I also can only find two spark plugs? As you can see I know nothing about tractors and little about engines. I do however have a state HVACR license if anyone needs AC advice bout all I have to offer. Anyways, this plug in the picture here doesn't look like it is in too good of shape. Maybe this is the problem? How would I know if it is sparking inside the engine? I beleieve these plugs are pretty cheap can I just removed and replace it? Do you drain the oil first?