Abstract: An internal combustion engine (10), including a cylinder (15) with a cylinder wall (12) defining a combustion chamber (32), a piston (13) reciprocally disposed within the combustion chamber (32) a crankcase (16) including a crankshaft (11) rotatably disposed therein, the piston (13) being connected to the crankshaft (11) by a connecting rod (17), a first scavenger duct (3) extending between the combustion chamber (32) and the crankcase (16), the first scavenger duct (3) including a top port (31a) and a bottom port (31b), a fuel and air inlet channel (22) in fluid communication with the crankcase (16) by way of a piston ported fuel and air inlet port (23) so that the fuel and air inlet channel (22) delivers a fuel and air mixture to the crankcase (16), and an airhead channel (6) in fluid communication with the first scavenger duct (3) by way of a first piston ported air inlet port (7), characterized in that the fuel and air inlet channel (22) is in fluid communication with the airhead channel (6) so that the f

Abstract: An internal combustion engine (10), including a cylinder (15) with a cylinder wall (12) defining a combustion chamber (32), a piston (13) reciprocally disposed within the combustion chamber (32) a crankcase (16) including a crankshaft (11) rotatably disposed therein, the piston (13) being connected to the crankshaft (11) by a connecting rod (17), a first scavenger duct (3) extending between the combustion chamber (32) and the crankcase (16), the first scavenger duct (3) including a top port (31a) and a bottom port (31b), a fuel and air inlet channel (22) in fluid communication with the crankcase (16) by way of a piston ported fuel and air inlet port (23) so that the fuel and air inlet channel (22) delivers a fuel and air mixture to the crankcase (16), and an airhead channel (6) in fluid communication with the first scavenger duct (3) by way of a first piston ported air inlet port (7), characterized in that the fuel and air inlet channel (22) is in fluid communication with the airhead channel (6) so that the f

Abstract: A two stroke crank case scavenged two-stroke internal combustion engine, the engine including: —a cylinder (2) configured to reciprocatingly receive a piston (6) therein defining a combustion chamber (8), the combustion chamber comprising an ignition means (5) for igniting an air/fuel mixture and an exhaust port (40) for evacuating the exhaust fumes, —a crank case (3) including a crank shaft (18), —an indirect fuel supply system (4), such as a carburettor (12) or a low pressure fuel-injection system, for supplying fuel to the crank case (3) to be scavenged to the combustion chamber (8), —at least one transfer duct (20, 20?) each extending from the crank case (3) to at least one corresponding transfer port (21, 21?) for connecting to the combustion chamber (8), —additional air filling means (25, 24, 27, 23, 23?, 22, 22?,26, 26?) for at least partly filling the transfer duct/s (20, 20?) with additional air from the transfer port (21, 21?) towards the crank case (3), —and a direct injection means (7) for injecti

Abstract: A two stroke crank case scavenged two-stroke internal combustion engine, the engine including: a cylinder (2) configured to reciprocatingly receive a piston (6) therein defining a combustion chamber (8), the combustion chamber comprising an ignition means (5) for igniting an air/fuel mixture and an exhaust port (40) for evacuating the exhaust fumes, a crank case (3) including a crank shaft (18), an indirect fuel supply system (4), such as a carburettor (12) or a low pressure fuel-injection system, for supplying fuel to the crank case (3) to be scavenged to the combustion chamber (8), at least one transfer duct (20, 20?) each extending from the crank case (3) to at least one corresponding transfer port (21, 21?) for connecting to the combustion chamber (8), additional air filling means (25, 24, 27, 23, 23?, 22, 22?,26, 26?) for at least partly filling the transfer duct/s (20, 20?) with additional air from the transfer port (21, 21?) towards the crank case (3), and a direct injection means (7) for injecting fue

Abstract: A crankcase scavenged two-stroke internal combustion engine (1) having an additional air supply (2) arranged to its transfer ducts (3), connecting a crankcase volume (4) and a transfer port (5). There is at least one recess (6, 24) in a piston (7) arranged below a piston ring (10, 11), and further there is a flow channel (12; 13; 14) arranged in the piston or in a cylinder wall (29) of the engine cylinder (9), and the recess is arranged to register with the transfer port and the flow channel for certain first piston positions, i.e. to create a communication between the transfer port/s and the crankcase volume.

Abstract: A crankcase scavenged two-stroke internal combustion engine (1) having an additional air supply (2) arranged to its transfer ducts (3), connecting a crankcase volume (4) and a transfer port (5). There is at least one recess (6, 24) in a piston (7) arranged below a piston ring (10, 11), and further there is a flow channel (12; 13; 14) arranged in the piston or in a cylinder wall (29) of the engine cylinder (9), and the recess is arranged to register with the transfer port and the flow channel for certain first piston positions, i.e. to create a communication between the transfer port/s and the crankcase volume.