Abstract: A cylindrical shell main body constituting a muffler main body is formed of two layers of an inner shell and an outer shell and has a cylindrical shape with a cross section that is not a perfect circle but is defined by alternated small arc portions and large arc portions similarly to an oval, or the like. The outer shell of the shell main body has, in each of their small arc portions, four radially projecting beads continuously extending in a circumferential direction along the small arc portions and being a predetermined distance apart from one another in an axial direction, thereby allowing an upper and lower gaps between the inner shell and the outer shell in the respective large arc portions of the shell main body to communicate with each other through passages formed by the beads.

Abstract: An acoustic filter is provided with a single flow chamber for exposure of a flexible rubber layer to liquid undergoing flow through the flow chamber with noise producing acoustic energy therein. The flexible rubber layer is supported on a cylindrical drum with slanted holes therein through which the exposure to the liquid in the flow chamber is effected. An axially sectioned drum with dimensionally different diameters, radial thicknesses and slanted holes therein is positioned over the rubber layer within an outer casing to establish a plurality of gas-filled cavities of different axial lengths and separated from each other along the axial length of the liquid flow chamber which is connected at its opposite axial ends by pipe sections to a piping system from which the liquid within the flow chamber is derived.

Abstract: A muffler device with catalysts for improving purifying exhaust gas of nitrogen oxides within a motorcycle exhaust pipe comprises a muffler divided into three chambers, a first chamber, a second chamber, and a third chamber; a front exhaust pipe; a front reduction catalyst; a rear exhaust pipe provided with a secondary air inlet behind the reduction catalyst for introducing secondary air therein. Thereby, the exhaust gas from an engine with air-to-fuel ratio less than or equal to 14.7 will firstly pass the reduction catalyst to have its nitrogen oxides (NOX) effectively inverted into nitrogen (N2) and oxygen (O2), and then secondary air will be added to the exhaust gas so as to increase its air-to-fuel ratio to larger than 14.7, and finally the exhaust gas will pass the oxidation catalyst to have its carbon monoxide (CO) and hydrocarbons (HC) effectively inverted into carbon dioxide (CO2) and water (H2O).

Abstract: A clamping member (2) for clamping a periphery of a rear-end open portion of an exhaust pipe (3) is accommodated in a front-end open portion (11) of a tail pipe (1). The clamping member (2) has a pair of plate parts (21, 22) disposed at right and left positions of the front-end open portion (11) and a bolt (4) for connecting the plate parts (21, 22) to each other by reducing an interval between the opposed plate parts enough to sandwich a periphery of the rear-end open portion (31) between the plate parts. A concave surface (21a, 22a) whose configuration conforms to that of a periphery of the rear-end open portion (31) inserted between the plate parts (21, 22) is formed on each of the plate parts (21, 22).

Abstract: Sound and power are an important part of the motorcycling experience. From the early days people have been attempting to get it “right” and have tried numerous ways to achieve the best of both worlds. Generally one had to be sacrificed to some degree to get the other. Tuning the exhaust rather than tuning the carburetor or increasing cubic inches is a less expensive and more efficient way to get both the sound and midrange power that motorcyclists are looking for. With the exhaust enhancement device of the present invention, exhaust pipes can be tuned for sound and increased midrange power very simply and easily by installing them in the exit end of an aftermarket straight type pipe using various combinations to achieve a desired sound and not sacrifice power.

Abstract: A silencer that comprises a casing, one or more pipes or passages leading a flow of gas to the casing and a device for leading gas from the casing. The silencer further has at least one internal chamber, one or more flow inlets to the chamber and one or more flow outlets from the chamber, and one or more flow distributing devices connected to the flow inlet(s) and/or to the flow outlet(s). The flow distributing device comprises one or more walls or profiles extending on a geometrical surface that defines a boundary between an inner volume of the flow distributing device and the chamber. The silencer further has one or more apertures for a flow of gas through the apertures and for leading gas either out of the inner volume into the chamber, or into the inner volume from the chamber. The apertures have a smallest cross-sectional transverse dimension s and a length L, the dimension s being at the maximum 0.2 times the smallest cross-sectional dimension D of the inlet or outlet.

