There is provided a saddle-ridden type vehicle. An air intake piping is connected between an air cleaner and a supercharger. An air outlet piping is connected between the supercharger and an intercooler. An air bypass passage is provided between the air outlet piping and the air intake piping to allow compressed air to escape toward an upstream side of the supercharger without flowing in the supercharger. An air bypass valve is configured to open and close the air bypass passage. The supercharger is disposed in front of the engine. The air cleaner is disposed above the engine. The air intake piping extends in an upper-lower direction in a region ranging from the above of the engine to a front of the engine at one side in a vehicle width direction. The air bypass valve is disposed at the rear of the air intake piping.

A four-cycle multi-cylinder engine includes a crankcase, a cylinder block, a crankshaft, and a gear-shift input shaft. The crankcase is vertically divided into an upper case and a lower case. The cylinder block is integrated with the crankcase. The crankshaft and the gear-shift input shaft are journaled to a contact surface of the crankcase. The cylinder block is inclined rearward such that an extended line intersects with a cylinder axis line of the cylinder block at an acute angle in an engine side view. The extended line connects respective central axes of the crankshaft and the gear-shift input shaft.

A device and method for cooling an air cooled motorcycle engine. A fan and a cover acting as a duct directs engine heat forward away from a rider when the motorcycle engine is hot and the motorcycle is stopped. When the motorcycle is in motion the fan is switched off and the passing air takes a reversed path and flows rearward over the engine fins cooling the engine.

A radiator structure for a two-wheeled vehicle includes a radiator main body having a front surface positioned to face a running direction, and a radiator grill having a mesh part which is positioned in front of the radiator main body to cover the radiator main body. The radiator grill is positioned behind a front wheel of the two-wheeled vehicle and has a mud guard portion which fills in the mesh part in a region SWF onto which the front wheel is projected as viewed from the front.

A cooling system includes a rear radiator that is mounted in a vehicle and circulates cooling water to release heat of the cooling water. A fan that generates cooling air to cool the rear radiator, and a shroud 50 is provided between the fan and the rear radiator and guides the cooling air. The shroud has a double structure having an internal space; the internal space enables the cooling water to pass through the internal space when the cooling water circulates.

A cover structure of an internal combustion engine of a motorcycle includes an engine that is mounted on a motorcycle and includes a cooling device for cooling the engine. The cover structure includes a sprocket cover portion that covers from the width direction of the vehicle. The cover structure also includes a pipe cover portion that covers from the width direction of vehicle a discharge side hose and an intake side hose of the cooling device. The cover structure further includes a side surface cover that includes a joining portion which is vertically arranged from the sprocket cover portion towards the pipe cover portion so as to be in parallel with the discharge side hose. The intake side hose is arranged side by side in the width direction of the vehicle and integrally joins the sprocket cover portion with the pipe cover portion.

The invention provides a heat exchanger for a cooling system of a motor vehicle, in particular a motorcycle. The heat exchanger includes a housing, a supply connection via which a fluid can be supplied to the heat exchanger, a return connection via which the cooled fluid can be discharged from the heat exchanger, and a heat exchange region in which the fluid interacts with a medium in order to be cooled. The fluid dispenses thermal energy to the medium. The supply connection and the return connection are arranged on a common connection side of the housing. The heat exchange region includes multiple heat exchanger tubes through which the fluid flows from the connection side to a side opposite the connection side. A singular discharge tube runs from the opposite side to the return connection. The invention further provides a cooling system and an assembly.

A drainage structure for cooling water, includes: an engine cover attached to a crankcase; and a water pump attached to the engine cover. The water pump is provided with a seal member configured to seal a pump chamber, and is formed with a drain hole for draining cooling water leaking from the seal member. The engine cover is formed with a drain passage for guiding cooling water from the drain hole to a lower surface of the engine cover, and a covering portion that extends from the lower surface of the engine cover and that covers a space below an outlet of the drain passage. The covering portion includes a side wall that covers the 10 space below the outlet from an outside in a vehicle width direction and a bottom wall that covers the space below the outlet from below.

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 saddle-ride type vehicle including: a rear wheel; a vehicle body frame including a pivot shaft extending in a vehicle width direction; a swing arm connecting the pivot shaft and the rear wheel; and a housing structure having a housing space of fluid inside the housing structure. The housing structure is disposed between the pivot shaft and the rear wheel and at a position overlapping the swing arm in a side view of the saddle-ride type vehicle.