I am looking for some advice for an 1986 O'Day 26 with a Yanmar 1GM10 (C) which I bought last Fall. The engine (2008) ran away ( not over 3500 rpm) and we think the block may well have a crack. After careful inspection wear limits etc. , we rebuilt the engine and it still ran away. 1. Is it possible that the breather is causing this? It seems a very simple mechanism. 2. If not, are new blocks or remanufactured Yanmar 1GM 10 engines available? 3. Has anyone repowered an O'Day 26 with a new diesel? I am 76 now and have dreamed all my life of having a sailboat like this. I have spent the last year fixing the trailer and boat and do really appreciate your advice. I am naming the boat Solar Harvest.