Abstract: A self-powered, heat-activated LED exhaust tip assembly (10) that is comprised of three major elements: a cylindrical enclosure (12), a heat conducting sub-assembly (80) and an electronics circuit (130). The sub-assembly (80) consists of an external heat conducting plate (82), and an enclosure-internal heat conductive horizontal structure (110) that is attached to the plate (82) through a heat conductive vertical rod (98). When heated vehicle exhaust gases pass through the enclosure (12), the gases heat the structure (110) and the heat is then transferred to the plate (92) via the rod (98). The heat from the plate (82) is transferred to a peltier device (132) that interfaces with the plate (82). The heated peltier device (132) produces a first d-c voltage (11) that is applied to a DC to DC converter (134), where a second d-c voltage (13) is produced.

Abstract: Exhaust system assemblies employ wire bushings for thermal compensation to minimize noise due to “stick-slip” while the system cools. In a preferred embodiment, the wire bushings are formed of at least one strand of wire coiled about male end portions of pipe sections used in the system, each of which male end portions are inserted into a female end portion and held therein by an interference fit. The strand of wire is spot welded at spaced locations to the male end portions to provide bearing surfaces between the spot welds that move slightly as the exhaust system heats and cools to relieve thermal stress in small, substantially inaudible increments.

Abstract: A rear covering part fastened to a tail pipe orifice for a motor vehicle exhaust system. The rear covering part includes a completely bordered passage opening through which the tail pipe orifice penetrates. The rear covering part avoids damage to the exhaust system in the event of an accident-caused deformation. The passage cross-section of the tail pipe orifice (7, 7?), over its entire length (LG), is larger than the exterior cross-section (W3) of the tail pipe (3) of the exhaust system.

Abstract: An exhaust tip for attachment to a tailpipe that includes a thermoset heat shield at least partially surrounding and fastened to the tailpipe, and a thermoplastic decorative cover at least partially surrounding and fastened to the thermoset heat shield. The thermoset heat shield insulates the thermoplastic decorative cover from thermal effects of the tailpipe and spaces the thermoplastic decorative cover a predetermined distance away from the tailpipe.

Abstract: A mountable discharge pipe for an end muffler has devices for fastening the discharge pipe to an end muffler housing. A hook provided on the discharge pipe can be suspended at the end muffler housing, and a holding lug provided with an opening is arranged at the discharge pipe. The holding lug can be fastened by way of a nut-bolt connection on the end muffler housing. As a result, an easily mountable fastening of a discharge pipe on an end muffler is achieved.

Abstract: An exhaust processor has an exhaust tube and a cover mounted for rotation at least partially around the exhaust tube to adjust the tuning frequency of the exhaust processor. A method of operating the exhaust processor is also disclosed.

Abstract: In an exhaust housing part of a motor vehicle, particularly for an exhaust muffler or an exhaust gas catalyst of an automobile, with a sheet blank as a semi-finished part which, after a stamping process in a tool, forms an upper half shell or a lower half shell of a half-shell muffler or catalyst; or after a wrapping process in a tool, forms a wrapped exhaust gas funnel or cylinder, or an exhaust gas pipe connection; it is proposed to prefabricate the sheet blank as an integral, profiled sheet metal part of differing thickness, with at least one strip section of smaller thickness, and at least one strip section of greater thickness which locally reinforces the finished exhaust housing part (half shell, funnel, cylinder or pipe connection) at least in one wall region.

Abstract: An improved exhaust system for an internal combustion engine generally comprises two expanding megaphones, separated by a dual core annular flow silencing section. The two or split megaphone design facilitates broadening of the time of the negative pressure wave to provide a desirable broad range power output while substantially reducing obnoxious sound output.

Abstract: An exhaust manifold 14 extending downwardly is connected to a rear side of a transversely disposed engine E. A primary exhaust pipe portion 16 is connected to the exhaust manifold 14 via a spherical joint 18 provided close to the engine E. Furthermore, a secondary exhaust pipe portion 17 is connected to the primary exhaust pipe portion 16. In the primary exhaust pipe portion 17, a flexible tube 19 is disposed at a position upstream of a support portion to the vehicle body.

Abstract: Sound and power are an important part of the motorcycling experience. From the early days people have been attempting to get it “right” and have tried numerous ways to achieve the best of both worlds. Generally one had to be sacrificed to some degree to get the other. Tuning the exhaust rather than tuning the carburetor or increasing cubic inches is a less expensive and more efficient way to get both the sound and midrange power that motorcyclists are looking for. With the Exhaust Enhancement exhaust pipes can be tuned for sound and increased midrange power very simply and easily by installing them in the exit end of an aftermarket straight type pipe using various combinations to achieve a desired sound and not sacrifice power.

