Abstract: An air-cleaner structure of a saddle-ride vehicle is provided with an air-cleaner case arranged between a seat and a head pipe located in front of the seat. The air-cleaner case is provided with a bottom half and a top half. The bottom half is arranged in a space surrounded by a rear face of the head pipe and a pair of left and right main frames extending from the head pipe toward the rear of the vehicle. The top half is situated above the main frames. The top half is provided in a vertical two division structure. A dividing surface of the vertical two division structure of the top half is inclined in the vehicle-longitudinal direction. An air-cleaner element is mounted along the inclined dividing surface.

Abstract: An air-cleaner structure of a saddle-ride vehicle is provided with an air-cleaner case arranged between a seat and a head pipe located in front of the seat. The air-cleaner case is provided with a bottom half and a top half. The bottom half is arranged in a space surrounded by a rear face of the head pipe and a pair of left and right main frames extending from the head pipe toward the rear of the vehicle. The top half is situated above the main frames. The top half is provided in a vertical two division structure. A dividing surface of the vertical two division structure of the top half is inclined in the vehicle-longitudinal direction. An air-cleaner element is mounted along the inclined dividing surface.

Abstract: A compact air cleaner device with a secure intake capacity. An internal combustion engine includes the air cleaner device mounted on a vehicle body frame. The air cleaner device includes an air cleaner case having a filter element therein, and being partitioned into a dirty side chamber and a clean side chamber with a plurality of intake ducts for leading an outside air into the dirty side chamber, the intake ducts being provided so as to form a left-right pair. The intake ducts have intake ports opened outside side portions of the air cleaner case. Paths of the intake ducts leading to discharge ports are housed within the dirty side chamber with bent portions. The discharge ports of the intake ducts forming the left-right pair are disposed so as to be oriented to a central side of the air cleaner case and offset from each other in a forward-rearward direction.

Abstract: An air cleaner device includes an air cleaner case having a case main unit and a cover. An intake duct is disposed on the cover, and an intake path is disposed on the case main unit. An air cleaner element is formed in a position biased on a side of the cover relative to fastening surfaces of the case main unit and the cover. The cover and the air cleaner element are integrally removable relative to the case main unit.

Abstract: A compact air cleaner device with a secure intake capacity. An internal combustion engine includes the air cleaner device mounted on a vehicle body frame. The air cleaner device includes an air cleaner case having a filter element therein, and being partitioned into a dirty side chamber and a clean side chamber with a plurality of intake ducts for leading an outside air into the dirty side chamber, the intake ducts being provided so as to form a left-right pair. The intake ducts have intake ports opened outside side portions of the air cleaner case. Paths of the intake ducts leading to discharge ports are housed within the dirty side chamber with bent portions. The discharge ports of the intake ducts forming the left-right pair are disposed so as to be oriented to a central side of the air cleaner case and offset from each other in a forward-rearward direction.

Abstract: An air cleaner device can include an air cleaner case including a case main unit and a cover. An intake duct can be disposed on the cover, and an intake path can be disposed on the case main unit. An air cleaner element can be accommodated in the air cleaner case. When the air cleaner device is mounted in a vehicle and viewed from a vehicle side, the air cleaner case is formed to be vertically long. The intake duct is formed to have an upstream-side opening portion thereof oriented toward a first side of the air cleaner case, and a downstream-side opening portion thereof can be oriented downwardly. The intake path is formed to have an upstream-side opening portion thereof oriented upwardly to face the downstream-side opening portion of the intake duct, and a downstream-side opening portion thereof is oriented toward a second side of the air cleaner case.

Abstract: An internal combustion engine includes an intake passage structure. The engine is configured such that a cylinder head is formed integrally with an intake manifold portion. A cylinder central axis is oriented parallel to an extending direction of an intake passage, when viewed in a side view. An injector is arranged such that it does not interfere with peripheral components, including the intake passage and a throttle body. The injector is disposed in the intake manifold portion such that a leading end thereof is oriented towards the intake valve of the cylinder head. The intake passage on the upstream side of an injector attachment position is offset from the injector in a width-direction of the internal combustion engine.

Abstract: An air cleaner device includes an air cleaner case having a case main unit and a cover. An intake duct is disposed on the cover, and an intake path is disposed on the case main unit. An air cleaner element is formed in a position biased on a side of the cover relative to fastening surfaces of the case main unit and the cover. The cover and the air cleaner element are integrally removable relative to the case main unit.

Abstract: An air cleaner device can include an air cleaner case including a case main unit and a cover. An intake duct can be disposed on the cover, and an intake path can be disposed on the case main unit. An air cleaner element can be accommodated in the air cleaner case. When the air cleaner device is mounted in a vehicle and viewed from a vehicle side, the air cleaner case is formed to be vertically long. The intake duct is formed to have an upstream-side opening portion thereof oriented toward a first side of the air cleaner case, and a downstream-side opening portion thereof can be oriented downwardly. The intake path is formed to have an upstream-side opening portion thereof oriented upwardly to face the downstream-side opening portion of the intake duct, and a downstream-side opening portion thereof is oriented toward a second side of the air cleaner case.

