Abstract: A method for attenuating the low-frequency noise generated at the outlet (18) of an exhaust line (14). A signal representing the noise to be attenuated is defined; a first high-frequency acoustic wave (F1) is emitted from a first transducer (22) into an attenuation region (26) of the exhaust line (14), the first acoustic wave having a carrier frequency higher than 50 kHz; and a second high-frequency acoustic wave (F1+?fcb) is emitted by a second transducer (24) into the attenuation region (26) of the exhaust line, the second acoustic wave having the carrier frequency of the first high-frequency acoustic wave (F1) and containing a low-frequency counter-noise signal (?fcb) which is out of phase with the signal representing the noise to be attenuated.

Abstract: A tailpipe for use with a vehicle moveable in a forward direction upon a support surface and adapted to be oriented substantially perpendicular to the support surface. The tailpipe includes a windward surface facing in the forward direction and a leeward surface facing opposite the forward direction. The tailpipe also includes a tubular body defining a main exhaust gas flow passageway adapted to direct an exhaust gas flow from a proximal end to a distal end of the tubular body and a plurality of exhaust ports. The exhaust ports are disposed between the proximal end and the distal end of the tubular body and pass through the leeward surface for permitting at least a portion of the exhaust gas flow, when present in the tubular body, to exit the tubular body through the plurality of exhaust ports.

Abstract: An exhaust tip assembly conducts hot engine exhaust from a muffler through an opening in a molded plastic bumper fascia. An exhaust pipe defining a cross-sectional flow area for the exhaust flow and has an inlet end attached to the muffler and an outlet end. The exhaust pipe has a flexible coupling portion intermediate the inlet end and the outlet end. A heat shield has a cross-sectional flow area greater than the pipe, and an inlet end attached to the outlet end of the pipe. A decorative bezel is attached to the heat shield at the outlet end of the heat shield. Fasteners fasten the heat shield to the fascia with the bezel located in the opening in the rear bumper fascia. During movement of the muffler, the bezel remains in the center of the opening as the flexible coupling portion of the exhaust pipe flexes.

Abstract: A high-performance muffler assembly for exhaust system of an internal combustion engine. The muffler assembly comprises an elongated casing having an inlet port and an exit port, a first pipe disposed within the casing and having an inlet end in fluid communication with the inlet port and an outlet end selectively fluidly connected to the exit port of the casing, and a first valve mounted within the casing. The first valve is selectively movable between a closed position and an open position for regulating an exhaust gas flow through the first pipe. The muffler assembly is operable in a number of different modes of operation including a high-performance mode, an exhaust braking mode, a reverse-flow mode, etc., determined by the positions of the first valve of the muffler assembly.

Abstract: A vehicle, such as a motorcycle, can include an exhaust pipe connected to a back or rear side of an engine of the vehicle. A rear cushioning member can be provided between the engine and a rear wheel of the vehicle. The exhaust pipe can include a front portion that extends from the engine backward on one side of the rear cushioning member, with respect to a widthwise direction of the vehicle, and a transverse portion that extends, in a direction substantially transverse to a lengthwise direction of the vehicle, from the one side to another side, between the rear cushioning member and the rear wheel.

Abstract: An exhaust system for an engine includes a first muffler having a housing, a first end plate, a second end plate, an inlet pipe extending through at least one of the first end plate and the second end plate, and an outlet pipe extending through at least one of the first end plate and the second end plate. The exhaust system further includes a second muffler having a housing, a first end plate, a second end plate, an inlet pipe extending through at least one of the first end plate and the second end plate, and an outlet pipe extending through at least one of the first end plate and the second end plate. The exhaust system further includes a crossbreed pipe extending through the first end plate of the first muffler and the first end plate of the second muffler.

Abstract: A housing for a component of an exhaust system has an opening which is provided in the housing, and a pipe which is arranged in the opening and connected with the housing. The pipe projects out of the housing and is connected with a connecting pipe shortly behind the opening. The invention further relates to such a component.

Abstract: An exhaust system for a motorcycle provides enhanced steering stability and improved function for purifying exhaust gas. Front exhaust pipes connected with front cylinders of a V-type engine are joined to a front part of an exhaust chamber. Rear exhaust pipes connected with rear cylinders of the engine are joined to an upper part of the exhaust chamber. Exhaust gases discharged from both the front and rear exhaust pipes are unified within the exhaust chamber, and a catalyst is disposed in the vicinity of the unifying section. The length of the rear exhaust pipes is shorter than the length of the front exhaust pipes. High-temperature exhaust gas is introduced to the catalyst contained within the exhaust chamber via the rear exhaust pipes.

