Two-stroke engine comprising a muffler

An operating method for operating a two-stroke engine of an engine-driven tool with a muffler, in particular for a hand-held tool such as a chainsaw, hand-held circular saw or an angle grinder or for a small motorcycle, a boat engine and the like, wherein

• the muffler comprises a muffler inlet which is followed by a flow channel, so that
• the flow channel is attached to an outlet of a combustion space of the two-stroke engine by means of the muffler inlet,
• and wherein at least one overflow channel opens into the combustion space, via which fuel-air mixture enters the combustion space when a piston moveably limiting the combustion space is in the region of the bottom dead centre,
• wherein the flow channel opens into a first chamber on the channel end located opposite the muffler inlet,
• wherein furthermore a second chamber is provided,
• into which exhaust gas flows through a main outlet branched off the flow channel and out of which the exhaust gas flows through an outlet, wherein
• the flow channel between the muffler inlet and the first chamber is flow-favorably molded such that the exhaust gas flowing into the muffler inlet because of its mass inertia predominantly flows into the first chamber and following a charging of the first chamber flows back again and because of this a counterpressure is formed in or in the direction of the combustion space,
• characterized by at least the following steps over the stroke movement of the piston:
• opening of the outlet of the combustion space through a downward movement of the piston,
• opening of the overflow channel through further downward movement of the piston,
• forming of the counterpressure of the exhaust gas in the direction of the combustion space,
• closing of the overflow channel through an upward movement of the piston and
• closing of the outlet through further upward movement of the piston.