Abstract: An intake duct structure of a motorcycle includes front forks disposed on both of right and left sides of a head pipe of a body frame and a main frame extending obliquely backward and downward from the head pipe, wherein the intake duct structure extends from a front end of the motorcycle toward the head pipe and is formed in such a manner that an interfered area where a rotational orbit of the front forks at a time of steering overlaps the intake duct structure is elastically deformable.

Abstract: An intake duct structure of a motorcycle includes front forks disposed on both of right and left sides of a head pipe of a body frame and a main frame extending obliquely backward and downward from the head pipe, wherein the intake duct structure extends from a front end of the motorcycle toward the head pipe and is formed in such a manner that an interfered area where a rotational orbit of the front forks at a time of steering overlaps the intake duct structure is elastically deformable.

Abstract: The configuration includes: a right and left pair of main frames extending from a head pipe while widening rearward; and pivot frames that are welded to the main frames and extend toward the rear downward direction. Under the main frames, an engine is arranged. The main frame includes a hanging portion for holding and fastening the engine. In the front portion of the main frame, a bulge portion is disposed on the vehicle-widthwise outer side. The hanging portion is settable to the bulge portion.

Abstract: A secondary injector that is one of a plurality of injectors provided for each cylinder is arranged in an air cleaner and above an air funnel, and the secondary injector and the air funnel facing the secondary injector are arranged to be inclined such that a base portion of the secondary injector on an outer side in a vehicle width direction is biased to a center side in the vehicle width direction and an injection port thereof is directed to a throttle body.

Abstract: There is provided a swing arm for a motorcycle. A base section is connected to a chassis framework via a pivot member. A pair of rear-arm sections extend rearwards from the base section. A pair of bracket sections are respectively provided at rear end portions of the rear-arm sections to rotatably support a rear wheel. Each of the bracket sections is formed into a shape including a hole through which an axle of the rear wheel passes, an engaging plane formed at a region surrounding the hole, and a peripheral formation plane positioned to connect with the outer periphery of the rear-arm sections. An inner surface of the peripheral formation plane in the width direction is formed so as to be inclined outwards in the width direction from a side of formation region of the hole towards a front side as viewed from the top.

Abstract: An engine is mounted on a body frame extending from a steering head pipe toward a vehicle rear side slightly downward and an air cleaner is disposed above the engine. An intake duct device includes an intake duct which leads traveling air taken from a front surface of a cowling to the air cleaner so as to make the traveling air pass along both side surfaces of the steering head pipe. The intake duct is made of a separate component from the body frame, is two-divided into a front intake duct and a rear intake duct so as to surround the steering head pipe from front and rear sides, and is fixed to the body frame by fastening.

Abstract: An opening of an upper surface of an air cleaner main body has an air cleaner upper cover mounted thereon, and is closed by the air cleaner upper cover fastened by bolts via a seal member, and air cleaner bottom plates are fastened to the air cleaner main body via seal members in openings of a bottom surface of the air cleaner main body. Passage holes connecting an engine combustion chamber and the air cleaner main body are provided on the air cleaner bottom plates; and an opening of a front surface of the air cleaner main body is inserted into intake ducts of vehicle body frames via seal members, and configured as an air introduction port.

Abstract: The configuration includes: a right and left pair of main frames extending from a head pipe while widening rearward; and pivot frames that are welded to the main frames and extend toward the rear downward direction. Under the main frames, an engine is arranged. The main frame includes a hanging portion for holding and fastening the engine. In the front portion of the main frame, a bulge portion is disposed on the vehicle-widthwise outer side. The hanging portion is settable to the bulge portion.

Abstract: A part of an air cleaner main body overlapped with vehicle body frames in a side view has a shape in which an upper surface portion of the part is narrower than a bottom surface portion of the part. The air cleaner main body is formed to have approximately uniform gaps along inner surfaces of the vehicle body frames, and the air cleaner main body is inserted from a position below the vehicle body frames and is fixed to the vehicle body frames before mounting an engine.

Abstract: An engine is mounted on a body frame extending from a steering head pipe toward a vehicle rear side slightly downward and an air cleaner is disposed above the engine. An intake duct device includes an intake duct which leads traveling air taken from a front surface of a cowling to the air cleaner so as to make the traveling air pass along both side surfaces of the steering head pipe. The intake duct is made of a separate component from the body frame, is two-divided into a front intake duct and a rear intake duct so as to surround the steering head pipe from front and rear sides, and is fixed to the body frame by fastening.

Abstract: There is provided a swing arm for a motorcycle. A base section is connected to a chassis framework via a pivot member. A pair of rear-arm sections extend rearwards from the base section. A pair of bracket sections are respectively provided at rear end portions of the rear-arm sections to rotatably support a rear wheel. Each of the bracket sections is formed into a shape including a hole through which an axle of the rear wheel passes, an engaging plane formed at a region surrounding the hole, and a peripheral formation plane positioned to connect with the outer periphery of the rear-arm sections. An inner surface of the peripheral formation plane in the width direction is formed so as to be inclined outwards in the width direction from a side of formation region of the hole towards a front side as viewed from the top.

Abstract: A secondary injector that is one of a plurality of injectors provided for each cylinder is arranged in an air cleaner and above an air funnel, and the secondary injector and the air funnel facing the secondary injector are arranged to be inclined such that a base portion of the secondary injector on an outer side in a vehicle width direction is biased to a center side in the vehicle width direction and an injection port thereof is directed to a throttle body.

Abstract: A secondary injector that is one of a plurality of injectors provided for each cylinder is arranged in an air cleaner and above an air funnel, an air cleaner bottom plate that has a passage hole for forming an intake passage is fastened and fixed to an upper surface of a throttle body, and the air funnel and a pipe support post for a secondary delivery pipe are fastened and fixed to the air cleaner bottom plate.

Abstract: An opening of an upper surface of an air cleaner main body has an air cleaner upper cover mounted thereon, and is closed by the air cleaner upper cover fastened by bolts via a seal member, and air cleaner bottom plates are fastened to the air cleaner main body via seal members in openings of a bottom surface of the air cleaner main body. Passage holes connecting an engine combustion chamber and the air cleaner main body are provided on the air cleaner bottom plates; and an opening of a front surface of the air cleaner main body is inserted into intake ducts of vehicle body frames via seal members, and configured as an air introduction port.

Abstract: A part of an air cleaner main body overlapped with vehicle body frames in a side view has a shape in which an upper surface portion of the part is narrower than a bottom surface portion of the part. The air cleaner main body is formed to have approximately uniform gaps along inner surfaces of the vehicle body frames, and the air cleaner main body is inserted from a position below the vehicle body frames and is fixed to the vehicle body frames before mounting an engine.