Compression test won't tell you if water broke to oil and didn't effect cylinder, gasket, or head. If oil is not milky and it idles/runs smooth you're likely fine. Compression test and coolant system pressure test are better, but coolant pressure is not quick and easy on a boat motor. Run it hard a bit, turn off, check oil, let it sit a but, start it. If manifolds are cracked it may want to hydrolock on restart after running, and not start. Hard to be 100% sure but if that's all good then you're probably fine.
|