Abstract: A method for manufacturing a disk for a belt-driven continuously-variable-speed drive of the type which includes a metal belt disposed in engagement between mutually facing sheave surfaces which form a V-groove, including the steps of machining each sheave surface with a numerical control lathe to form therein a spiral groove that is centered about the center of the pulley and has a surface roughness within the range of 0.8-0.4 microns, and thereafter super finishing the sheave surfaces to produce residual stress therein.

Abstract: A piston member for an internal combustion engine of, for example, a motor bicycle is provided with bosses having inner end surfaces opposing to each other into which a piston pin is inserted. A connecting rod has small and large end portions and the small end portion is slidably coupled with the end surfaces when the connecting rod is inserted into the body of the piston member through a cutout portion formed at one end thereof to form a skirt portion. The sizes, dimensions, and structures of the end surfaces of the bosses, the cutout portion, and the associated elements are determined to be suitable for coating thin films of metallic particles on the end surfaces by flame coating means.

Abstract: A steering mechanism of an aquatic vehicle having a hull comprises a stationary housing secured to the hull on a deck side thereof, a movable housing to be engaged with the stationary housing, and a steering pole having a base end secured to the movable housing and a free end to which a handle member is secured. Either one of the stationary housing and the movable housing is provided with arcuate guide grooves each having an imaginary center of curvature about which the steering pole is rotated and which is positioned in the inner side of the hull and a movable mechanism to be engaged with the arcuate grooves is disposed on the other one of the stationary housing and the movable housing.

Abstract: A vocal alarm arrangement includes a plurality of sensors, including a sensor for detecting an abnormality in cooling water, a sensor for detecting an abnormality in an oil level, and the like, and also includes a voice outputting circuit to which outputs from the sensors are coupled and which displays abnormalities in a vocalized form, the outputs from the plurality of sensors being given a predetermined order of priority, and the signals from the sensors being processed in accordance with the specified order of priority so abnormalities are presented as alarms in a vocalized form according to such order priority.

Abstract: An air cleaner is provided in the air intake system for an internal combustion engine. An air intake port is provided at the inlet to the air cleaner. A suction air passage is provided in the air intake port and has a cross section that gradually decreases along the air flow direction.

Abstract: A rotational speed control system for an engine includes controls for determining whether the throttle is closed beyond a predetermined position, whether the engine is mechanically loaded, and whether the engine rotational speed exceeds a predetermined speed. A control delays the ignition timing of the engine when the throttle is closed beyond the predetermined position, the engine is not mechanically loaded, and the rotational speed exceeds the predetermined speed.

Abstract: An air-fuel ratio control system for controlling the air-fuel ratio in an internal combustion engine includes an arrangement for switching from open control of the air-fuel ratio to feedback control thereof. A water temperature sensor is provided for detecting the engine water temperature, and a control unit for controlling the air-fuel ratio is also provided. The control unit includes an arrangement for switching from open control to feedback control when the engine water temperature reaches a selected value. The selected value is determined by the control unit in response to a detection signal received from the water temperature sensor at the time the engine is started.

Abstract: An apparatus for supplying an air-fuel mixture through a collecting passage of an intake manifold to a cylinder of an internal combustion engine. The flow of the air-fuel mixture from the intake passageway of a throttle body is discharged transversely into the collecting passageway so that the mixture strikes a region on a side surface of the collecting passageway. Also provided is an arrangement for supplying an auxiliary air stream into the collecting passageway from a location across the striking region from the engine cylinder, which arrangement directs the auxiliary air toward the center of the striking region.

Abstract: A novel method of controlling a continuously variable transmission system by executing sequential steps including delivering a throttle-aperture detection signal and a vehicle-speed detection signal to a controller unit; determining an optimum objective number of engine revolution in reference to a first objective number of engine revolution set by the throttle-aperture detection signal and a second-objective number of engine revolution set by the vehicle-speed detection signal and in accordance with an instruction limiting the number of engine revolution at the shift position; and executing control of the transmission system in response to the vehicle-speed detection signal.

Abstract: There is disclosed a cover unit of an exhaust manifold device in which sound-and-heat shielding covers are attached via bosses to upper and lower parts of exhaust manifold inlet ducts integral with flanges secured to a cylinder head. The cover unit has such a structure that when securing the flanges to the cylinder head, a portion, of a lower cover, on which a tool inserted to rotate bolts for fastening the flanges impinges undergoes a predetermined amount of deformation to admit insertion of the tool.

Abstract: An exhaust-manifold heat insulating board is provided which has an insulating layer sandwiched between an inner layer and an outer layer. The inner and outer layers are laminated together and have an inner area and a peripheral area. The inner area has a depression with end portions formed therein and the peripheral area is formed into connecting tab portions which are positioned adjacent the end portions. Each of the connecting tab portions has a length greater than the width of the adjacent end portion of the depression.

Abstract: An apparatus for controlling a carburetor of a combustion engine includes: a throttle-opening detector switch for detecting that a throttle valve of the carburetor is opened within a predetermined degree of throttle opening; an idle-up mechanism for making the throttle valve perform an idling-up operation; a fuel-cut mechanism for cutting a slow speed fuel supply of the carburetor; and a control unit adapted to allow the idle-up mechanism to perform the idling-up operation under a predetermined load applied to the engine and allow the fuel-cut mechanism to cut the slow speed fuel supply at a reduced speed of the engine when the throttle-opening detector switch detects that the throttle valve of the carburetor is within the predetermined degree of throttle opening. The control unit also includes an arrangement responsive to detection that the throttle valve is not within the predetermined range for inhibiting the idle-up mechanism.