Abstract: The invention concerns an internal combustion engine exhaust line comprising an active noise reduction system with variable choke device, continuously regulated based on the instantaneous discharge rate pulses of exhaust gases exiting from the internal combustion engine, including an expansion chamber for closing phases of the variable choke device arranged upstream of said active noise reduction system and a cavity dispersing medium and high frequencies arranged downstream of the active noise reduction system. The expansion chamber for the closing phases of the variable choke device is integrated in a first depolluting system arranged upstream of said active noise reduction system.

Abstract: An exhaust gas muffler for an engine, the exhaust gas muffler having a body, at least one inlet for the exhaust gas from the engine on the body, a baffled chamber in the body to receive exhaust gas from the at least one exhaust gas inlet, at least one exhaust gas outlet from the baffled chamber to vent the exhaust gas from the baffled chamber, at least one fresh-air inlet on the body, a heat exchange conduit extending into the baffled chamber between the fresh air inlet and the at least one exhaust gas outlet, the heat exchange conduit being sized and shaped to permit heat exchange between the fresh air and the exhaust gas in the baffled chamber, and a fresh air outlet on the heat exchange conduit, the fresh air outlet being sized, shaped and located relative to the exhaust gas outlet to permit the fresh air to mix with exhaust gases being vented from the baffled chamber to lower an exit temperature of the exhaust gases.

Abstract: A sound producing vehicle exhaust system comprises a housing positionable over an exterior end of a vehicle tailpipe. A turbine has at least one support plate. The support plate is rotatable about a central axis of rotation with the housing and has a plurality of angular blades with interior ends coupled to the support plate for rotation there with. At least one facing disk is positioned within the housing adjacent to the turbine. A central axis is provided through the facing disk and support plate. At least one bearing pin is provided. The bearing pin rotatably couples the support plate to the facing disk. A plurality of apertures extend through the facing disk. In this manner exhaust gasses from a tailpipe will pass through the blades and create a turbine-like sound.

Abstract: A muffler exhaust tip for a vehicle having a muffler tailpipe includes a substantially hollow, cylindrical muffler tip member with an inboard end adapted to be affixed to the tailpipe and an outboard end. The hollow, cylindrical member is defined by an elongated outer sleeve and a coaxial, perforated inner sleeve which jointly define a baffle interspace therebetween. The inner sleeve carries a plurality of radially inboard protrusions to alter exhaust flow through the muffler exhaust tip. The perforated inner sleeve of the cylindrical member may define a pattern of holes. The baffle interspace may include a layer of fire retardant sound baffling material. The plurality of inboard protrusions define a helix extending through part of the inner sleeve in one embodiment. In another embodiment, part of the outer sleeve of the muffler tip includes a conical reducer such that the inboard end matches the dimensions of the tailpipe.

Abstract: The invention is an adjustable exhaust system and an adjustable insert for an exhaust system. The exhaust system includes a header flange, at least one conduit coupled to the header flange, a collector coupled to the conduit, and an adjustable insert for tuning engine performance.

Abstract: The invention concerns a suction muffler for a hermetically enclosed compressor with a housing that has at least a first and a second chamber, separated from each other by means of a division wall and connected with each other by means of a throttling channel, which is designed to allow flow from the first to the second chamber. The throttling channel includes a lateral opening, which opens into a chamber via a branch channel.

Abstract: A controllable muffler system is sued for use with an engine that produces a power by burning fuel. The system comprises a first passage section extending from the engine for having an exhaust gas of the engine flow therethrough. The first passage section has a catalytic converter mounted thereon. The system further comprises a dual passage section including second and third passage sections which extend separately from an end of the first passage section. The second passage has a control valve for controlling the flow rate of the exhaust gas flowing therethrough. The system further comprises a fourth passage section extending from respective ends of the second and third passage sections to the open air. The fourth passage section has a rear muffler mounted thereon. The system further comprises a control unit which controls the control valve of the second passage section in accordance with an operation condition of the engine.

Abstract: A device and method for muffling the sound from an internal combustion engine is described, wherein the device is a tube made of a suitable material such as rubber and is attached to the exhaust outlet of the vehicle. Further described is a method of muffling the sound of an internal combustion engine that is comprised of taking a length of tubing, having two ends and attaching one end of said tubing to the outlet of the exhaust of an internal combustion engine, and directing the other end of said tubing toward the ground surface, by forming an approximate ninety degree bend, such that this second end of the tubing is in close proximity with the ground surface, with the result that the sound level of the exhaust from the engine is substantially reduced.