Abstract: An exhaust component includes at least one muffler that has an inlet and an outlet. One pipe body is connected to each of the inlet and the outlet. The pipe bodies each have first and second ends that define a respective overall pipe length. Each pipe body defines a sole exhaust flow path between their first and second ends. A passive valve assembly is mounted outside of the muffler and within one of the pipe bodies. The passive valve assembly is positioned at a location within a first 25% of the overall pipe length of one of the pipe bodies relative to the inlet or outlet of the muffler.

Abstract: An exhaust system for an engine that reduces muffler weight, assures a silencing effect and prevents a leak of exhaust gas. A muffler has an inner cylinder disposed in an outer cylinder, and is separated into a plurality of expansion chambers. A communicative passage for communicatively connecting the expansion chambers together is formed between the outer and inner cylinders. Edge parts of the communicative passage contact the outer cylinder and are welded thereto.

Abstract: In the vicinity of the floor of a vehicle and downstream of the muffler, a pair of cross members are provided to sandwich the first portion (i.e. the intermediate portion) of the exhaust pipe from the top and bottom. The minimum distance in the vertical direction of the cross members is smaller than the maximum height of the muffler. By doing this, when the muffler is displaced toward the rear of the vehicle, the muffler comes into contact with and is caught by the pair of cross members. The distance in the longitudinal direction of the vehicle between the part of the cross members which the muffler catches on and the part of the muffler which the cross members make contact with is set to be a smaller value than the minimum distance between the second portion of the exhaust pipe and the fuel tank.

Abstract: A mat member includes inorganic fibers, a first surface and a second surface opposite to the first surface. The first surface has a plurality of needle penetration marks and/or a plurality of needle protrusion marks. The second surface has a plurality of needle protrusion marks and/or a plurality of needle penetration marks. A plurality of needle marks are formed in the mat member by needle punching and extend from the needle penetration mark to the needle protrusion mark. An inorganic fiber bundle which includes a plurality of the inorganic fibers oriented in a closed loop configuration is formed at the needle protrusion mark.

Abstract: An exhaust diffuser is disclosed for coupling to an exhaust system of a vehicle that, when in one orientation, is designed to exhaust gasses laterally and downwardly from the exhaust diffuser.

Abstract: In an exhaust system of a motor vehicle, a tailpipe cover is disposed on the exhaust pipe and protrudes through a cutout in the vehicle rear part with a defined gap clearance. In a hot condition, where a length of the exhaust system is increased due to thermal expansion, a greater clearance arises between the edge of the cutout and the tailpipe cover than in the cold condition. The tailpipe cover is trumpet cone shaped.

Abstract: An exhaust pipe for an internal combustion engine includes an inner tube carrying a flow of exhaust gas and surrounded by an outer tube, with an insulating layer disposed between the inner tube and the outer tube. The inner tube has at least one region formed with a nub-shaped profile in contact with the flow of exhaust gas.

Abstract: A muffler assembly includes first and second muffler components that are each formed as a single piece. The first muffler component includes a first outlet pipe portion, a first bypass pipe mount portion, and a first resonator shell portion. The second muffler component includes a second output pipe portion, a second bypass pipe mount portion, and a second resonator shell portion. The first and second muffler components are positioned in an overlapping relationship such that respective portions are aligned with each other to form an outlet pipe, a bypass pipe mount, and a resonator shell. A noise attenuation valve assembly is also installed within the first and second muffler components. The bypass pipe mount is positioned at a non-perpendicular orientation relative to the outlet pipe such that a bypass pipe having a straight end mount can be received within the bypass pipe mount to bypass the noise attenuation valve assembly.

Abstract: A muffler includes a shell main that is formed in a cylinder with two openings opposite to each other being apart from each other in an axial direction of the shell main body by rolling a flat plate to have an overlapped portion overlapping an inner end portion and a shell portion, and a pair of end plates that are partially inserted in the openings of the shell main body and fixed to the shell main body. The inner end portion is formed with two cut-off portions at opening-side edges of the inner end portion, respectively, to avoid interference between the inner end portion and the end plates when the end plates are inserted into the openings of the shell main body.

