This happened several years ago. I was getting the drill ready to go for the day when I noticed that a plug was missing from the intake manifold of the deck engine.I looked through the tool box but could not find a 1/4 inch pipe plug so I put a grease fitting in it until I got bsck home that evening. as I was drilling suddenly the engine started surging slightly. I looked up and there was was my mucker pumping grease into the intake manifold. I laughrd when he said that he had never noticed that fitting before.