Abstract: An exhaust stack cover sized to substantially conform and fit snugly, or elastically over the end and opening of the exhaust stack of a vehicle engine such that during transportation of the vehicle, wherein the engine is inoperative, a vacuum or air flow is prevented within the exhaust stack and thus the communicating turbine. Elimination of this vacuum and associated air flow prevents detrimental mechanical actuation of parts. Specifically the turbine shaft is protected, which is particularly susceptible to damage due to rotation without appropriate lubrication. The cover can be formed from a substantially heat resistant material such as neoprene which can withstand a substantial direct temperature by the exhaust stack as well as provide some elasticity in order to snugly and tightly grip the outside surface of the exhaust stack.

Abstract: A silencer for a muffler canister is designed to be insertable in the canister in order to reduce exhaust noise levels while providing rattle-and vibration-free operation. The device includes a series of flexible prongs mounted on the outer surface of the silencer that enable the silencer to securely fit within the canister.

Abstract: An exhaust pipe structure has, under a floor of a vehicle, an exhaust passage for exhaust gas discharged from a vehicle-installed engine, and at least one muffler is provided on an intermediate portion of the exhaust passage. The at least one muffler includes a main muffler having the greatest muffler capacity. An external cylinder forming an outer shell portion of the main muffler has a circular sectional shape having a diameter of 100 mm to 150 mm, or a sectional shape that is substantially equal to an area of the circular sectional shape. The external cylinder has a length of 800 mm to 12000 mm. The main muffler is disposed in a tunnel portion that is formed between the front wheels and the rear wheels.

Abstract: A chromed exhaust pipe and muffler for motorcycles that is capable of withstanding the extreme heat generated at high rpm's of a motorcycle engine without discoloring or “bluing”. A double wall construction is utilized for the exhaust pipe and muffler with the back side of the exterior chromed pipe cut away along the length of the pipe from the mounting flange to the muffler core. The cut-away exterior pipe is dimensional to allow the interior pipe to be inserted in one piece from the mounting flange to the muffler core, as well as cooling the exterior pipe, thereby preventing heat discoloration of the exterior chromed pipe. Spacers are welded to the interior pipe and the exterior pipe at the backside cut-away of the exterior pipe to space the interior pipe within the exterior pipe. The muffler core includes a baffle core enclosed by an interior pipe section, allowing gases to flow out the back end only. The interior pipe is spaced apart from and enclosed in the exterior chromed pipe.

Abstract: A muffler comprises a case having opposed ends closed; a partition structure installed in the case to constitute a sound silencing path; inlet and outlet pipes incorporated with the sound silencing path; and a sound shielding wall structure installed in the case to constitute a part of the sound silencing path.

Abstract: An exhaust pipe is branched into a right side connecting portion and a connecting portion. The right side connecting portion is connected to a first muffler while the connecting portion is connected to a second muffler through a space under a boundary between a driver's seat and a passenger's seat. It is possible to eliminate the need for reducing the thickness of a portion, corresponding to each of the driver's seat and the passenger's seat, of a cushioning material of the seat and to ensure a sufficient range of vertical movement of a rear wheel. The aforementioned arrangement permits the weight of the exhaust system to be reduced without sacrificing the cushioning characteristic of the seat and the range of vertical movement of the rear wheel.

Abstract: A bypass for an exhaust system for a utility vehicle, such as a combine, that, when substantially closed, provides maximum noise attenuation for road transport, i.e., relatively high back pressure, and then, when substantially open, would provide a reduced flow restriction, i.e., relatively low back pressure, for full power, field operation. A bypass flow path in an exhaust pipe is located upstream of a primary muffler. A diaphragm can be provided to manipulate a damper which acts to close the exhaust flow to the primary muffler and open the bypass to an exhaust pipe to effectively bypass the primary muffler.

Abstract: The present invention includes a power booster pipe suitable for attenuating sound associated with the intake or exhaust of an internal combustion engine and reducing pressure drop associated with movement of gases during operation of the engine. Generally, a diffuser portion is combined with an attenuation portion. One or more tubes of perforated material, such as steel and perforated flutes running the length of the tube increases the surface area of sound attenuating material exposed to combustion gases and the accompanying noise. The perforated flutes and tube can be encircled with sound reducing infill material. A low pressure drop design can be incorporated which includes a gradually increasing diameter tube utilized to route the combustion gases.

