Abstract: An exhaust controller includes an exhaust control valve. The exhaust controller is capable of adjusting an exhaust timing of a spark ignition type, two stroke internal combustion engine depending upon the rotational speed of the engine. The exhaust control valve has a structure and operation which greatly reduces exhaust leakage past the exhaust control valve. As a result, the scavenging efficiency and the charging efficiency are improved and the compression ratio of the engine is better maintained. In operation, the exhaust control valve maintains a relatively consistent cross-section throughout the exhaust gas flow passage. As a result, exhaust pressure is decreased, resulting in an increase in the output and efficiency of the engine.

Abstract: An exhaust control apparatus for a high level engine output and engine efficiency for obtaining a stable operation from a low speed to a high operating speed in a spark-ignition two-stroke internal combustion engine with an exhaust timing that can be adjusted. A spark-ignition two-stroke internal combustion engine is equipped with an exhaust channel that opens via an exhaust port into the cylinder, and an exhaust control valve that is supported for reciprocation along the cylinder centerline direction along the exhaust port and that allows at least the portion of the exhaust port on the cylinder head side to be blocked. A valve body depression forms a hollow from the cylinder head side to the crank side in the exhaust control valve by a bottom wall, side walls, and a control wall. A housing depression is provided that allows the above-mentioned exhaust control valve to be withdrawn from the abovementioned exhaust channel.

Abstract: An exhaust controller for a spark ignition type two stroke internal combustion engine capable of adjusting an exhaust timing by an exhaust control valve, characterized by sufficiently cooling an outer peripheral wall of an exhaust passage. In a spark ignition type two stroke internal combustion engine, a cylinder head side outer peripheral portion of an upstream portion of an exhaust passage smoothly connected to an exhaust port is formed of an exhaust passage forming portion of a lid member closing an exhaust control valve. A crank case side outer peripheral portion of the exhaust passage is formed of a cylinder block. The cylinder head side outer peripheral portion of the exhaust passage is cooled by a cooling water passage near a cylinder head which is formed in the lid member and the crank case side outer peripheral portion of the exhaust passage is directly cooled by a cylinder block cooling water passage near a crank case which is formed in the cylinder block.

Abstract: A two-cycle engine having a crank shaft, a main transmission shaft and a balancer shaft in order to lower the center of gravity and to improve lead valve layout is provided with a casing structure containing an intake passage formed integrally with a crank chamber and a transmission chamber and wherein the intake passage is located in a portion of the casing above the axes of the crank shaft and the main shaft and the balancer shaft is located below such axes.

Abstract: A rotary type hydraulic damper for motorcycle suspension application is disclosed in which a shaft and a housing each containing oppositely extending vanes are arranged for relative rotational movement. The vanes cooperate to define alternately spaced expansion and compression chambers between which hydraulic fluid is passed in response to relative movement between the shaft and the housing. According to one aspect of the invention, a manifold arrangement includes the interconnection of the expansion chambers at one end of the housing and that of the compression chambers at the other end thereof, and a throttling device restricts the flow of fluid between the respective chambers to provide a damping force generator. According to another aspect of the invention the damper shaft provides structural support for the motorcycle drive sprocket, whereby strength requirements for the sprocket bearing case are reduced.

Abstract: A two-cycle engine having a cylinder, an exhaust port through the wall of the cylinder and an exhaust passage extending from the exhaust port with an exhaust timing control device located in the exhaust passage. The device includes a valve body which, in a first embodiment, is pivotally mounted in the exhaust passage and extends to the exhaust port. In a second embodiment, the valve body is fixed at one end and operates as a flexible resilient member to acheive variation in timing control. Each valve body is biased against a cam mechanism which may be rotated to actuate the valve body for controlling exhaust timing. The cam also provides a sealing mechanism between the valve body and the upper surface of the exhaust passage.

Abstract: In a vehicle in which the power of a power plant carried on a body frame is transmitted to a driving wheel through a wrapping transmission mechanism, a pivot shaft is extended laterally of a vehicle body and secured fixedly to a body frame, the pivot ends of the swing arm for journaling the driving wheel is pivoted to the pivot shaft, the hanger portion of the power plant is also pivoted to the pivot shaft, the output shaft of the power plant being provided concentrically on the pivot shaft relatively rotatably, to which output shaft is secured a drive wheel of a wrapping transmission mechanism.

Abstract: Exhaust apparatus for a vehicle engine, having a connecting line which connects a sub-chamber to an engine exhaust line and which is provided with an opening and closing valve connected to a power source responsive to the number of engine revolutions per minute, i.e. speed, and causing the valve to open and close in dependency of the number of such revolutions. The power source is connected to the shaft mounting the valve by elements inserted through the outer walls of an engine cylinder, the exhaust line and a crank case.

Abstract: An exhaust system of a two-cycle engine mounted on a motorcycle is provided with a subchamber branching off from the exhaust pipe. The subchamber is disposed by utilizing a so called dead space in the frame of the motorcycle, particularly in a position in front of the engine and between a pair of cradle pipes of a body frame on which the engine is mounted. With this arrangement, it becomes possible to layout the position of the subchamber without altering the configuration of the body frame, and there is further advantage that the subchamber is well protected by the structural members.