Abstract: An exhaust system for a straddle-type vehicle that achieves miniaturization while meeting a demand for noise reducing characteristics. The exhaust system is connectable to an engine, and includes an exhaust pipe connectable to the engine and a silencer. The exhaust system further comprises a tail pipe inserted into the silencer 10. The silencer comprises an outer housing and an inner core accommodated in the outer housing. An air space is provided between the tail pipe and the inner core.

Abstract: The present invention relates to a sheet-metal-type part, in particular a muffler bottom having at least one through-opening for a tubular part. The sheet-metal-type part has at least one slot passing through the sheet-metal-type part in an area adjacent to the through-opening. The slot runs essentially in the circumferential direction or runs tangentially to the through-opening.

Abstract: A Swing-arm Integrated Exhaust Silencer is disclosed. The Silencer is designed to be incorporated within the conventional swingarm of a motorcycle. One version has a removable silencer cartridge that installs within the inner chamber of the motorcycle's swingarm. Another version allows the exhaust stream to be diverted from the conventional silencer and into the inner chamber of the swingarm. In either version, the swingarm has plurality of apertures formed in it to allow for exhaust gas exit. The invention includes an adapter device that splits the exhaust gas exiting the engine and redirects it into the swingarm-integrated silencer. The exhaust adapter device is somewhat flexible to allow for movement between the swingarm, the engine, and the conventional silencer's exhaust pipe.

Abstract: A customizable integrated modular exhaust system is provided having a hollow shell muffler body formed from two symmetrical stamp formed shell members that sealably attach to a tailpipe that transverses the hollow shell, and extends through each end of the hollow shell. Exhaust gases are delivered to the muffler body from an engine, by at least one inlet tube communicably attached to the muffler body and connected to the engine via a flange. The muffler body may have various internal configurations, including a disc baffle or catalytic converter configuration.

Abstract: A vehicle exhaust assembly for improved evacuation of exhaust gases from an internal combustion engine. The system comprises a modular replacement exhaust system having a novel header pipe and muffler. The present invention readily adapts to a range of vehicle applications including automobiles, motorcycles, and all terrain vehicles.

Abstract: A muffler structure in which a subassembly formed by fixing an inner cylinder and a separator is not welded to the outer cylinder in welding an overlapping portion of a sheet metal wrapped around the subassembly. A subassembly is formed by fixing an inner cylinder and a separator. An outer cylinder is formed by first wrapping a sheet metal around the subassembly and next welding an overlapping portion of the sheet metal. The subassembly is formed with a recess opposed to a welded portion of the outer cylinder.

Abstract: A straddle-type vehicle with enhanced heat exhaust efficiency in a transmission case housing a continuously variable transmission. The continuously variable transmission and an engine are arranged forward of a rear wheel 4. An air intake duct introduces outside air into the transmission case and an air exhaust duct exhausts air from the transmission case. The air exhaust duct is connected to and extends upward from a top portion of the transmission case. The air exhaust duct has an air exhaust port that is positioned above the transmission case.

Abstract: A housing for a flue gas unit is provided that includes a closed jacket and two end walls as well as an insert with inlet pipe an outlet pipe and retaining walls, wherein one of the pipes exits from the housing jacket radially. The housing jacket is cut out around the one pipe, the cutout is closed by a concave closing panel adapted to the shape of the cutout, and the closing panel has an opening for the radial pipe end.

Abstract: A fuel cell system with a muffler to reduce noise generated while supplying air to a fuel cells disclosed. One embodiment of the fuel cell system includes an air feeder to supply air; an electric generator to generate electricity through an electrochemical reaction between air and fuel; and a muffler provided in one end of the air feeder. The muffler includes a first pipe and a second pipe which are different in length from each other. The muffler has a relatively small structure, so that limitation in a mounting space can be decreased and a more compact fuel cell system can be realized. Also, even if there are considerable noise components at two or more frequencies, the mufflers corresponding to the respective frequencies are connected in series, thereby reducing the noise.

Abstract: A muffler outlet part for a muffler to be used in exhaust systems of motorcycles has at least one main body disposed transversely to an outflow direction of exhaust gas and having a center axis, the main body having a centrical first outlet opening disposed concentrically relative to the center axis for the outflow of exhaust gas from an outlet chamber of the muffler, and at least one second outlet opening disposed eccentrically relative to the center axis for the outflow of exhaust gas from an expansion chamber of the muffler, said expansion chamber enclosing the outlet chamber. It further has at least one closing member that is swivel-mounted about the center axis for an at least partial closing of the at least one second outlet opening, and at least one adjustment element for swiveling of the closing member via an adjustment means, which cooperates in a torque-transmitting manner with the at least one adjustment element.

