Exhaust Control System for Motorcycle 4-Stroke Engines 880269
Recent improvements of performance in 4-stroke motorcycle engines are remarkable. However, these improvements have come at the expense of idling stability and erratic performance in the low to medium range of engine speeds.
In order to solve these problems, a variable exhaust valve system has been developed. A valve, located at the end the exhaust passage area (sometimes refered to as the “collector”), varies its opening in order to control the pressure pulsation waves in the exhaust pipe, and is regulated as a function of engine speed. This system has already been adopted on some production motorcycles since April 1987.