My mechanic suggested I change the size of my thru-hull for the wet exhaust from 1.75" to 2.0". It appears the Sam L Morse company stepped the 2.0" exhaust coming off my 3GM30F down to 1.75" at the water muffler, and continued all the way to a 1.75" thru-hull. I'm really not sure why my boat was built this way, but perhaps someone on the forum could help with the reasoning/history? My mechanic said that Yanmar would not honor the warranty if the 2.0" is reduced at any point from the engine to the thru-hull. At any rate, the warranty is a moot point; however, I would like to ask the forum their opinion on the value of having a seacock located at the wet exhaust thru-hull?

Thanks...

Ahoy Traveler ,,, do you have a copy of Nigel Calder's book ? Maybe you would like to consult that for more info on your question ?

I also did install a ball valve on my 2" exhaust hose ,,,, for the reason , that if I wanted to close off ALL external sea water entries to the hull ,, I would be able to do that ... Many boats sink right at their docks ,,, because the owners did not close their sea cocks ,,,, go figure that out ,,,, including shaft log drips ,,,,

I remember that Latitude 38 owner sinking his boat at the dock in S F ,,, because the wind shoved water up his exhaust port ,,, and that water siphoned into his engine , which passed his valves and flooded thru his oil dipstick ,, that power photo boat sunk at the dock in Sausalito , S F ,,, so think things through ,,, there is reason for our "Out Here" Madness !

L O L ,,, we learning all the time ,,,, so Much V Good Advice can be researched right here in archives ,,,, Keep your questions coming ???

Douglas,

Thank you for responding, it sounds like I need to have a new ball valve installed at the thru-hull. I noted that you have a 2" exhaust hose, which makes the question of why I have a 1.75" even more intriguing. Also, check your private messages when you get a chance.