I am out to service a Eaton/ Generac generator. I was told it wouldn’t start last time power went out. I went to start the generator and it made a high pitch winding sound. The starter was engaged and moving the generator. Therefore I checked everything out and decided to remove valve cover. Once valve cover remover I rotated the engine, turning the fan. The exhaust valve didn’t move. Therefore I remove the valve and find the push rod jammed inside the cylinder. Finally I put generator back together after putting pushrod back into place. Engine wouldn’t start something due to something broke inside.