Patent ID: 6227922
Filing Date: 2001-05-08
Classification: B63H,F02B,F02D,Y02T

Abstract:
A watercraft having an engine powering a water propulsion unit, the engine having a starter motor and an exhaust port leading from a combustion chamber through which port the exhaust products may be transported and an exhaust valve cooperable with the exhaust port and movable between a first position in which the closing of the exhaust port is delayed and a second position in which the closing of the exhaust port is advanced, the watercraft having a control unit powered by a power source and a drive control capable of moving the exhaust valve at least partially between the first position and the second position in an exhaust cleaning operation, the control unit activating the drive control after the starter motor is engaged and before the engine attains a first predetermined speed so as to cycle the exhaust control valve, and the control unit deactivating the drive control after the engine attains a second predetermined speed so as to disable controlled movement of the exhaust control valve.