Abstract: An exhaust member having two or more exhaust ports separated by a partition wall extending between an inner wall of a tubular portion, wherein said partition wall has the minimum thickness A in a range within ½ of the length of said partition wall from its longitudinal middle point as a center, when viewed in an arbitrary transverse cross section of said tubular portion (including an opening end surface) having said partition wall; wherein said partition wall becomes gradually wider outside said range; and wherein each cuter surface of said partition wall exists in a region sandwiched by (a) an inner line comprising a parallel line H1, H2 separate from the longitudinal centerline of said partition wall by a distance of A/2, and an arc R1, R2 tangentially connected to said parallel line H1, H2 and said inner wall and having a radius r1, r2, wherein both r1 and r2 are ?×A or more, meeting r1+r2=1.

Abstract: A muffler for a small engine includes a first expansion chamber 12 for exhaust gas having an exhaust gas inlet 11 being connected to an exhaust gas outlet of the engine, a second expansion chamber 15 being partitioned from the first expansion chamber 12 by a partition plate 14 and being communicated with the first expansion chamber 12 through a first communicating hole 13 on the partition plate 14, and a third expansion chamber 18 being partitioned from the second expansion chamber 15 by the partition plate 14 and being communicated with the second expansion chamber 15 through a second communicating hole 16 on the partition plate 14 and having an exhaust gas outlet 17. A first heat resistant mesh catalyst 19 is disposed on the exhaust gas inlet 11. A first exhaust gas purifier 20 composed of a heat resistant knit fabric 20a coated with a catalyst for purifying the exhaust gas is disposed on the communicating hole 13 on the partition plate 14.

Abstract: An exhaust system for a motorcycle engine including a header having an upstream end adjacent a combustion chamber of the engine and having a downstream end opposite the upstream end. The exhaust system includes a catalytic converter positioned downstream of the combustion chamber and configured to improve the emissions quality of exhaust gases discharged from the combustion chamber. The exhaust system further includes a perforated section at least partially defining an exhaust passageway, the perforated section disposed adjacent the downstream end of the header. A resonator chamber is in fluid communication with the perforated section. The resonator chamber is configured to allow expansion of the exhaust gases in the exhaust passageway through the perforated section.

Abstract: A configurable motorcycle exhaust assembly, including an elongated hollow body; an inlet end cap fixedly connected to an inlet end of the elongated hollow body; an exhaust end mount fixedly connected to an exit end of the elongated hollow body; and an exhaust end cap removably attached to the exhaust end mount.

Abstract: The invention concerns an exhaust gas cooler employed with a tailpipe of a vehicle exhaust system and a method of cooling exhaust gasses before being emitted from the exhaust system into the atmosphere. The exhaust gas cooler may include a cooler housing having a substantially cylindrical shape with an open forward edge, an open rearward edge, and an internal diameter that is larger than the external diameter of the tailpipe, and a cooler support attached to and supporting the cooler housing such that the rearward edge of the tailpipe is located within the cooler housing between the forward and rearward edges of the cooler housing.

Abstract: In a vehicle exhaust system support structure, an upstream side exhaust pipe connected to an engine is guided to an inlet of a muffler supported on a vehicle body, and a downstream side exhaust pipe coupled to an outlet of the muffler is disposed in the interior of a rear bumper. The upstream side exhaust pipe and the inlet of the muffler are coupled to each other via a flexible tube, thus floatingly supporting the upstream side exhaust pipe in the muffler. The downstream portion of the upstream side exhaust pipe passes through the interior of the flexible tube, and is inserted into the inlet of the muffler.

Abstract: The present invention is a two part motorcycle exhaust guard that attaches to the front and rear sections of a motorcycle's exhaust can. The front guard is made of a set of cantilevered steel, metal or alloy plates that house an interchangeable polymer or composite wear pad on an outer surface thereof. The front guard is itself attached to the exhaust but is reinforced from forceful removal through the use of a retention strap. The rear guard is also adapted to house a wear pad and mounts on the rear of the exhaust can.

Abstract: A passive, exhaust pressure actuated valve assembly for placement inside a tubular exhaust conduit is pivotally mounted to an off-center axle for rotation between fully closed and fully opened positions. A bias element forces the valve flap toward the fully closed position. The valve flap is shaped in a manner enabling use of the interior surface of the exhaust conduit to define stops at the full closed and full opened positions. The valve flap shape, in conjunction with the bias element arrangement, enables the flap to lie substantially parallel to a longitudinal axis of the conduit in the fully opened position, which provides for minimum back pressure in the conduit.

