A straddled vehicle engine unit including an internal combustion engine and a misfire detection device. The internal combustion engine has a crankshaft, and a crank angle signal output unit that periodically outputs a crank angle signal in accordance with rotation of the crankshaft. The internal combustion engine is configured to repeat at least two kinds of strokes on a cycle of every 720-degree rotation of the crankshaft. The misfire detection device includes a crankshaft rotation speed fluctuation physical quantity acquisition unit configured to acquire a physical quantity related to an amount of fluctuation in a rotation speed of the crankshaft in one kind of stroke, out of the at least two kinds of strokes, based on the crank angle signal from the crank angle signal output unit, and a misfire determination unit configured to perform a misfire determination in response to each acquisition of the crankshaft rotation speed fluctuation physical quantity.

A straddled vehicle engine unit including an internal combustion engine and a misfire detection device. The internal combustion engine has a crankshaft, and a crank angle signal output unit that periodically outputs a crank angle signal in accordance with rotation of the crankshaft. The internal combustion engine is configured to repeat at least two kinds of strokes on a cycle of every 720-degree rotation of the crankshaft. The misfire detection device includes a crankshaft rotation speed fluctuation physical quantity acquisition unit configured to acquire a physical quantity related to an amount of fluctuation in a rotation speed of the crankshaft in one kind of stroke, out of the at least two kinds of strokes, based on the crank angle signal from the crank angle signal output unit, and a misfire determination unit configured to perform a misfire determination in response to each acquisition of the crankshaft rotation speed fluctuation physical quantity.

The objective is to improve driving feeling at a time of acceleration operation or deceleration operation, by recognizing driver's intention of acceleration or deceleration during straight-ahead running. A driving-assistance control apparatus according to the present disclosure includes a straight-running determination unit that determines whether or not a vehicle is running straight, a head-position detection unit that detects a head position of a driver, a driving-posture determination unit that determines the posture of the driver, based on the head position detected by the head-position detection unit, and a driving-assistance control unit that performs acceleration preparation control for raising a reaction speed for acceleration operation or deceleration preparation control for raising a reaction speed for deceleration operation in accordance with an output of the driving-posture determination unit, when the straight-running determination unit determines that a vehicle is running straight.

A vehicle includes at least one of an electric vent valve configured to open and close an outside-air-introduction passage of a canister or an electric suction pump configured. to suck gas in a gas passage through which the gas flows. The canister and at least one of the vent valve or the suction pump are disposed such that at least one of a virtual-left-right-center plane that includes a center in a left-right direction and is perpendicular to the left-right direction, a virtual-front-rear-center plane that includes a center in a front-rear direction and is perpendicular to the front-rear direction, or a virtual-up-down-center plane that includes a center in an up-down direction and is perpendicular to the up-down direction is located between a gravity center of the canister and at least one of a gravity center of the vent valve or a gravity center of the suction pump.

A balanced motorcycle powertrain is described. Embodiments of the balanced motorcycle powertrain include components mounted to a frame of a motorcycle such that the powertrain can be evenly balanced about a centerline of the frame. The balanced motorcycle powertrain can include, but is not limited to, a motor, a transmission, a pair of clutches, a clutch shaft, a crank shaft, a pair of superchargers, a pair of chains, a pair of rear sprockets, and a rear wheel. Each of the components can be oriented such that the powertrain is substantially balanced about the centerline of the frame.

A balanced motorcycle powertrain is described. Embodiments of the balanced motorcycle powertrain include components mounted to a frame of a motorcycle such that the powertrain can be evenly balanced about a centerline of the frame. The balanced motorcycle powertrain can include, but is not limited to, a motor, a transmission, a pair of clutches, a clutch shaft, a crank shaft, a pair of superchargers, a pair of chains, a pair of rear sprockets, and a rear wheel. Each of the components can be oriented such that the powertrain is substantially balanced about the centerline of the frame.

A saddle-riding vehicle includes a radiator in front of an engine of the saddle-riding vehicle and on one lateral side of the vehicle in a vehicle widthwise direction with respect to a center line in the vehicle widthwise direction. The radiator includes: a radiator body that allows coolant of the engine to flow through the radiator body; a radiator fan at a rear face of the radiator body; and a fan cover that covers the radiator fan from a rear of the radiator fan to guide exhaust air from the radiator to the one lateral side in the vehicle widthwise direction.

In a saddle-ride vehicle including an engine, and a component disposed near the engine, a member is disposed between the engine and the component, and the member is a resistor that is one of the components of the saddle-ride vehicle.

A rear drive transmission system for a motorcycle includes a driving wheel, a center wheel, and a driven wheel. The center wheel includes a transmission wheel A and a transmission wheel B that are coaxially arranged. The transmission wheel A is fixedly connected to an opposite surface of the transmission wheel B. The driving wheel is drivingly connected to the transmission wheel B. The transmission wheel A is drivingly connected to the driven wheel, and the driving wheel is detachably and fixedly connected to an output shaft of a motor or engine. The driven wheel is detachably connected with a rear wheel shaft of the motorcycle. The center wheel is rotatably connected with a rear fork rotation center shaft through a bearing. The motorcycle is with the motorcycle rear drive transmission system.

A straddle type electric vehicle comprises a main frame, a motor unit including an electric motor, and a battery that supplies power to the motor unit. The main frame includes a left and right pair of portions. The motor unit is disposed overlapping the main frame in a side view of the vehicle. A motor shaft of the electric motor is disposed above the pivot shaft and rearward in the vehicle longitudinal direction.