The encased exhaust is a traditional aftermarket expansion chamber muffler system for a two stroke engine encompassing a duct fan/propeller. The propeller is mounted directly to the engine's driveshaft, eliminating reduction gears and belts allowing for more airflow and less weight. This eliminates the muffler and replaces the cage on a paramotor, allowing for more airflow through the funneled air duct. The configuration of these two functions exists but not in this sequence, that is what makes this product unique.

The encased exhaust is a traditional aftermarket expansion chamber muffler system for a two stroke engine encompassing a duct fan/propeller. The propeller is mounted directly to the engine's driveshaft, eliminating reduction gears and belts allowing for more airflow and less weight. This eliminates the muffler and replaces the cage on a paramotor, allowing for more airflow through the funneled air duct. The configuration of these two functions exists in a particular sequence.

A hedge trimmer has at least one cutting blade and an internal combustion engine operatively connected to the at least one cutting blade so as to drive the at least one cutting blade reciprocatingly. The internal combustion engine has an exhaust gas muffler with an outlet for discharging exhaust gases from the exhaust gas muffler. A multi-part exhaust gas pipe is connected seal-tightly to the outlet of the exhaust gas muffler and connects the outlet of the exhaust gas muffler to an outlet opening where the exhaust gases exit from the hedge trimmer. The multi-part exhaust gas pipe has a plurality of pipe sections, including at least a first pipe section and a second pipe section, wherein the second pipe section is embodied separate from the first pipe section. At least one of the plurality of pipe sections is made of plastic material.

A muffler (40) devised particularly for use with an engine of the type used on unmanned aerial vehicles (UAVs), and a UAV (10) having an engine (30) fitted with the muffler (40). The muffler (40) comprises a body (51) having an interior chamber (60). The muffler body (51) has a first end section (53) and a second end section (55). The first end section (51) is adapted for mounting onto the engine (31) by way of a first mount (81), with the interior chamber (60) in communication with an exhaust outlet of the engine (31) to receive exhaust flow therefrom. The second end section (53) is adapted to be mounted by way of a second mount (82) in a manner resisting movement with respect to the engine (31). In one arrangement, the second mount (82) is configured to yieldingly resist movement with respect to the engine (30). In another arrangement, the second mount (82) is configured to mount the second end section (55) under a preload resisting movement of the second end section with respect to the engine (30).

A muffler devised particularly for a small, reciprocating-piston two-stroke internal combustion engine of the type used on unmanned aerial vehicles. The muffler comprises a body incorporating an inlet, an outlet, and a plurality of chambers for exhaust gas flow from the inlet to the outlet. The body is configured to present a compact profile for installation on the engine. The chambers are so configured that adjacent chambers communicate to facilitate exhaust gas flow from the inlet to the outlet via flow passages. The various chambers comprise an inner chamber, an outer chamber, and one or more intervening chambers disposed between the inner and outer chambers. The various chambers are disposed one about another in annular formation. This arrangement creates a long flow path from the inlet to the outlet incorporating various directional changes.

A hedge trimmer has at least one cutting blade and an internal combustion engine operatively connected to the at least one cutting blade so as to drive the at least one cutting blade reciprocatingly. The internal combustion engine has an exhaust gas muffler with an outlet for discharging exhaust gases from the exhaust gas muffler. A multi-part exhaust gas pipe is connected seal-tightly to the outlet of the exhaust gas muffler and connects the outlet of the exhaust gas muffler to an outlet opening where the exhaust gases exit from the hedge trimmer. The multi-part exhaust gas pipe has a plurality of pipe sections, including at least a first pipe section and a second pipe section, wherein the second pipe section is embodied separate from the first pipe section. At least one of the plurality of pipe sections is made of plastic material.

An apparatus for adjusting power and noise characteristics of an internal combustion engine comprises a wall configured to define an engine cylinder that includes a bore and a compression relief passage. A compression relief valve is configured to selectively adjust fluid flow capacity of the compression relief passage. A manifold is configured to be in fluid communication with the exhaust passage and includes an exhaust bypass valve to permit exhaust to at least partially bypass a noise suppressor. Operational characteristics of the engine can be adjusted along a range that extends from a first set of operational characteristics present when both the compression relief valve and the exhaust bypass valve are in a fully open position to a second set of operational characteristics present when both the compression relief valve and the exhaust bypass valve are in a fully closed position.

A muffler (40) devised particularly for use with an engine of the type used on unmanned aerial vehicles (UAVs), and a UAV (10) having an engine (30) fitted with the muffler (40). The muffler (40) comprises a body (51) having an interior chamber (60). The muffler body (51) has a first end section (53) and a second end section (55). The first end section (51) is adapted for mounting onto the engine (31) by way of a first mount (81), with the interior chamber (60) in communication with an exhaust outlet of the engine (31) to receive exhaust flow therefrom. The second end section (53) is adapted to be mounted by way of a second mount (82) in a manner resisting movement with respect to the engine (31). In one arrangement, the second mount (82) is configured to yieldingly resist movement with respect to the engine (30). In another arrangement, the second mount (82) is configured to mount the second end section (55) under a preload resisting movement of the second end section with respect to the engine (30).

Provided are an engine and an engine work machine. An engine in which a substantially box-shaped muffler made by joining a partitioning plate with inner and outer housings is directly secured to a cylinder, wherein the center axis of the cylinder is slanted rearward at an angle. The muffler has the partitioning plate inclined from the cylinder-side upper corner part toward the opposing lower corner part; and the muffler is secured at three points, i.e., two screws near an exhaust port, and an attachment screw near the upper corner part. Exhaust gas is discharged so as to flow forward along the upper wall surface of the muffler from near the end that is close to the cylinder in the upper surface of the muffler, and the exhaust gas is diffused, with the front corner part (curved surface part) being shaped as a curved surface having a large radius of curvature.

A muffler devised particularly for a small, reciprocating-piston two-stroke internal combustion engine of the type used on unmanned aerial vehicles. The muffler comprises a body incorporating an inlet, an outlet, and a plurality of chambers for exhaust gas flow from the inlet to the outlet. The body is configured to present a compact profile for installation on the engine. The chambers are so configured that adjacent chambers communicate to facilitate exhaust gas flow from the inlet to the outlet via flow passages. The various chambers comprise an inner chamber, an outer chamber, and one or more intervening chambers disposed between the inner and outer chambers. The various chambers are disposed one about another in annular formation. This arrangement creates a long flow path from the inlet to the outlet incorporating various directional changes.