Abstract: An exhaust device includes an exhaust pipe connected at its upstream end to a cylinder head of the engine and an exhaust muffler connected to the downstream end of the exhaust pipe for suppressing the generation of noise from a heat insulating cover that covers a part of the exhaust pipe. A heat insulating cover covers a portion of the exhaust pipe near the engine and a stay is fixed to the heat insulating cover. The stay includes a supporting plate portion curved so as to partially surround the outer circumference of the exhaust pipe. A first vibration isolating member is provided that is sandwiched between the outer circumference of the exhaust pipe and the supporting plate portion, a band member is tightened to mount the supporting plate portion to the exhaust pipe, and a second vibration isolating member is sandwiched between the supporting plate portion and the band member.

Abstract: A passive secondary air muffler for a small internal combustion engine. The secondary air muffler may include a venturi device and a catalytic converter. The venturi device may be in the form of a stamped sheet metal insert which, along with the outer muffler housing or shell, forms a secondary or auxiliary air intake device. The venturi device may also be formed from baffles separating an inlet chamber from an outlet chamber of the muffler. The secondary air intake device provides auxiliary or secondary air to the exhaust gas stream exiting the engine upstream of the catalytic converter to improve the efficiency of the catalytic converter. In an exemplary embodiment, the venturi device has a hemispherical cross-sectional shape or a circular cross-sectional shape taken along a plane substantially perpendicular to the direction of flow of the exhaust gas stream.

Abstract: An exhaust system for a motorcycle includes a plurality of exhaust pipes connected respectively to exhaust ports of cylinders of a multi-cylinder engine; a manifold portion connected to the exhaust pipes; and a muffler connected to a downstream side of the manifold portion, the manifold portion being disposed below the engine, wherein the manifold portion is disposed sideways of an oil pan disposed below the engine so as to overlap the oil pan when seen in a side view of the motorcycle, and the exhaust pipes are connected to the manifold portion from a front side of the motorcycle.

Abstract: An exhaust throttle valve protected from disturbance due to stones scattered during operation of a vehicle. Front side exhaust pipes and rear side exhaust pipes are connected to a catalyst chamber disposed below a crankcase. The exhaust chamber and an exhaust chamber to the rear thereof are connected to each other via a rear exhaust pipe. The diameter of the rear exhaust pipe is smaller than the lateral width of each of the catalyst chamber and the exhaust chamber, so that a recessed space is externally formed so as to recede inside of the vehicle. An exhaust throttle valve is received in the space. The exhaust throttle valve is partially exposed to the outside of the rear exhaust pipe and a throttle valve is received in the rear exhaust pipe to throttle-control the passage-sectional area of the rear exhaust pipe according to the rotation of the engine.

Abstract: A muffler for a motorcycle, the muffler including an outer tube and an inner tube disposed substantially within the outer tube. The inner tube includes a first end adapted to receive the exhaust gases from the engine, a second end opposite the first end adapted to release the exhaust gases to the environment, and first and second apertures positioned between the ends. The muffler also includes a mesh tube disposed between the outer tube and the inner tube. The mesh tube defines a chamber between the inner tube and the mesh tube such that the exhaust gases exit the inner tube through the first aperture into the chamber, and exit the chamber into the inner tube through the second aperture. The muffler also includes a noise attenuating material disposed between the mesh tube and the outer tube.

Abstract: In an exhaust system, exhaust manifolds are connected to two banks provided in a V-type engine of a vehicle, respectively, to which front pipes each having a catalytic converter are connected to the exhaust manifolds, respectively. A muffler is provided at an exhaust downstream side of the exhaust pipes, and a rear pipe is further connected to the exhaust downstream side of the muffler. The front pipe has its rear end portion located near a through hole formed in the rear pipe. A path length of one of the front pipes from the bank to the muffler is made shorter than that of the other front pipe.

Abstract: A vehicle exhaust system structure is obtained which can protect well a bend portion of an exhaust pipe. A vehicle exhaust system structure 10 is intended to discharge exhaust gases of a front-engine front-drive vehicle with a transverse engine from a rear part of a vehicle body and is applied to an exhaust system 11 which is configured such that a first catalytic converter 12, a second catalytic converter 14, an exhaust system heat exchanger 15 and a muffler 16 are disposed sequentially in that order from an upstream side in an exhaust gas flow direction. In the exhaust system 11, a heat exchanger to muffler exhaust pipe 26 which connects the exhaust system heat exchanger 15 to the muffler 16 has an inclined portion 26A, and a portion of the exhaust system 11 which lies further rearwards than the exhaust system heat exchanger 15 is suspended from the vehicle body by a suspension unit 80.

