Patent ID: 7415949

Claim:
A cylinder ( 1 ) for a crankcase scavenged two-stroke engine, comprising a cylinder bore ( 2 ) with centre line ( 12 ) and on opposite sides of the cylinder located closed transfer ducts ( 3 , 3 ′), which cylinder ( 1 ) had an underside ( 4 ) essentially perpendicular towards the cylinder bore ( 2 ), intended to be connected to a crankcase ( 5 ) in a parting plane (A), a besides an inlet ( 8 ) for air/fuel mixture, the cylinder is provided with at least one inlet ( 9 , 9 ′) for additional air to the combustion chamber, which inlet for additional air runs through a cylinder wall ( 11 ) and via a recess in the piston and a transfer port ( 6 , 6 ′) leads down into the transfer ducts ( 3 , 3 ′), characterized in that said transfer ducts ( 3 , 3 ′) each have an upper section ( 3 a , 3 a ′) leading from the transfer port ( 6 , 6 ′) and in a tangential direction in relation to the cylinder bore ( 2 ) and is followed by an essentially right angled bend ( 3 b , 3 b ′) leading into a lower section ( 3 c , 3 c ′) leading into the parting plane (A), and at least the right-angled bend of each transfer duct is located on opposite sides of an exhaust duct ( 7 ) and during at least a part of the right-angled bend ( 3 b , 3 b ′) the transfer ducts approach each other.