Abstract: An exhaust control device for an engine performs exhaust control of an exhaust system composed of exhaust pipes connected to a plurality of cylinders respectively and gathering to a collecting pipe. The exhaust control device includes at least two kinds of exhaust valves that perform the exhaust control at different parts in the exhaust system; and a single actuator that drives the exhaust valves to open and close.

Abstract: An exhaust system for a motorcycle having an engine mounted on a front half of a body frame of the motorcycle includes a plurality of first exhaust pipes extending from exhaust ports of the engine, a collecting section at which the first exhaust pipes are collected, a second exhaust pipe including a substantially straight portion connected to a downstream side of the collecting section and disposed under a crankcase of the engine, an expansion chamber connected to a downstream side of the second exhaust pipe and located under a rear wheel suspension arranged behind the engine, an exhaust outlet disposed on a most downstream portion of the expansion chamber, and an exhaust throttle valve and an exhaust gas sensor disposed on the straight portion of the second exhaust pipe.

Abstract: An exhaust system for a motorcycle having an engine mounted on a front half of a body frame of the motorcycle includes a plurality of first exhaust pipes extending from exhaust ports of the engine, a collecting section at which the first exhaust pipes are collected, a second exhaust pipe including a substantially straight portion connected to a downstream side of the collecting section and disposed under a crankcase of the engine, an expansion chamber connected to a downstream side of the second exhaust pipe and located under a rear wheel suspension arranged behind the engine, an exhaust outlet disposed on a most downstream portion of the expansion chamber, and an exhaust throttle valve and an exhaust gas sensor disposed on the straight portion of the second exhaust pipe.