Seawater cooled diesel

[MikeHachey]

I recently purchased a sailboat with an 18 HP, 1988 2GM Yanmar diesel. The engine is seawater cooled only - no heat exchanger. Can I take this boat into a salt water environment without ruining it?

[michaelmrc]

i have a 1gm10 yanmar raw water cooled and i asked the same question to yanmar. they told me that these engines were designed to run in a raw water environment and that it would be a waste of my money to convert it over to a fresh water cooled system. this coming direct from yanmar bears a little credibility i think.

[unbusted67]

Absolutely, hence the them using the word seawater and not freash water to describe your cooling system. Cooling systems with heat exchangers are often called fresh water cooled. Make sure you have the proper zincs installed on your engine to avoid electrolysis. Your Yanmar manual should tell you where those are.

[steve_hendry]

I have the original 1980 3QM30 Yanmar in my boat. It's raw water cooled, and was in the saltier lower Chesapeake Bay until I brought it up here in 2003. It's fine.

[Solitude]

Yes.

They have a lower temperature thermostat. They are made for the environment. You could easily install a flushing T to flush the salt water out between trips. As unbusted stated: proper maintenance is key. Do you have a manual.

You can find links to one on the site.

Make sure you work the engine, don't baby it, maintain it well and it won't let you down. It should have max RPM at 3600 and cruising at 2600-3000.