Patent ID: 7552706

Claim:
An automatic decompression mechanism for selectively actuating a valve mechanism of an engine to reduce the compression pressure in a combustion chamber while starting the engine, said decompression mechanism comprising: a cam gear having a first side and a second side, said first side defining a cam profile surface for driving said valve mechanism, said second side having a slot region disposed therein, said slot region having an opening communicating with said cam profile surface; a centrifugal member disposed on the second side of the cam gear, said centrifugal member having a projecting portion, a pivot portion and a weight portion, said pivot and projecting portion being pivotally received within said slot region; a cover member mounted to said second side of said cam gear; a biasing means integrally formed from a portion of said cover member, said biasing means adapted to urge said centrifugal member into a decompression position when said cam gear is rotating at a lower speed, wherein under the action of a lower centrifugal force, said weight portion is positioned proximate an inner portion of said cam gear causing said projecting portion to project through said opening and above said cam profile surface, thereby causing said projecting portion to temporarily actuate said valve mechanism; and wherein said centrifugal member pivots to a non-decompression position when said cam gear is rotating at a higher speed, wherein under the action of a higher centrifugal force said weight portion is positioned proximate an outer portion of said cam gear causing said projecting portion to recede below said cam profile surface, thereby preventing said projecting portion from actuating said valve mechanism.