine is controlled by individual supplemental fuel control valves mounted on each of the carburetors.

Abstract: A low cost multi cylinder radial aircraft engine is composed of an even number of individually functional, single cylinder slider crank model engines. They are mounted to a plate to form equally spaced radially oriented cylinders. In the preferred embodiment, use of standard, low cost, & mass produced two cycles engines are used. This in conjunction with a novel exhaust muffler and throttle mechanism results in a low cost radial engine. The individual engine shafts surround and are parallel to a central output shaft. Pinion gears on each shaft transfer power to a larger sun gear on the output shaft. This gearing synchronizes opposed pistons to reach top dead center at the same time resulting in vibration free piston motion and perfect balance of the entire engine. Said gearing also provides speed reduction for use of large diameter scale propellers. A rear mounted throttle mechanism controls individual carburetor throttles.

Abstract: A manifold is provided for a multicylinder engine, particularly a motorcycle engine, wherein separate, independent passages are provided to connect separate carburetors to individual cylinder inlet ports. A plurality of such passages are provided in a single manifold casting, preferably each passage having a constant cross-sectional area throughout its length and all passages being identical in cross-sectional area and length. The actual cross-sectional shape of each passage may vary along its length due to space restriction for said manifold.

Abstract: A fuel enrichment system for a multi-cylinder engine having a manifold balance line to deliver fuel to each of the cylinders as needed includes a valve located adjacent one of the carburetors to supply additional air/fuel mixture to approximately the center of the fuel balance line during the start-up of the engine.

Abstract: An internal-combustion engine which includes two cylinder groups, of which one cylinder group operates constantly, whereas the second cylinder group is inactive in a part-load operation for better fuel economy. However, during forward or reverse operation of the vehicle and during the warm-up phase of the internal-combustion engine, the second cylinder group is provided with a reduced fuel-air mixture to prevent the engine from dying. An actuating device is provided which responds to certain parameters such as engine temperature and gear position. This actuating device controls a radial cam which interacts with the throttle valve for the second set of cylinders during these conditions to supply the required fuel-air mixture.

Abstract: An induction system for an internal combustion engine wherein each chamber of the engine is provided with three intake ports and one charge former serves two of those intake ports while another charge former serves the other intake port. The charge formers employ a staged throttle valve arrangement so that the other charge former supplies the idle and low speed requirements and the first mentioned charge former comes into operation only at high speeds and loads. In accordance with another feature, the arrangement is provided for pairs of chambers and the single charge former serves two chambers.

Abstract: An air-fuel ratio control device for an internal combustion engine equipped with a plurality of variable venturi type carburetors each having a slow system, in which the flow rate of air supplied to the slow systems of the carburetors is controlled depending on the engine operation parameters including, for example, the temperature of intake air, temperature of engine oil and atmospheric pressure to improve the rate of atomization of fuel, thereby improving the idling performance of the engine and therefore improving the fuel consumption of the engine.

Abstract: Intake device for multiple cylinder I.C. engine, the intake opening of the carburetor for each cylinder being connected with a carburetor base connected to an air cleaner in chamber form. The chamber intake openings for each carburetor are separated by partition plates.

Abstract: An idling controller for a variable displacement engine which is capable of operating either in a partial-cylinder or an all-cylinder mode by varying the number of cylinders in operation. When the engine runs at idle, the idling controller assures optimum operation for either cylinder operating mode by varying the quantity of air intake according to the number of cylinders in operation, providing an improvement in both fuel mileage and strating performance, one or the other of which has had to be sacrified conventionally.

Abstract: A multiple cylinder engine of the type which is capable of controlling the number of operating cylinders to operate the engine in either in full or partial displacement mode, wherein the operation is switched smoothly between the full displacement and partial displacement in a simplified manner by detection of the pressure in the intake passage of the engine, putting the engine into full displacement mode by a control pressure when the engine is in cold state preferentially to the pressure in the intake passage, thereby shortening the time period of warming up to achieve smooth operation of the engine quickly.

Abstract: In a multi-cylinder internal combustion engine having a plurality of cylinders which are supplied with air via one common throttle valve and a control unit for regulating the number of operating cylinders which suspends the operation of an arbitrary number of cylinders by intercepting the air supply to said cylinders, it is noted at a point the output of the engine under Z.sub.1 -cylinder operation coincides with the output under Z.sub.2 -cylinder operation at the same degree of opening of the throttle valve at a given constant rate of engine rotation. Based on such a fact, the multi-cylinder internal combustion engine is made capable of shifting to and from Z.sub.1 -cylinder operation and Z.sub.2 -cylinder operation in the proximity of said point where these outputs coincide. This way, there will be no fluctuation in the output nor shock at the time of switching, and the control unit for this purpose can be made simple in construction.

Abstract: A carburetor device for V-type internal combustion engines having first and second cylinders disposed in a form like V and first and second carburetors disposed between those cylinders and adapted to supply a gaseous mixture to the associated cylinders independently. The first and second carburetors are provided with first and second intake barrels, respectively, which adjacently intersect each other and have intake passages defined therein for communication with the corresponding first and second cylinders. The carburetors further include first and second float chambers located below a point of intersection of the intake barrels with their side surfaces partially opposed to each other. In the opposed surfaces of the float chambers are opened inlets of the fuel admission ports to which inlets are fitted the opening ends of two linearly-arranged distribution pipes of a T-type joint.

Abstract: A multicylinder engine whose working cylinders are variably controlled in number to suit operating requirements, with an air fuel mixture fed from a single throttle valve to the working cylinder or cylinders through an intake manifold, includes at least one normally closed control valve installed in at least one intake pipe of the intake manifold. When the throttle valve has opened to a prescribed degree, the control valve instantly opens fully or almost fully or to a prescribed degree, independently of the throttle valve.

