Zincs Needed on Freshwater to Saltwater Conversion?

[tulsag]

I am preparing to truck my Hunter 356 with a Yanmar 3GM30F enigine from a lake in Oklahoma to the Gulf Coast. Do I need to do anything with engine zincs since I am changing from freshwater to saltwater?

I've read other forum threads stating that Yanmar put cupronickel heat exchangers in all the fresh-water cooled GM series and do NOT need zinc's. To be safe, I'd change them anyway but, I've looked, I can't find ANY, anywhere!!!! The manual does not give a diagram.

If I'm now feeding it saltwater do I need zincs?

Any other saltwater changes I should make?

[Solitude]

Better call Yanmar and ask You need zincs in a 3GM30. There are different zincs for salt water than freshwater. I wouldn't take a chance. Call your dealer

[sck5]

I have a 3GM30F and you do NOT need engine zincs. Unless, that is, you have a raw water cooled engine, but if you had that you probably wouldnt have a 3GM30F. I also brought the boat from fresh water to salt water. You dont really need zincs on the prop shaft in fresh water though it is a good idea to have them. Get new zincs for the prop shaft and you will be OK.

I went through the same panic you did and researched this carefully. There IS a place in the engine to put a zinc but Yanmar says they dont need them because they make their heat exchangers out of an alloy that wont corrode. Do a google search on yanmar 3gm30f zinc and it will lead you to several places where you can read for yourself.