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.

A vehicle includes an engine unit, a radiator, a first passage, and a second passage which is provided below the cylinder head and to which lubricating liquid is supplied. The radiator is arranged in front of the engine unit. The first passage includes a first opening arranged in front of the radiator so as to face the radiator and is configured to guide first traveling wind from the first opening toward the radiator. The second passage includes a second opening arranged outside the first opening in the vehicle width while being partitioned from the first opening, and is configured to guide second traveling wind from the second opening toward the lower supplied member.

A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.

There is provided a radiator fan configured to introduce outside air into a radiator in front of an engine. The radiator fan includes: a propeller disposed behind the radiator; a fan motor configured to drive the propeller to rotate; and a fan shroud covering the propeller from behind. The fan shroud is formed with a plurality of hoods whose exhaust air ports are directed in any directions in a range from a lateral direction to a downward direction.

An engine unit includes a cylinder, a crankshaft, a crankcase, a generator, a sensor, and a coolant passage. The crankshaft is connected to a piston in the cylinder. The crankcase accommodates the crankshaft therein. The generator includes a rotor that rotates together with the crankshaft and a stator facing the rotor. The generator generates electric power by rotation of the rotor. The sensor detects a rotation position of the rotor. The coolant passage includes an ejection port, guides a coolant to the ejection port, and ejects the coolant from the ejection port toward the sensor.

Conveyance vehicles such as snow bikes and snowmobiles having an endless track system driven by a combustion engine are enhanced in performance with a torque assist system. The torque assist system includes an electric motor that is coupled to drive the track in parallel with the original internal combustion engine through either its own track drive, or through the drive system of the engine. The motor can be a spindle drive motor or hub motor. Torque assist is generated through a torque assist throttle input coupled to a motor controller. A battery temperature assist system diverts heated cooling fluid from the engine cooling system to heat the battery through its own heat exchanger. The controller is coupled to a processing device such as a smart phone that executes apps configured to provide parametric data to the controller and to receive parametric data from the controller through a user interface.

A straddled vehicle having an engine unit. The engine unit includes an engine body having a cylinder axis tilting forward, a radiator including a radiator core, a turbocharger including a turbine wheel and a compressor wheel, and an intercooler including an intercooler core. In a side view, at least a part of the intercooler core, a part of the turbine wheel and a part of the radiator core are within an area enclosed by a first connecting line, a second connecting line, an engine-body front-surface and a wheel rear-surface. In an upward-downward or forward-backward direction of the cylinder axis, the intercooler-core upper end is more upward than the turbine-wheel upper end, the intercooler-core front end is more frontward than the turbine-wheel front end, the intercooler-core lower end is more upward than the radiator-core upper end, and the radiator-core rear end is more frontward than both the turbine-wheel rear end and the intercooler-core rear end.

A cooling structure of an internal combustion engine includes a thermostat provided to switch circulation between a radiator passage and a bypass passage in an engine body, to thereby enable acceleration of early warming up via the bypass passage without impairing the external appearance or increasing the size of the internal combustion engine. The cooling structure also includes an in-cylinder-block fluid passage partitioned up and down in an axial direction of a cylinder axis into an in-cylinder-block upper fluid passage and an in-cylinder-block lower fluid passage by a partition wall. The bypass passage is partially composed of the in-cylinder-bock lower fluid passage.

An intake duct has a front-rear two-split structure, and includes a rear duct connected to a body frame and a front duct connected to the rear duct. The rear duct includes a body frame connection portion that is connected to the body frame and is attached with a rear stay that supports a cowl and a meter, and the front duct is directed forward from the rear duct.

A coolant bottle defines a first chamber and a second chamber fluidly coupled to the first chamber at a valve seat. The first chamber is fluidly coupled to a source of heated engine cooling fluid, while the second chamber is fluidly coupled to an engine water pump. A thermally responsive actuator is disposed within the first chamber, and has a thermally actuated sliding member having a valve seat engaging surface. The thermally actuated sliding member is movable from a first open position to a second closed position when the coolant is above a first temperature. The thermally responsive actuator is disposed within the first chamber.