Two-stroke engine having a bypass branching from an air filter housing

A two-stroke engine including an engine in a portable handheld work apparatus, the two-stroke engine comprising:

• a cylinder having a cylinder wall;
• a piston mounted in said cylinder to undergo a reciprocating movement along a stroke path between top dead center and bottom dead center during operation of said engine;
• said cylinder and said piston conjointly delimiting a combustion chamber;
• a crankcase connected to said cylinder;
• a crankshaft rotatably mounted in said crankcase;
• a connecting rod connecting said piston to said crankshaft to permit said piston to drive said crankshaft as said piston reciprocates in said cylinder;
• at least one transfer channel connecting said crankcase to said combustion chamber;
• said transfer channel having a first end defining an entry window opening into said combustion chamber and a second end opening into said crankcase;
• an air filter having an air filter housing defining a clean space;
• a choke throttle unit for conducting essentially fuel-free air from said air filter;
• an air channel connected to said transfer channel for supplying said essentially fuel-free gas flow thereto from said choke throttle unit;
• a mixture-preparation unit for supplying an air/fuel mixture;
• said mixture-preparation unit being mounted downstream of said air filter;
• an inlet channel downstream of said mixture-preparation unit for conducting said air/fuel mixture into said crankcase;
• said choke throttle unit including:
• an independent choke housing defining choke channel communicating with said air channel;
• and, a throttle element adjustably mounted in said choke channel;
• and,
• said choke housing being attached to said air filter housing and said choke channel being connected to said clean space of said air filter upstream of said choke element.