Abstract: A variable geometry muffler for an exhaust system of an internal combustion engine; the muffler displays: a tubular body, which displays an inlet opening, an outlet opening and a labyrinth which determines a path for the exhaust gases from the inlet opening to the outlet opening; and a bypass valve, which is arranged within the tubular body to modify the geometry of the labyrinth according to the exhaust gas pressure; the bypass valve displays a lid, which is coupled to a bypass opening and is mobile from a closed position of the bypass opening to an opening position of the bypass opening by effect of the exhaust gas pressure and against the bias of an elastic body which tends to maintain the lid in the closed position; the elastic body consists of an elastic foil, which is folded as a “U” and displays a mobile end which supports the lid and a fixed end which is opposite to the mobile end and which is integral with a fixed part of the muffler.

Abstract: In order to provide an exhaust system for a combustion engine with an outer casing in which hot exhaust gas is introduced through an exhaust inlet and discharged from an exhaust outlet wherein the exhaust outlet is of a tubular, more preferably having a circular or oval cross section design which, in a simple way, preferably effectively lowers the exhaust gas temperature in the exhaust outlet it is proposed that arranged in the area of the tubular exhaust outlet is an exhaust swirling device having at least one guide blade through which the exhaust gas is deflected in the exhaust outlet.

Abstract: To provide a muffler device capable of improving the discharge of exhaust gas, while discharging the exhaust gas in any desired direction. The muffler device is connected to a rear end portion of an exhaust pipe extending from an internal combustion engine of a vehicle. An exhaust outlet opening is provided that opens outwardly and laterally of the vehicle and is disposed at a rear portion of a muffler main body. The muffler main body is provided with a muffler side cover and an end cap as muffler covers. The muffler side cover includes a slit. The slit serves as an air intake guide shaped portion for guiding ambient air so that the ambient air crosses the exhaust outlet.

Abstract: An exhauster for a motorcycle with a reduced number of components and reduced cost in a structure containing a variable passage area valve. An exhaust chamber has a box-shaped chamber main body, a plurality of expansion chambers a through c formed by sectioning the interior of the chamber main body with partitioning walls, and communication passages for connecting the expansion chambers a through c with one another. A variable passage area valve that controls passage area is contained in the communication passage.

Abstract: An exhaust diffuser is disclosed for coupling to an exhaust system of a vehicle that, when in one orientation, is designed to exhaust gasses laterally and downwardly from the exhaust diffuser.

Abstract: The shell main body for a muffler includes an inner shell in a cylindrical shape with a cross-section of an imperfect circle defined by small arc portions alternating with large arc portions; and an outer shell wrapping the inner shell and formed in a cylindrical shape similar to the inner shell. An end portion of the inner shell and an end portion of the outer shell are overlapped in a circumstantial direction of the shell main body to form a shell overlap portion that is capable of discharging vapor in a gap of the large arc portions formed between the inner shell and the outer shell into one of an outside and an inside of the shell main body. This shell overlapping portion is located in one of the small arc portions.

Abstract: To provide a motorcycle exhaust system, which is less susceptible to the elevated temperature of the exhaust gases and vibrations induced by the motorcycle combustion engine (E) and in which the sectional area of the exhaust passage can be properly adjusted independence on the operating condition of the motorcycle combustion engine (E), the motorcycle exhaust system includes a motorcycle combustion engine (E) mounted at a location generally intermediate between front and rear wheels (3 and 9), an exhaust passage fluidly connected at one end with an exhaust port of the motorcycle combustion engine (E), a silencer (17) fluidly connected with the opposite end of the exhaust passage and supported by the motorcycle frame structure (FR) at a location generally above the rear wheel (9); and an exhaust control valve (24) disposed in an inlet of the silencer (17) for variably adjusting the sectional area of the exhaust passage.

Abstract: To provide an exhaust device for enhancing the appearance quality, secure the degree of freedom in designing and enhance the cooling performance. An exhaust device in which a second exhaust muffler at a rear portion of an exhaust system extends rearwardly from an engine is disposed in a rear portion of a rear cowl wherein a rear end surface of the second exhaust muffler is covered with a resin-made muffler rear cover.