Abstract: In a vehicle rear body structure in which a muffler is disposed below a rear cross member disposed to extend transversely below a rear part of the body of a vehicle, a lower end portion 10 of the rear cross member 7 extends downwardly to substantially the same height of that of a lower end portion 4c of a rear bumper face 4a disposed rearward of the rear cross member. Accordingly, it is possible to prevent the generation of heat deformation by protecting from heat related effects from a muffler a lower end portion of a rear bumper which tends to easily heat deform.

Abstract: An auxiliary silencer system for connection with the exhaust system of an all terrain vehicle includes a fiberglass packed flow through silencer having a rigid elbow connected with the existing tail pipe and positioned by adjustable brackets transversely on the vehicle in alignment with the existing system.

Abstract: The present invention relates to noise reduction technology for controlling exhaust noise in internal combustion engines such as an automobile engine and/or noise in a duct of an air delivery system such as air conditioning systems, and more particularly, to an apparatus and a method for controlling exhaust noise in an internal combustion engine or noise in a duct of an air delivery system using a conduit bypass pipe having variable or fixed lengths and dual mufflers.

Abstract: An exhaust stack cover sized to substantially conform and fit snugly, or elastically over the end and opening of the exhaust stack of a vehicle engine such that during transportation of the vehicle, wherein the engine is inoperative, a vacuum or air flow is prevented within the exhaust stack and thus the communicating turbine. Elimination of this vacuum and associated air flow prevents detrimental mechanical actuation of parts. Specifically the turbine shaft is protected, which is particularly susceptible to damage due to rotation without appropriate lubrication. The cover can be formed from a substantially heat resistant material such as neoprene which can withstand a substantial direct temperature by the exhaust stack as well as provide some elasticity in order to snugly and tightly grip the outside surface of the exhaust stack.

Abstract: A muffler comprises a case having opposed ends closed; a partition structure installed in the case to constitute a sound silencing path; inlet and outlet pipes incorporated with the sound silencing path; and a sound shielding wall structure installed in the case to constitute a part of the sound silencing path.

Abstract: An exhaust pipe has a manifold; one end of the manifold is connected to a distal end of a connecting tube. Another ends of the manifold are extended with a left branch tube and a right branch tube. The left branch tube is connected to a first muffler tube and the right branch tube is connected to a second muffler tube. The feature is that an interior of a middle section of the manifold has a valve which is controlled by a controller. The valve controls the area of the opening of the left branch tube communicated with the first muffler tube and the area of the opening of the right branch tube communicated with the second muffler tube. The driver may control the variation of exhaust gas without needing to adjust the exhaust pipe. The noise may be reduced easily and the performance of acceleration is enhanced.

Abstract: An exhaust apparatus for a vehicle includes a spark arrester having a tubular spark arrester body assembled on a rear portion of a muffler connected to an exhaust pipe. A tail pipe is inserted in the spark arrester body and is mounted on the spark arrester such that exhaust gas flowing through the muffler is discharged into the atmospheric air from the tail pipe through the spark arrester, to carry out, expansion and contraction of exhaust gas in the spark arrester occurs to augment the sound reduction performance. An annular partition plate cooperates with an inner face of a spark arrester body to form a throttle path therebetween that is securely mounted on a tail pipe wherein a plurality of expansion chambers that communicate with each other through the throttle path are formed between the tail pipe and the spark arrester body with the annular partition plate disposed therebetween.

Abstract: In a double-wall tail pipe for an exhaust pipe of a motor vehicle exhaust system comprising an inner shell to be mounted on the exhaust pipe, an outer shell surrounding the inner shell and being supported thereon in spaced relationship to form an annular air space therebetween for conducting cooling air therethrough, a support structure provided with air passages is disposed between the inner and the outer shells in an area where the inner shell is seated on the exhaust pipe when the tail pipe is mounted on the exhaust pipe which support structure interconnects the inner and outer shells in an area which is spaced from the discharge end of the tail pipe.

Abstract: An acoustic absorber (10) comprises a housing or wall (11), defining an interior absorber chamber (12) connected by openings (13) to a duct (20) to reduce the sound in the duct (20). The natural frequency and impedance of the absorber (12) are variable, so that the absorber (12) can be adapted to a sound field in the duct (20) in a manner corresponding to the respective operating conditions. Such adaptation is achieved mechanically, for example, by an elastic membrane (15) for varying the volume of chamber (12), or thermally, for example, by a heating wire (14) or a wire braid (17).

