Patent ID: 7305938

Claim:
A stroke-variable engine comprising: a main connecting rod connected at one end to a piston through a piston pin; a subsidiary connecting rod which is connected to a crankpin of a crankshaft rotatably supported in a crankcase of an engine body and which is connected to the other end of the main connecting rod; a control rod connected at one end to the subsidiary connecting rod at a position offset from a connected position of the main connecting rod; and a pivot shaft which is rotatably supported in the crankcase so as to be rotatable about an eccentric axis parallel to the crankshaft and which is connected to the other end of the control rod so that a rotational power reduced at a reduction ratio of 1/2 is transmitted from the crankshaft to the pivot shaft, wherein a camshaft of a valve-operating mechanism mounted at an upper portion of the engine body and the pivot shaft are operatively connected to each other.