Patent ID: 7726271

Claim:
An engine comprising: a camshaft having opposite end portions between which intake and exhaust cams are formed, said camshaft being supported at said opposite end portions by cam supporting portions of an engine body; and a decompression device having a decompression camshaft and a decompression weight pivotably supported through a pivot shaft directly to said camshaft and adapted to be rotated at a predetermined angle by a centrifugal force generated during rotation of said camshaft, wherein said camshaft has a weight accommodating portion for pivotably accommodating said decompression weight between said opposite end portions, at least one end portion of said camshaft is supported through a ball bearing to said engine body, and the outer diameter of said decompression device is smaller than that of said ball bearing, wherein said decompression weight and said decompression camshaft are subassembled with said camshaft before inserting said camshaft into said engine body from one side thereof, and wherein said ball bearing is supported by a bearing support hole in said engine body, the size of the bearing support hole being greater than an outermost diameter of the camshaft and the decompression device, and said camshaft subassembled with the decompression device is inserted into said engine body through said bearing support hole.