Abstract: Dip-coated ferrite stainless steel sheet usable in the automobile exhaust sector, characterized in that it comprises a steel core with the following composition by weight: 10.5%≦chromium≦20% 0%≦aluminum≦0.6% 0.003%≦carbon≦0.06% 0.003%≦nitrogen≦0.04% 0%≦silicon≦0.6% 0%≦manganese≦0.6% 0%≦sulfur≦0.002% iron and impurities inherent in processing, and a metal coating deposited by dipping the strip in a molten metal bath containing in particular aluminum and at least one rare earth element: cerium, lanthanum, praseodymium, neodymium, mixed metal and/or yttrium.

Abstract: An arrangement having an auxiliary heater, a catalytic converter (12) for catalytic post-combustion of exhaust gas from the heater, a muffler (14) for damping of the noise caused by the exhaust gas, and an exhaust line for removing exhaust gas from the auxiliary heater. In order especially to devise an auxiliary heater in which the muffler and the catalytic converter can be installed relatively easily, the muffler (14) and the catalytic converter (12) are combined in sing module (10) that can be located on the exhaust line.

Abstract: The device for producing an overtone-rich, sporty exhaust sound of the exhaust system of a four-cylinder engine includes exhaust pipes with four manifold pipes, at least one front pipe and a tail pipe. The length and/or cross-section of at least one exhaust pipe differ from the length and/or cross-section of the other exhaust pipes. At least some of the exhaust pipes lead into a first, second and/or third collecting point.

Abstract: An exhaust pipe is branched into a right side connecting portion and a connecting portion. The right side connecting portion is connected to a first muffler while the connecting portion is connected to a second muffler through a space under a boundary between a driver's seat and a passenger's seat. It is possible to eliminate the need for reducing the thickness of a portion, corresponding to each of the driver's seat and the passenger's seat, of a cushioning material of the seat and to ensure a sufficient range of vertical movement of a rear wheel. The aforementioned arrangement permits the weight of the exhaust system to be reduced without sacrificing the cushioning characteristic of the seat and the range of vertical movement of the rear wheel.

Abstract: There is provided a double-walled structure for coupling to another double-walled structure. The coupling connects one female end portion of the one structure and one male end portion of the other structure together. The connecting requires only connecting of the outer walls of the structures together, providing an overlapping connection. The inner walls of the structures have a gap between their ends, when connected. Thereby the coupling of the structures is facilitated. The space between the inner wall and outer wall of the structure is occupied by an insulating material, such as a sound absorbing fibrous batting. The space between the male/female end portions for connection to a female/male end of another structure is filled by a seal, preventing loss of insulating material and providing insulation of the joint coupling the double-walled structures together. The structure can be used, especially, as a segment in a sound-absorbing ductworks system.

Abstract: A screen-type spark arrestor (34) may be efficiently and compactly mounted in a muffler (10). A tubular screen is coaxial with an exhaust pipe (24) and has a first end (36) axially spaced from the pipe and star-crimped closed, and a second end (38) axially overlapping the pipe in concentric relation and crimped thereto by a crimp ring (40). The combination is mounted as a modular component by a flange (22) closing the muffler housing (12).

Abstract: A muffler arrangement structure wherein the position of the muffler is lowered and the angle of bank for the case of being inclined is ensured. The muffler arrangement structure includes an engine suspended at a longitudinal midsection of the vehicle body. A front wheel is suspended at the front side of the vehicle body with a rear swing arm unit provided on the rear side of the vehicle body so as to be capable of a pivotal motion about the axis extending along the lateral direction thereof. A rear wheel is suspended on the rear swing arm unit and is rotated by a drive force of the engine, wherein the muffler for reducing the exhaust sound generated by the engine extends from the engine rearwardly of the vehicle body and is disposed directly below the rear swing arm unit.

Abstract: An adjustable muffler system for a combustible engine including a muffler adapted for connection with an exhaust pipe of an engine, a blocking tube configured to be removably inserted within the muffler, and latch means adapted to removably secure the blocking tube within the muffler. In other embodiments, the blocking tube can include various holes or slots and may be telescoping or fabricated from multiple pieces.

Abstract: A rear end surface of a muffler is inclined so as to extend in parallel to the ground (E) when an all terrain vehicle is leaned against a support with rear ends of a rear carrier and rear portions of two rear wheels in contact with the ground (E) for storage. The volume of the expansion chamber of the muffler can be easily increased without making the muffler touch the ground when the all terrain vehicle is leaned against a support and without requiring large-scale modification. Thus, the silencing ability of the muffler of the all terrain vehicle can be improved.