Patent ID: 7389754

Claim:
A system ( 1 ) for supplying an air-fuel mixture to a cylinder ( 2 ) of a two-stroke crankcase scavenged internal combustion engine, comprising a carburettor ( 3 ) having a throttle valve ( 4 ) and feeding an air-fuel mixture to an intake port of the cylinder, said system further has a transfer passage ( 6 ) between a crankcase chamber and a combustion chamber of the engine, and a supply conduit ( 8 ) for additional air ( 9 ) having an air valve ( 10 ) for the additional air, and said supply conduit for additional air ( 9 ) being adapted to discharge the additional air into the top portion of the transfer passage ( 6 ), either directly through a check-valve or via a recess in an engine piston, during a portion of a cycle of said two-stroke internal combustion engine, characterised in that said air valve ( 10 ) is controlled by said throttle valve ( 4 ) so as to affecting an air valve opening state when said throttle valve opening state is affected, and in that said air valve ( 10 ) is of a barrel valve type while said throttle valve ( 4 ) is of a butterfly valve type ( 4 ), wherein a shaft ( 21 ) of said throttle valve is provided with a throttle valve lever ( 22 ), which lever is interconnected with an air valve lever ( 23 ) via a spring and a spring actuated lever ( 25 ) moving the air valve lever via a rod ( 24 ).