Abstract: In a multi-cylinder internal combustion engine having a plurality of cylinders which are supplied with air via one common throttle valve and a control unit for regulating the number of operating cylinders to rest an arbitrary number of cylinders by blocking the air supply to said cylinders, the output of the engine under Z.sub.1 -cylinder operation is known to come to coincide with the output under Z.sub.2 -cylinder operation at one point with the same degree of opening of the throttle valve under a given constant rate of the engine rotation. At such a point, the pressure of the intake manifold under both the Z.sub.1 -cylinder operation and the Z.sub.2 -cylinder operation remain at or close to a certain value respectively over a wider range of rotation of the engine. This multi-cylinder internal combustion engine enables smooth switching between the Z.sub.1 -cylinder operation and the Z.sub.

Abstract: An improved carburetion system for a V-type internal combustion engine including a first carburetor and a second carburetor disposed in a space between a first cylinder and a second cylinder arranged in the form of V-shape and adapted to supply an air-fuel mixture to the respective cylinders, said carburetors each having an intake barrel defining an intake passage leading to the associated cylinder respectively. A common intake box having at least an air inlet opening formed on the side walls thereof is provided between both the first and second cylinders in such a manner that the first and second carburetors are connected to said common intake box. Each of the intake barrels has an inlet port which is opened toward the interior of the common intake box and an air horn made of resilient material is connected to said inlet port so that said air horn extends into the interior of the common intake box.

Abstract: A multicylinder engine whose working cylinders are variably controlled in number to suit operating requirements, with an air fuel mixture fed from a single throttle valve to the working cylinder or cylinders through an intake manifold, includes at least one normally closed control valve installed in at least one intake pipe of the intake manifold. When the throttle valve has opened to a prescribed degree, the control valve instantly opens fully or almost fully or to a prescribed degree, independently of the throttle valve.

Abstract: A multicylinder engine whose working cylinders are variably controlled in number to suit operating requirements, with an air fuel mixture fed from a single throttle valve to the working cylinder or cylinders through an intake manifold, includes at least one normally closed control valve installed in at least one intake pipe of the intake manifold. When the throttle valve has opened to a prescribed degree, the control valve instantly opens fully or almost fully or to a prescribed degree, independently of the throttle valve.

Abstract: A carburetion system for V-type internal combustion engine having a first carburetor and a second carburetor disposed in a space between a first cylinder and a second cylinder arranged in a form like V and adapted to supply air-fuel mixture to respective cylinders independently, improved to have a compact structure and superior intake charging efficiency with capability of substantially uniformly supplying the mixture during acceleration and deceleration of the vehicle. The carburetors have intake barrels defining therein intake passages communicating with the associated cylinders. The intake barrels are disposed substantially at right angles to the axes of the associated cylinders and in the close proximity of each other in such a manner as to partially cross each other. A pair of float chambers are disposed between the intake barrels below the point of crossing of the intake barrels.

Abstract: An improved carburetion system for a V-type internal combustion engine including a first carburetor and a second carburetor disposed in a space between a first cylinder and a second cylinder arranged in the form of V-shape and adapted to supply an air-fuel mixture to the respective cylinders. The respective carburetors each includes an intake barrel and a float chamber in which fuel to be supplied to said intake barrel is stored, said intake barrel having an inlet port and an outlet port and defining an intake passage leading to the associated cylinder. The intake barrels of both the carburetors are arranged in the ultimate proximity of one another in such a manner that they intersect one another and a point of intersection of the intake barrels is offset from the middle part of the intake barrels toward the inlet port of the latter. Thus, the respective float chambers are located in a space between both the intake barrels below the point of intersection.

Abstract: An internal combustion engine is disclosed which comprises first and second cylinder units each including at least one cylinder, an induction passage divided downstream of the throttle valve into first and second intake passages leading to first and second cylinder units, respectively, a vacuum tank held at a vacuum above that in the induction passage downstream of the throttle valve, a stop valve provided at the entrance of the second intake passage and adapted to move toward its closed position when connected to the vacuum tank, and a control circuit adapted to block the supply of fuel to the second cylinder unit and connect the vacuum tank to the stop valve thereby shifting the engine operation into a split engine mode when the engine load is below a predetermined value.

Abstract: An internal combustion engine is disclosed which includes first and second cylinder units, an intake manifold divided into first and second intake passages leading to the first and second cylinder units, respectively, an exhaust manifold divided into first and second exhaust passages leading from the first and second cylinder units, respectively, and control means for providing a control signal to disable the second cylinder unit when the engine load is below a predetermined value. The second intake passage has therein a first normally open valve adapted to close in response to the control signal. The second exhaust passage has therein a second normally open valve adapted to close in response to the control signal. Pressure control means is provided which is responsive to the control signal for supplying a predetermined pressure not less than atmospheric pressure to the second intake passage, thereby maintaining the second intake passage at the predetermined pressure.

Abstract: An exhaust gas purifying system for an automobile engine including at least first and second engine cylinder has a shutter valve for interrupting the supply of a combustible air-fuel mixture to the first engine cylinder during a particular engine operating condition, a three-way electromagnetically operated valve for controlling the operation of the shutter valve, and a secondary air supply unit including a switching valve for selectively supplying a secondary air to a portion of an exhaust passage upstream of at least one catalyst unit disposed in the exhaust passage.

Abstract: A cold start fuel enrichment system for an internal combustion engine uses fuel from the upper carburetor for enriching the air-fuel mixture in the lower carburetors by gravity feed. A fuel line runs from the upper carburetor float bowl to the throttle bores of the lower carburetor. A solenoid valve in the fuel line controls its operation.