Abstract: A vehicle suction system for reducing the turbulence and pulsation of air flow to an internal combustion engine. A rectifying unit is installed in an air intake passageway of the vehicle suction system so that all air flow through the passageway flows through a face of the rectifying unit. The rectifying unit has a plurality of wedge-shaped partitions alternatingly, inversely disposed in the face of the rectifying unit and separating a plurality of square-shaped holes.

Abstract: A display control apparatus for use in an internal combustion engine includes: a CDI type ignition circuit; an overspeed preventing circuit which can limit the engine speed to a restricted value; a first LED display unit of the light on/off type to display the amounts of oil and/or cooling water; a second LED display unit to display the circulation state of the oil and/or cooling water; and a drive circuit which switches the first and second display units to an alarm display mode and causes the overspeed preventing circuit to limit engine speed when abnormal states of the oil and/or cooling water are detected by oil level switches or by water and oil flow sensors. If power ceases, the display state is held by keep relays. When an abnormal state is detected, the driver is warned by lighting up of red LEDs and by generating a beeping sound from a buzzer.

Abstract: An air-fuel ratio control apparatus for an internal combustion engine supplies an output signal from an O.sub.2 sensor detecting the concentration of oxygen in the exhaust gas to an electronic control unit having a microcomputer, and a control valve of the carburetor is controlled by a control signal from the microcomputer so as to control the air-fuel ratio in a feedback manner. A desired upper limit value is set for the control signal and, when the control signal exceeds this upper limit value in a transient operating condition of the engine, when its operating state is shifted from an idling state to a partial operating state, the microcomputer promptly changes the rich air-fuel ratio to a proper value.

Abstract: An air-distribution apparatus for use with an internal combustion engine, wherein end portions of a plurality of branched air-intake tubes are respectively connected to air-intake holes of respective cylinders of a multiple-cylinder engine. A multiple-barrel carburetor is connected above a mounting assembly unit installed substantially at the center of the plurality of branched air-intake tubes so that each barrel communicates with the intake tubes through a respective air-intake port formed in the top wall of the mounting unit. A primary barrel of the carburetor is disposed in alignment with a transverse centerline of the mounting unit, and a secondary barrel of the carburetor is disposed in a position wherein it is displaced sidewardly from the centerline in the direction of the fuel nozzle tubes which connect to both barrels of the carburetor so as to permit more proper balancing of the air and fuel ratio as supplied to each cylinder.

Abstract: A method of controlling clutch pressure in a continuously variable transmission system which can expand and contract the width of a channel between a stationary pulley member and a movable pulley member movable relative to the stationary pulley member in order to respectively contract and expand a radius of travel about the pulleys of a belt engaging the pulleys before eventually varying a belt ratio, a clutch-pressure control arrangement of the continuously variable transmission system including a controller unit which effects control by feeding an actually-detected clutch pressure back in determining an objective clutch pressure and including an oil-pressure circuit which controls oil pressure in response to signals from the controller unit; the method comprising the step of: causing the controller unit to calculate a clutch duty ratio in reference to the objective clutch pressure and an objective line pressure when a pressure sensor detecting the actually-detected clutch pressure outputs an abnormal signal

Abstract: An intake apparatus for a V-type multiple cylinder engine in which cylinder rows are arranged as a pair and intake ports are disposed to face each other on an inside thereof. The intake apparatus comprises an intake manifold having a collecting section in substantially the central portion of a V-shape arrangement and branches each extending radially from the collecting section. An annular whirling chamber is mounted on the collecting section of the intake manifold and the whirling chamber is provided at the inner peripheral portion with an annular slit in communication with the collecting section. The degree of opening of the slit can be controlled by locating a regulating member such as piston valve for facilitating the atomization and vaporization of the fuel in all operating region. The collecting section may be disposed downwardly in the V-shaped arrangement so that the branches extend upwardly from the collecting section, whereby the overall height of the engine is reduced.

Abstract: A breather apparatus for four-cycle engines of the overhead cam type for two-wheeled motorcycles in which a cam chain for driving an operational valve cam is suspended in a cam chain chamber formed so as to vertically penetrate the cylinder block. The cam chain chamber is arranged at a position which is slightly deviated in one direction perpendicular to the crank shaft. A breather chamber adjacent to the cam chain chamber is formed in the cylinder block in the opposite direction and is connected to a breather hole which opens to the upper portion of the cylinder head. An adjuster apparatus elastically contacts the back side of a chain tensioner to create a tension in the cam chain, and is disposed in a space in the cylinder block. The adjuster apparatus has a backward motion-preventing mechanism which is urged by a spring force so as to always push the chain tensioner. The backward motion of this mechanism is prevented and can be released by a screw member.

Abstract: A diagnosis system has a diagnosis switch, and has a controller actuated by the switch for checking the operation of sensors and circuits and for lighting an alarm lamp in accord with a coded lighting signal, the number of times the alarm lamp is lit indicating the result of the diagnosis. The diagnosis switch includes a pair of diagnosis terminals which are similar to a pair of fuse terminals and are provided in a fuse box or in a joint box having a fuse box, and includes a spare fuse which can be inserted into the diagnosis terminals so as to produce a signal to the controller for starting the diagnosis.