Abstract: A spark ignition type engine adjusts a base lower limit value of a valve opening degree of an ISC valve to avoid excessive engine rotation that may occur when an increase correction by atmospheric pressure is performed. When a detected engine temperature becomes lower, the base lower limit value of the ISC valve opening degree is increased to the fully open side, and the base lower limit value is corrected to increase to the fully open side with an increase correction value on the basis of a detected atmospheric pressure in an engine middle-high temperature range where the engine temperature exceeds a predetermined value, and the increase correction value is increased to the fully open side as the detected atmospheric pressure becomes lower, and the increase correction is prohibited in an engine low temperature range where the engine temperature is equal to or lower than the predetermined value.

Abstract: An engine-equipped vehicle capable of preventing gear noise and gear wear when the engine is started is provided. A multicylinder engine, a gear transmission that shifts power from the multicylinder engine by a shift operation, a centrifugal clutch arranged in a power transmission path from the multicylinder engine to the gear transmission, and an electronic control device that controls an operation of the multicylinder engine are included and the engine is configured to be started with a partial cylinder operation start where under control of the electronic control device, only some cylinders are operated and an operation of other cylinders is stopped.

Abstract: A spark ignition type engine enabling engine startability to be favorable is provided. The spark ignition type engine includes a main intake-air passage; a throttle valve of the main intake-air passage; a bypass intake-air passage bypassing the throttle valve; an ISC valve of the bypass intake-air passage; and an electronic control device that controls an engine speed by adjusting an opening degree of the ISC valve, in which when the engine is started, cranking is performed at a cranking opening degree at which the ISC valve is narrowed by a predetermined amount from a fully opened state by control of the electronic control device, so that an intake-air negative pressure is generated on an intake-air downstream side of the ISC valve.

Abstract: A spark ignition type engine adjusts a base lower limit value of a valve opening degree of an ISC valve to avoid excessive engine rotation that may occur when an increase correction by atmospheric pressure is performed. When a detected engine temperature becomes lower, the base lower limit value of the ISC valve opening degree is increased to the fully open side, and the base lower limit value is corrected to increase to the fully open side with an increase correction value on the basis of a detected atmospheric pressure in an engine middle-high temperature range where the engine temperature exceeds a predetermined value, and the increase correction value is increased to the fully open side as the detected atmospheric pressure becomes lower, and the increase correction is prohibited in an engine low temperature range where the engine temperature is equal to or lower than the predetermined value.

Abstract: A spark ignition type engine enabling engine startability to be favorable is provided. The spark ignition type engine includes a main intake-air passage; a throttle valve of the main intake-air passage; a bypass intake-air passage bypassing the throttle valve; an ISC valve of the bypass intake-air passage; and an electronic control device that controls an engine speed by adjusting an opening degree of the ISC valve, in which when the engine is started, cranking is performed at a cranking opening degree at which the ISC valve is narrowed by a predetermined amount from a fully opened state by control of the electronic control device, so that an intake-air negative pressure is generated on an intake-air downstream side of the ISC valve.

Abstract: A port injection engine, in which injected fuel readily vaporizes inside suction ports, includes: a suction port; a suction valve; and a port injector that injects fuel to an inner peripheral surface of the suction port. When the fuel is burned in a predetermined combustion cycle, an injection start of a fuel injection period is set within an end part of a valve opening period before the suction valve is fully closed, during a combustion cycle previous to the predetermined combustion cycle. The end part of the valve opening period is preferably set from 50° to 20° before the suction valve is fully closed at a crank angle.

Abstract: An engine-equipped vehicle capable of preventing gear noise and gear wear when the engine is started is provided. A multicylinder engine, a gear transmission that shifts power from the multicylinder engine by a shift operation, a centrifugal clutch arranged in a power transmission path from the multicylinder engine to the gear transmission, and an electronic control device that controls an operation of the multicylinder engine are included and the engine is configured to be started with a partial cylinder operation start where under control of the electronic control device, only some cylinders are operated and an operation of other cylinders is stopped.

Abstract: A port injection engine, in which injected fuel readily vaporizes inside suction ports, includes: a suction port; a suction valve; and a port injector that injects fuel to an inner peripheral surface of the suction port. When the fuel is burned in a predetermined combustion cycle, an injection start of a fuel injection period is set within an end part of a valve opening period before the suction valve is fully closed, during a combustion cycle previous to the predetermined combustion cycle. The end part of the valve opening period is preferably set from 50° to 20° before the suction valve is fully closed at a crank angle.

Abstract: In a cylinder head cooling structure of engine E including a camshaft 15 rotated by a crankshaft 2, a push rod, and an actuatable rocker arm, an injection hole 46 for injecting oil pressurized by an oil pump 44 is formed in a shaft portion 43 between an exhaust cam 36 on the camshaft 15 and a journal 15j at its rear end, and the oil injected the injection hole 46 is allowed to enter a rear cylinder head cover 7 through a pushrod chamber in which the push rod is disposed.

Abstract: An exhaust purifying apparatus is provided, that can be manufactured at low manufacturing costs and is capable exhibiting high exhaust purifying performance. The exhaust purifying apparatus includes an exhaust passage, and an exhaust purifying member disposed in the exhaust passage. The exhaust purifying member is made of stainless steel. The surface of the stainless steel material is not covered with a catalyst coat containing a catalyst component, so that the surface of the stainless steel material is brought into contact with exhaust. The exhaust purifying member is made of precipitation hardening stainless steel and/or austenitic stainless steel.

Abstract: An exhaust purifying apparatus is provided, that can be manufactured at low manufacturing costs and is capable exhibiting high exhaust purifying performance. The exhaust purifying apparatus includes an exhaust passage, and an exhaust purifying member disposed in the exhaust passage. The exhaust purifying member is made of stainless steel. The surface of the stainless steel material is not covered with a catalyst coat containing a catalyst component, so that the surface of the stainless steel material is brought into contact with exhaust. The exhaust purifying member is made of precipitation hardening stainless steel and/or austenitic stainless steel.

Abstract: In a cylinder head cooling structure of engine E including a camshaft 15 rotated by a crankshaft 2, a push rod, and an actuatable rocker arm, an injection hole 46 for injecting oil pressurized by an oil pump 44 is formed in a shaft portion 43 between an exhaust cam 36 on the camshaft 15 and a journal 15j at its rear end, and the oil injected the injection hole 46 is allowed to enter a rear cylinder head cover 7 through a pushrod chamber in which the push rod is disposed.