I have a 1979 23' Oday with a 15hp OMC Saildrive and this is our first season with her. I am getting water in the engine cylinder after a few seconds of running when launched. Happened in June when first launched and i have been struggling with a marine mechanic who was too busy to get to the repair, and finally he had the boat repaired with a new head gasket, but he did say that the old gasket seemed fine, and when we launched this week (9/2!), she does the exact same thing. Runs for a few seconds and then locks up and we have water in the cylinder. I am not a mechanic, but fairly descent at understanding our motor and it's operation. I have no faith, or time to deal with the same mechanic, and will probably bring the boat home and start over. So, looking for ideas on what may be going on and where to start? Thank you,Dale