I went to un-winterize my boat and have found rust all over my engine, and have seen things I have never seen before. towards the front of the engine, on the top of the block is a threaded hole, pic attached, it has some debris in it that I had not cleared out when I took the picture. Does anyone know what this is for or if is should be plugged/used?
1997 Mercruiser 3.0XL
Thank you
1997 Mercruiser 3.0XL
Thank you
