Abstract: A drysump lubrication type engine is integrally connected at a crankcase thereof with an oil tank. A magnet coil coaxially mounted on an extension line of a crankshaft is covered by the oil tank and accommodated between the oil tank and the engine.

Abstract: An engine starter includes a recoil device, and a recoil cover for accommodating the recoil device therein also covers a flywheel operatively rotated with the recoil device, ring gears integrally fixed to the flywheel, and pinions which are components of a starter device and engage with the ring gears when the starter device is operated. The recoil cover is provided with a drain mechanism, including a boss formed integrally with the recoil cover, a drain pipe projected on the boss, and a drain cap plugged to the drain pipe and made of rubber so that it is manually detachable therefrom without using a tool. Thus a liquid such as muddy water which has entered from the recoil cover can be removed simply by pulling out the drain cap.

Abstract: A drysump lubrication type engine is integrally connected at a crankcase thereof with an oil tank. A magnet coil coaxially mounted on an extension line of a crankshaft is covered by the oil tank and accommodated between the oil tank and the engine.

Abstract: An engine starter includes a recoil device, and a recoil cover for accommodating the recoil device therein also covers a flywheel operatively rotated with the recoil device, ring gears integrally fixed to the flywheel, and pinions which are components of a starter device and engage with the ring gears when the starter device is operated. The recoil cover is provided with a drain mechanism, including a boss formed integrally with the recoil cover, a drain pipe projected on the boss, and a drain cap plugged to the drain pipe and made of rubber so that it is manually detachable therefrom without using a tool. Thus a liquid such as muddy water which has entered from the recoil cover can be removed simply by pulling out the drain cap.

Abstract: A separate oiling type two cycle engine having a diaphragm type float-less carburetor including a metering chamber and a needle valve comprises a fuel reservoir for reserving fuel, a fuel supply port provided at the fuel reservoir for supplying fuel into the fuel reservoir, a fuel passage for connecting the fuel reservoir with the needle valve, a venturi provided immediately upstream of the needle valve, an oil discharge port provided adjacent to the inlet of the venturi for discharging lubricating oil therethrough so as to mix lubricating oil with fuel, and a fuel return port provided at the higher position than the fuel supply port for returning fuel to a fuel tank. Since lubricating oil is supplied to almost all major components of the carburetor, carburetor components such as a choke valve, a throttle valve, fuel passages, jets, metering needles, nozzles and the like can be prevented from being corroded, rusted or clogged by salt water contained in fuel.

Abstract: A pressure sensor is provided in a fuel supply line for detecting fuel pressure for generating a pressure signal. The pressure signal is compared with a predetermined pressure value dependent on operating conditions of an engine. Amount of fuel injected into the engine is decreased when the pressure signal is higher than the predetermined pressure value, or the amount of fuel is increased when the pressure signal is lower than the predetermined pressure value for effectively preventing the engine from damaging.

Abstract: A first fuel injection pulse width is provided based on engine operating conditions. The amount of fuel is necessary for one combustion stroke of the engine at one time. A second fuel injection pulse width is provided based on engine operating conditions so as to inject at one time an amount of fuel for two combustion strokes of the engine. The first fuel injection pulse width is compared with a minimum value. The first fuel injection pulse width is selected when the first fuel injection pulse width is larger than the minimum value, and otherwise, the second fuel injection pulse width is selected when the first fuel injection pulse width is smaller than the minimum value. Fuel is injected at the selected injection pulse.

Abstract: A snowmobile has an upper hood having a plurality of air intakes, an engine provided downstream of the air intakes, and an air box having an air cleaner and communicating with an inlet port of the engine. An electronic control unit is disposed in a case which is secured to an upper wall of the air box. A deflector is disposed between the air intakes and the case so as to deflect intake air from the case.

Abstract: An idling speed adjustment system for an engine, in which a pulse width for corrected fuel injection in the idling operation of the engine is set by adjusting idling adjustment means adapted to be adjusted from outside the system. Subsequently, a pulse width for fuel injection in the idling operation is determined in such a way that a pulse width for basic fuel injection which is set on the basis of a throttle opening degree and engine speed is corrected with several correction values which are set on the basis of detected engine state parameters, and the idling-operation corrected fuel injection pulse width which is set as described above.

Abstract: An ignition device intermittently produces an ignition voltage in synchronism with speed of an engine. A fuel injection control is provided for operating a fuel injector for injecting fuel. A fuel pump for supplying fuel to the fuel injector is stopped at a time after the ignition and fuel injection stop, thereby keeping fuel pressure in a fuel supply passage.

Abstract: A crankcase temperature sensor is provided for detecting temperature of a crankcase. A low speed basic injection pulse width is provided based on the detected crankcase temperature for low engine speed. An ordinary fuel injection pulse width is provided in accordance with engine operating conditions for ordinary engine operating condition. A comparator is provided for comparing the low speed injection pulse width and the ordinary fuel injection pulse width with each other. A larger injection pulse width is determined for injecting fuel.

Abstract: A motor vehicle has a continuously variable belt-drive transmission having a clutch means which engages when speed of an engine is higher than a clutch engaging speed. A plurality of basic pulse widths for injecting fuel are stored in a memory arranged in accordance with the engine speed and opening degree of a throttle valve. Some of the basic pulse widths in a speed range lower than the clutch engaging engine speed are increased for acceleration of the engine. One of the basic pulse widths is retrieved in accordance with the actual engine speed and the throttle valve opening degree, and a fuel injection pulse width is calculated based on the retrieved basic pulse width.

Abstract: Disclosed is a system for controlling the fuel injection quantity at the start of a two-cycle engine, in which a predetermined amount of a fuel is preliminarily injected when a key switch of the engine is turned on, the revolution speed of the engine is smaller than a reference value and the opening degree of a throttle valve takes a predetermined change pattern.

Abstract: A two-cycle engine has an lubricating system for lubricating rubbing parts in a crankcase. A fuel injector is provided on a wall of an intake passage for injecting fuel toward an intake port of the engine. An oil injecting port is formed in the wall of the intake passage, and the fuel injector is provided for injecting fuel toward the port so as to mix with the lubricating oil.

Abstract: A two-cycle engine with fuel injector comprises an engine body, a crank case defining crank chambers for respective cylinders, the crank chambers being provided with intake ports, throttle bodies, and fuel injectors. The throttle bodies comprise throttle passages and throttle valve means and the injectors are inserted in the throttle passages downstream of the throttle valve means. The throttle passages are connected to each other through a balance passage at portions downstream the throttle valve means. An air chamber may be formed on the way of the balance passage. The throttle passages connected by the balance passage to one group of cylinders having phase difference of 180.degree. of the reciprocating stroke.

Abstract: A two-cycle engine has a balancer shaft driven by a crankshaft of the engine through gears, and a gear cover forming a balancer gear chamber for the gears. The balancer gear chamber is communicated with the atmosphere through a breather passage formed in an upper portion thereof. A labyrinth passage is formed in the balancer gear chamber for breathing air, so as to separate oil from discharging air.

Abstract: An air-fuel ratio control system for a two-cycle engine is disclosed, which includes a cylinder, a crank case serving also as a pressure chamber, a fuel injection unit including an injector and a pump, an engine speed detecting element for detecting the engine speed, and a throttle opening degree detecting element for detecting the opening degree of a throttle valve.