I've got a 120HP Mercruiser circa 1973.<br /><br />I bought the whole boat for $200 and have it running really well although she ain't pretty. I know the block froze with water in it last winter (hence the price) and I successfully fixed the external crack with JB Weld. <br /><br />However, when I take the boat out a slight amount of water is getting into the oil. It is only enough to show some swirls in the oil and barely discolor it. There is not a significant increase in oil volume. I'm almost positive it is an internal crack.<br /><br />The boat is not worth putting any money into (ie new engine or rebuild) so I intend to run it as is until it dies and then part it out. My question is what can I do to postpone the inevitable? I intend to change the oil often. Are there any additives, tricks or suggestions for prolonging the life of this old motor?<br /><br />Thanks in advance for your suggestions.
