According to an aspect of the present invention, it is possible to easily support a spark arrester and prevent an occurrence of damage or sound in the spark arrester due to the effect of an exhaust pressure or external vibration. In a spark arrester, at least a flange part is formed of a spring member. The flange part includes a bent part that is telescopically bent by elastic deformation in a direction along a flow of exhaust gas. The bent part is supported between a tail pipe and a muffler in a state where the elastic deformation of the bent part is allowed.

According to an aspect of the present invention, it is possible to easily support a spark arrester and prevent an occurrence of damage or sound in the spark arrester due to the effect of an exhaust pressure or external vibration. In a spark arrester, at least a flange part is formed of a spring member. The flange part includes a bent part that is telescopically bent by elastic deformation in a direction along a flow of exhaust gas. The bent part is supported between a tail pipe and a muffler in a state where the elastic deformation of the bent part is allowed.

The temperature of exhaust gas discharged from a compact air-cooled engine used as a power source for an engine-driven working machine is reduced. An engine has a muffler mounted directly to the exhaust opening of the cylinder, and a resin muffler cover covering the muffler. An exhaust gas restriction member is provided to a wall surface of the muffler, and two exhaust passages serving as outlets for exhaust gas are formed in the exhaust gas restriction member. The exhaust passages are arranged independent of each other, and the streams of discharged exhaust gas are discharged to be slightly separated from each other as the streams flow away from the exhaust openings. The separated streams of discharged exhaust gas form a negative pressure space between the streams promoting the introduction of a cooling air stream into the negative pressure portion. Thus, the temperature of the exhaust gas can be reduced.

The temperature of exhaust gas discharged from a compact air-cooled engine used as a power source for an engine-driven working machine is reduced. An engine has a muffler mounted directly to the exhaust opening of the cylinder, and a resin muffler cover covering the muffler. An exhaust gas restriction member is provided to a wall surface of the muffler, and two exhaust passages serving as outlets for exhaust gas are formed in the exhaust gas restriction member. The exhaust passages are arranged independent of each other, and the streams of discharged exhaust gas are discharged to be slightly separated from each other as the streams flow away from the exhaust openings. The separated streams of discharged exhaust gas form a negative pressure space between the streams promoting the introduction of a cooling air stream into the negative pressure portion. Thus, the temperature of the exhaust gas can be reduced.

A motor system includes an engine having one or more cylinders, an electronic control unit, an exhaust treatment system in fluid connection with and downstream of the one or more cylinders. The exhaust treatment system includes an exhaust line, a combustion zone downstream, a combustion ignition source in the combustion zone, a catalyst downstream of an in thermal communication with the combustion zone. A method of heating a catalyst during an engine cold start and a method of initiating regular operating conditions of an engine having one or more cylinders are also described.

According to an aspect of the present invention, it is possible to easily support a spark arrester and prevent an occurrence of damage or sound in the spark arrester due to the effect of an exhaust pressure or external vibration. In a spark arrester, at least a flange part is formed of a spring member. The flange part includes a bent part that is telescopically bent by elastic deformation in a direction along a flow of exhaust gas. The bent part is supported between a tail pipe and a muffler in a state where the elastic deformation of the bent part is allowed.

According to an aspect of the present invention, it is possible to easily support a spark arrester and prevent an occurrence of damage or sound in the spark arrester due to the effect of an exhaust pressure or external vibration. In a spark arrester, at least a flange part is formed of a spring member. The flange part includes a bent part that is telescopically bent by elastic deformation in a direction along a flow of exhaust gas. The bent part is supported between a tail pipe and a muffler in a state where the elastic deformation of the bent part is allowed.

The present invention relates to spark traps/arrestors that are unproved relative to those that currently exist. For example, the present invention relates to a spark arrestor/trap that comprises a plurality of features that allows sparks/embers to be more effectively extinguished. The spark trap/arrestor of the present invention has at least two of vanes, conical devices and u-turns that allows for sufficient oxygen and a tortured path that is sufficiently long so as to effectively extinguish sparks and/or embers that enter the system. Alternatively, the system relates to a spark arrestor that comprises all of vanes, conical devices and u-turns that allows for sufficient oxygen and a tortured path that is sufficiently long so as to effectively extinguish sparks and/or embers that enter the system. In one embodiment, the various parts of the spark arrestor can be separated allowing for easy cleaning of the system.

The present invention relates to spark traps/arrestors that are unproved relative to those that currently exist. For example, the present invention relates to a spark arrestor/trap that comprises a plurality of features that allows sparks/embers to be more effectively extinguished. The spark trap/arrestor of the present invention has at least two of vanes, conical devices and u-turns that allows for sufficient oxygen and a tortured path that is sufficiently long so as to effectively extinguish sparks and/or embers that enter the system. Alternatively, the system relates to a spark arrestor that comprises all of vanes, conical devices and u-turns that allows for sufficient oxygen and a tortured path that is sufficiently long so as to effectively extinguish sparks and/or embers that enter the system. In one embodiment, the various parts of the spark arrestor can be separated allowing for easy cleaning of the system.

A separation device for separating a cyclone chamber from a collection chamber of a cyclonic separator has a guide member that includes a leading end, a trailing end, and a guide surface. The guide surface guides debris entrained in an airflow in the cyclone chamber in a helical path about an axis of the separation device and into the collection chamber. The guide surface extends about the axis of the separation device through an angle of less than 360 degrees for allowing debris in the cyclone chamber to also pass into the collection chamber from the cyclone chamber in an axial direction. The leading end of the guide member is at an angle between 30 and 60 towards the cyclone chamber with respect to the axis of the separation device to promote a helical flow of air and debris flowing over the guide surface.