Abstract: An internal combustion engine includes an intake passage structure. The engine is configured such that a cylinder head is formed integrally with an intake manifold portion. A cylinder central axis is oriented parallel to an extending direction of an intake passage, when viewed in a side view. An injector is arranged such that it does not interfere with peripheral components, including the intake passage and a throttle body. The injector is disposed in the intake manifold portion such that a leading end thereof is oriented towards the intake valve of the cylinder head. The intake passage on the upstream side of an injector attachment position is offset from the injector in a width-direction of the internal combustion engine.

Abstract: A lubricating structure for an engine includes a crankcase for supporting a crankshaft formed from a pair of case halves coupled to each other along a mating plane extending along a plane perpendicular to an axial line of the crankshaft. An oil reservoir in a lower portion of the crankcase extends across the mating plane. A pump chamber of an oil pump is formed between the two case halves across the mating plane. Lubricant is drawn from the oil reservoir into the oil pump using a structure which can achieve reduction of the number of parts and improve the ease of assembly. The structure includes a path groove, which forms an oil suction path for interconnecting the oil pump and the oil reservoir, formed in at least one of the two case halves.

Abstract: In an engine starting unit, a gear switching clutch is fitted on one end of a main shaft, a power transmission gear train including a clutch gear rotating together with an input member of the gear switching clutch is provided between one end of a crankshaft and the input member, a kick start gear train is arranged between a drive gear group and the clutch gear, and a one-way starter clutch is arranged on the crankshaft between the drive gear group and the clutch gear.

Abstract: A cylinder block, a cylinder head and a cylinder head cover are stacked in order to form a four-cycle engine. A valve train of a single overhead camshaft (SOHC) type provided with an intake valve and an exhaust valve is provided in the cylinder head. A line extending parallel with a joint between the cylinder head and the cylinder head cover is inclined forward and downward toward a line parallel with a joint between the cylinder block and the cylinder head. An axis of an exhaust valve and/or an axis of a plug tube is/are perpendicular to the line extending parallel with the joint between the cylinder head and the cylinder head cover. A cylinder head hanger is integrally formed at an uppermost end of a rear portion of the cylinder head over an intake port.

Abstract: A decompression device is provided for an internal combustion engine having a cylinder head provided with a pair of left and right camshaft bearings sandwiching intake valves and exhaust valves with a structure that is both simple and small. A camshaft is provided having cam projections for at least a pair of intake cams between camshaft side bearings corresponding to the pair of left and right bearings, and a decompression member with a decompression cam with a centrifugal weight arranged at a camshaft end passing through the bearing close to the camshaft end so that a tip thereof is arranged in the vicinity of the cam projections, with the decompression member comprising the centrifugal weight, the decompression cam, and a rotatable shaft coupling the centrifugal weight and the decompression cam in an integral manner.

Abstract: A lubricating structure for an engine includes a crankcase for supporting a crankshaft formed from a pair of case halves coupled to each other along a mating plane extending along a plane perpendicular to an axial line of the crankshaft. An oil reservoir in a lower portion of the crankcase extends across the mating plane. A pump chamber of an oil pump is formed between the two case halves across the mating plane. Lubricant is drawn from the oil reservoir into the oil pump using a structure which can achieve reduction of the number of parts and improve the ease of assembly. The structure includes a path groove, which forms an oil suction path for interconnecting the oil pump and the oil reservoir, formed in at least one of the two case halves.

Abstract: A decompression device is provided for an internal combustion engine having a cylinder head provided with a pair of left and right camshaft bearings sandwiching intake valves and exhaust valves with a structure that is both simple and small. A camshaft is provided having cam projections for at least a pair of intake cams between camshaft side bearings corresponding to the pair of left and right bearings, and a decompression member with a decompression cam with a centrifugal weight arranged at a camshaft end passing through the bearing close to the camshaft end so that a tip thereof is arranged in the vicinity of the cam projections, with the decompression member comprising the centrifugal weight, the decompression cam, and a rotatable shaft coupling the centrifugal weight and the decompression cam in an integral manner.

Abstract: In an engine starting unit, a gear switching clutch is fitted on one end of a main shaft, a power transmission gear train including a clutch gear rotating together with an input member of the gear switching clutch is provided between one end of a crankshaft and the input member, a kick start gear train is arranged between a drive gear group and the clutch gear, and a one-way starter clutch is arranged on the crankshaft between the drive gear group and the clutch gear.

Abstract: A cylinder block, a cylinder head and a cylinder head cover are stacked in order to form a four-cycle engine. A valve train of a single overhead camshaft (SOHC) type provided with an intake valve and an exhaust valve is provided in the cylinder head. A line extending parallel with a joint between the cylinder head and the cylinder head cover is inclined forward and downward toward a line parallel with a joint between the cylinder block and the cylinder head. An axis of an exhaust valve and/or an axis of a plug tube is/are perpendicular to the line extending parallel with the joint between the cylinder head and the cylinder head cover. A cylinder head hanger is integrally formed at an uppermost end of a rear portion of the cylinder head over an intake port.