O'Day 30 Yanmar YSB12
This past February after a good sail in good wind my son and I were getting ready to put the boat in the slip. As the wind was blowing hard I had to get on the engine hard to maneuver. Why backing off the throttle I heard a sickening metal sound and the engine stopped. The O'day cruised into the dock at a fast walking speed. The crunch sounded bad and I expected a hole in the bow. As it turned out, there was a little divit and nothing else. The old O'Day was impressively tough.
Over a matter of three months my son and I pulled the engine and rebuilt it. It had blown a head gasket and the rocker arm nuts were so loose it dropped the push rods. It now has a new cylinder sleeve, piston, rings, rod bearing, wrist pin bushing, seals, etc. It is back in the boat and running well. I was lucky. Parts and cost of the boom truck totalled $800.
The boat has a dripless seal. It was an exciting moment when I learned how those things work as I moved the engine away and the boat started to flood.
I have one remaining problem. It seems that the motor now wants occasionally to not stop and if left at an idle in neutral will increase in speed. Not all the time but occasionally. Any ideas? It starts easy first try. Runs fine under load.