A handheld four-stroke engine lubricating system, comprising an oil storage chamber (1) formed by a bottom casing (32) and a lower crank case (31), a crankshaft chamber (2) formed by the lower crank case (31) and an upper crank case (33), an air valve cham...

A four-stroke internal combustion engine (20) is provided. There is provided within an engine housing (28) an oil reservoir (126) and a valve chamber (156) which independently communicate with a crank chamber (124). A strategically placed divider (116) and...

A four-stroke engine includes a piston cylinder, and a piston located in the cylinder and movable within the cylinder. The engine includes a crankcase attached to the cylinder, the piston providing a separation boundary of a combustion portion of the cylin...

The engine (20) has an engine block that has no further internal passages extending between a camshaft cavity and a crankshaft cavity (91). The engine block includes integrally formed cylinder (22) and cylinder head (24). An interconnected crankshaft (42) ...

A four-stroke internal combustion engine (20) is provided. There is provided within an engine housing (28) an oil reservoir (126) and a valve chamber (156) which independently communicate with a crank chamber (124). A strategically placed divider (116) and...

In an oil mist generation system, an oil slinger is disposed in an oil tank and is rotated by a crankshaft, the oil slinger scattering oil store in the oil tank by the rotation of the oil slinger so as to generate an oil mist. The oil mist generation syste...

In a handheld type four-cycle engine, the lubricating system includes an oil tank placed outside an engine main body, a through hole providing communication between the oil tank and a crank chamber, an oil feed pipe placed outside the engine main body and ...

With regard to a handheld type four-cycle engine including, in a side wall of a cylinder block, an intake valve, an exhaust valve and a valve operation mechanism operable in association with a crankshaft so as to open and close the above-mentioned valves a...