Patent ID: 7503292

Claim:
A system ( 1 ) for supplying an air-fuel mixture to a two-stroke internal combustion engine ( 2 ), comprising a carburettor ( 3 ) having a throttle valve ( 4 ), with a throttle shaft ( 16 ) and a throttle valve lever ( 11 ) fixedly connected thereto, and a choke valve ( 5 ), with a choke valve shaft ( 22 ) and a choke lever ( 18 ) fixedly connected thereto, and a choke valve ( 5 ), said system further has a transfer passage ( 6 ) between a crankcase ( 7 ) chamber and a combustion chamber ( 8 ) of said engine ( 2 ), wherein a supply conduit for additional air ( 9 ) having an air valve ( 10 ) for said additional air, said supply conduit for additional air ( 9 ) being adapted to discharge the additional air into the top portion of said transfer passage ( 6 ), either directly through a check-valve or via a recess in an engine piston ( 26 ), during a portion of a cycle of said two-stroke internal combustion engine ( 2 ), characterised in that a spring actuated lever ( 15 ) is rotatably arranged on the throttle shaft ( 16 ) and connected to the throttle valve lever ( 11 ) via a spring ( 14 ), and said air valve ( 10 ) is controlled by said spring actuated lever ( 15 ) of the throttle valve ( 4 ) so as to try to affect an air valve opening state when said throttle valve opening state is affected, and in that the opening state of said air valve ( 10 ) is delimited by a choked state of said choke valve ( 5 ) regardless of the throttle valve opening state, through interaction between said choke lever ( 18 ) and said spring actuated lever ( 15 ).