Abstract: A compression release mechanism for facilitating starting of an internal combustion engine includes a bimetallic disc disposed in a passageway that communicates at one end with the combustion chamber of the engine and at its other end with the atmosphere. When the engine is cranked over, the disc is relaxed in an open position so that compression pressure will leak around it to release compression within the cylinder. After the engine fires and begins running, the increase in temperature in the combustion chamber will cause the disc to flex to a closed position which blocks off the passageway to prevent loss of power during normal operation of the engine. The disc will return to its relaxed or open position when the engine is shut off due to the incoming fuel charge cooling the disc so that the passageway is once again open for starting.