Abstract: A connecting indentation or protrusion section is formed on one end section of an arm member of a lever, and by pressing one end section of a shaft pipe member to a indentation or protusion of the arm member the two members are engaged. The two members are integrally formed by fillet welding to from a clutch control lever for a motorcycle.

Abstract: A connecting indentation or protrusion section is formed on one end section of an arm member of a lever, and by pressing one end section of a shaft pipe member to a indentation or protusion of the arm member the two members are engaged. The two members are integrally formed by fillet welding to from a clutch control lever for a motorcycle.

Abstract: To provide a multi-cylinder engine for a motorcycle, in which at least one of a plurality of engine valves provided in a cylinder head for each of combustion chambers corresponding to a plurality of cylinder bores arranged in the width direction of a body frame can be rested in a specific operational region by a hydraulic valve resting mechanism. A hydraulic control valve is provided for controlling the hydraulic pressure of working oil supplied to the valve resting mechanism and is mounted on the cylinder head. The length of the multi-cylinder engine along the width direction of the body frame is made as short as possible although the hydraulic control valve is mounted in the cylinder head. A hydraulic control valve is mounted on a side surface of a cylinder head to which a plurality of intake ports are opened along the longitudinal direction of a body frame.

Abstract: A secondary air supply passage joins a reed valve chamber provided on a cylinder head cover and an exhaust gas port. The secondary air supply passage includes three aligned passages formed in a cylinder head, a cam holder and a cylinder head cover. The secondary air supply passage is formed perpendicular to a cylinder head gasket. One end of the secondary air supply passage opens to a secondary exhaust gas air induction part, formed integrally with a core of the exhaust port, during casting of the cylinder head.

Abstract: A starter motor and balancers are disposed reasonably so as not to interfere with each other by effectively utilizing spaces in an engine. Cylinders are set so as to be tilted forward on casings supporting a crankshaft in a transverse position, a rear balancer and a starter motor are disposed in a space behind the cylinders, and a front balancer is disposed on an opposite side of the rear balancer with respect to the crankshaft. The rear balancer and the front balancer are disposed on the right side of a plane including the center of gravity of the engine and perpendicular to the crankshaft, and the starter motor is disposed on the left side of the plane. Weight portions included in the rear balancer and the front balancer are disposed close to the plane to prevent coupling vibrations.

Abstract: A motorcycle engine having an exhaust passage air introduction system. Each cylinder includes two exhaust passages which are joined at a point displaced from the engine. Air is introduced into one of the exhaust passages of the two so as to more fully combust the unburned gasses within the exhaust passage and then to more fully combust the unburned exhaust in the joined passage. The timing of the valves associated with each exhaust passage is such that the valve associated with the passage having the air inlet has advance timing. A chain tensioner for the timing chain includes a tensioner cylinder hydraulically actuated by the engine oil. A gasket having an orifice therein is positioned between components in the oil passageway extending to the tensioner cylinder. The oil cooling system of the engine includes an oil filter and an oil cooler which are displaced from one another and mounted to a common base which is in turn mounted to the engine.

Abstract: A lubricating system for an engine comprises an oil pan for storing a lubricating oil therein, an oil cooler for cooling the lubricating oil, and an oil pump including first and second pump rotors contained in a casing. The oil pump is provided with a suction port commonly used for both the pump rotors, a first discharge port exclusively used for the first pump rotor and a second discharge port exclusively used for the second pump rotor. The suction port is in communication with the subsurface of the oil in the oil pan, the first discharge port communicating with an inlet port of the oil cooler, and said second discharge port communicating with the to-be-lubricated portions of an engine.