Automatic compression release mechanism for an internal combustion engine

In an internal combustion engine having an exhaust valve, an exhaust valve lifter, a camshaft having a shaft portion with a cam surface engaged by the exhaust valve lifter to open the exhaust valve at a first angular position of the camshaft;

• a compression release mechanism comprising:
• an actuator attached to slide longitudinally along the camshaft and including a cam portion, the actuator having a first position at which the cam portion is adjacent to the cam surface and engaged by the exhaust valve lifter to open the exhaust valve at a second angular position of the camshaft, and having a second position at which the cam portion is remote to the cam surface so that the exhaust valve is closed at the second angular position of the camshaft;
• and
• a weight lever pivotally attached to the camshaft and pivoting about an axis which intersects the shaft portion, the weight lever engaging the actuator wherein pivotal movement of the weight lever in response to engine speed causes the actuator to move along the camshaft between the first and second positions.

In an internal combustion engine having an exhaust valve, an exhaust valve lifter, a camshaft having a cam surface engaged by the exhaust valve lifter to open the exhaust valve at a first angular position of the camshaft;

• a compression release mechanism comprising:
• a weight lever having a pair of arms with the camshaft extending therebetween and a cross member connected between the pair of arms, the pair of arms being pivotally attached to the camshaft;
• and
• a slide actuator slideably attached to the camshaft and including a cam portion, the slide actuator having a first position at which the cam portion is proximate to the cam surface and is engaged by the exhaust valve lifter to open the exhaust valve at a second angular position of the camshaft, and having a second position at which the cam portion is remote to the cam surface so that the exhaust valve is closed at the second angular position of the camshaft, the slide actuator further having a pair of projections each engaging a different one of the pair of arms wherein pivotal movement of the weight lever produces movement of the slide actuator between the first and second positions.