Can I get some help have a 2005 Chaparral 256 with a 8.1 Volvo past couple of ttimes it would stall sometimes coming off plane not all the time but once in awhile. Today it ran great for over an hour then I come of plane and it dies. Locked up solid I know it had water in it so I pull the plugs and water comes out the starboard side second plug from the back. It has the Corsa exhaust but at the time I was running under the water. Non of the pliugs look like i compressed water so I don;'t think I damanged the tops of the piston. I know this can happen did it several years ago with a diffetent boat. So what do you think Exhaust manifold , head gasket ?

I disconnected my fuel pump and cranked it over several times with out plugs. No strange noises. I am going to reinstall the plugs and see what happens.

Thanks

Transom or prop exhaust? I have seen the flappers fail in the Y-pipe for prop exhaust allowing water to get into the cylinders.

It has the corsa at the time I was running thru the prop.

I have seen the flappers fail in the Y-pipe for prop exhaust allowing water to get into the cylinders.

Pull it apart and see if the flappers are gone.
While you have it apart water test the manifold assembled.
Do you have center rise exhaust manifolds ?
Often times the gasket between the elbow and the manifold starts leaking internally into the cylinders from corrosion build up over time.
I believe you can position the manifold on a bench , introduce water to it and see if you are getting any water dripping into a cylinder, they should be absolutely dry.

probably just came thru exhaust, but the 496 very weak and does not take much to reduce them to doorstop material...