Abstract: A piston cooling device includes a main body which includes a communication path communicating with an oil passage provided in the internal combustion engine, a nozzle pipe portion which includes an oil injection port for injecting an oil passing through the communication path, toward the piston, and a filter which is provided at an upstream side of the nozzle pipe portion in an oil flow path to filter the oil. The main body includes a cylindrical portion inserted into the oil passage. The filter has a bottomed cylindrical shape in which a filter side surface stands from a filter bottom surface, and is held inside the cylindrical portion. Filter holes are formed in the filter bottom surface and the filter side surface. The filter is disposed such that the filter bottom surface protrudes further upstream side in the oil flow path than a tip end of the cylindrical portion.

Abstract: A piston cooling device includes a main body which includes a communication path communicating with an oil passage provided in the internal combustion engine, a nozzle pipe portion which includes an oil injection port for injecting an oil passing through the communication path, toward the piston, and a filter which is provided at an upstream side of the nozzle pipe portion in an oil flow path to filter the oil. The main body includes a cylindrical portion inserted into the oil passage. The filter has a bottomed cylindrical shape in which a filter side surface stands from a filter bottom surface, and is held inside the cylindrical portion. Filter holes are formed in the filter bottom surface and the filter side surface. The filter is disposed such that the filter bottom surface protrudes further upstream side in the oil flow path than a tip end of the cylindrical portion.

Abstract: A secondary-air supply structure for a saddle-ride type vehicle includes a cylinder block and a cylinder head which extend upward from a crankcase, and right and left secondary-air supply pipes which are connected to the right and left of an exhaust outlet portion of the cylinder head and through which secondary air is supplied to an exhaust port. The right and left secondary-air supply pipes extend from the front surface of the cylinder head to the right and left of the cylinder head, respectively, and include bent-back pipe sections extending along the right and left surfaces of the cylinder head and bent back toward the front side.

Abstract: A secondary-air supply structure for a saddle-ride type vehicle includes a cylinder block and a cylinder head which extend upward from a crankcase, and right and left secondary-air supply pipes which are connected to the right and left of an exhaust outlet portion of the cylinder head and through which secondary air is supplied to an exhaust port. The right and left secondary-air supply pipes extend from the front surface of the cylinder head to the right and left of the cylinder head, respectively, and include bent-back pipe sections extending along the right and left surfaces of the cylinder head and bent back toward the front side.

Abstract: A chain tensioner includes a base frame secured to each of front and rear banks, a slider plate shiftable in the extending direction of the base frame, and a tensioner provided to straddle between the base frame and the slider plate. The slider plate is biased to elastically deform and arcuately bend the tensioner, which applies a tensile force to each of cam chains transmitting the rotation of a crankshaft. In the chain tensioner, upper securing portions are provided in an upper portion of the base frame so as to be secured to each of the front and rear banks in the bending direction of the tensioner. A lower end of the base frame extends to a position facing the inside of the crankcase to provide a lower securing portion which is secured to each of the front and rear banks perpendicularly to the bending direction of the tensioner.

Abstract: An ignition device attachment structure for an internal combustion engine includes an ignition plug tube inserted between a cylinder head cover and an ignition device insertion hole formed in a cylinder head of the internal combustion engine. The ignition plug tube bulges from an upper end of the ignition plug tube to an intermediate portion of the ignition plug tube on a lateral surface of the ignition plug tube.

Abstract: A secondary air supplying system of an internal combustion engine includes secondary air valve chambers to control the supply of secondary air. The secondary air valve chambers are formed in a cylinder-head cover that covers a cylinder head from above. In such a secondary air supplying system, a cam shaft and a rocker-arm shaft are offset from a cylinder axis L and are disposed at respective sides of the cylinder axis L from each other. In addition, the secondary air valve chambers are formed at the rocker-arm-shaft side of the cylinder axis L. With this configuration, it is possible for the secondary air valve chambers formed in the cylinder-head cover to be disposed as close as possible to a cylinder head, and the internal combustion engine can be made more compact in size.

Abstract: An ignition device attachment structure for an internal combustion engine includes an ignition plug tube inserted between a cylinder head cover and an ignition device insertion hole formed in a cylinder head of the internal combustion engine. The ignition plug tube bulges from an upper end of the ignition plug tube to an intermediate portion of the ignition plug tube on a lateral surface of the ignition plug tube.

Abstract: A chain tensioner includes a base frame secured to each of front and rear banks, a slider plate shiftable in the extending direction of the base frame, and a tensioner provided to straddle between the base frame and the slider plate. The slider plate is biased to elastically deform and arcuately bend the tensioner, which applies a tensile force to each of cam chains transmitting the rotation of a crankshaft. In the chain tensioner, upper securing portions are provided in an upper portion of the base frame so as to be secured to each of the front and rear banks in the bending direction of the tensioner. A lower end of the base frame extends to a position facing the inside of the crankcase to provide a lower securing portion which is secured to each of the front and rear banks perpendicularly to the bending direction of the tensioner.

Abstract: A secondary air supplying system of an internal combustion engine includes secondary air valve chambers to control the supply of secondary air. The secondary air valve chambers are formed in a cylinder-head cover that covers a cylinder head from above. In such a secondary air supplying system, a cam shaft and a rocker-arm shaft are offset fi-om a cylinder axis L and are disposed at respective sides of the cylinder axis L from each other In addition, the secondary air valve chambers are formed at the rocker-arm-shaft side of the cylinder axis L. With this configuration, it is possible for the secondary air valve chambers formed in the cylinder-head cover to be disposed as close as possible to a cylinder head, and the internal combustion engine can be made more compact in size.