SailNet Community - Reply to Topic
Thread: zincs for Yanmar 2GMF Reply to Thread
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

  Additional Options
Miscellaneous Options

Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below

  Topic Review (Newest First)
11-16-2007 02:00 PM
I have a 3gmf

I was told that I needed to change out the zincs in the engine. This is a new (110 hours now) engine, fresh water cooled. I went to the dealer. He explained that the fresh water cooled engines do not have zincs. Period. Only the raw water cooled Yanmars have engine zincs.
11-15-2007 09:06 AM
trantor12020 I've had the pleasure of a Yanmar deputy service manager on my boat for some troubleshooting and I asked same question as I couldn't seem to find the anode/zinc. He told me they don't have it for 2GM20F. Not required.
11-14-2007 08:29 PM
AjariBonten Ah, that explains a lot, thanks. Very different from my experience.

That's what I LOVE about this place.
11-14-2007 08:27 PM
SailorMitch The heat exchanger sits right on top of the engine, starboard side. It's not something separate, although obviously you can remove it for cleaning, etc. But it's all cheek by jowel so to speak.
11-14-2007 03:06 PM
AjariBonten No, I wouldn't argue with you.

How about the heat exchanger though? Isn't that separate from the engine?, or am I misunderstanding the layout. My experience is mostly with BIG Cats (4108's, etc.), or marineized automotive gas engines.

It seems to me that I replaced the heat exchanger zinc more often than any.
11-14-2007 03:03 PM
SailorMitch Fred -- Sorry, but I'm going with Yanmar on this one. If the engine needed a zinc, they would've installed one at the factory. If you ever own a 2GM20F, fell free to install a zinc. Mine is 20 years old and surely would've fallen apart from galvanic corrosion by now if it were an issue.
11-14-2007 02:22 PM
AjariBonten Hmmmmmmmmm,

I may be way off, but it has been my experience that having dissimilar metals on the individual piece of equipment is only part of the problem.

I thought having dissimilar metals at alll in contact with seawater could be a problem.

Of course they may need to be electrically connected for it to be an issue; but in my experience, every piece of metal is electrically connected!

For instance, the heat exchanger might be bronze, the shaft stainless, the prop bronze, etc. etc. Even though the heat exchanger may not have direct connection to the engine, the potential (pun intended) is there.

I would retrofit a zinc in the heat exchanger if there is not a place for one.

11-14-2007 02:16 PM
Originally Posted by AjariBonten View Post
I'd take a good look at the heat exchanger though.

That should have a zinc.

Oops, doubled Dog's point.
The reason Yanmar techs have given me for no zincs is that Yanmar did not use dissimilar metals in the heat exchanger for the 2GM series. Trust me, my boat has a 2GM20F and I was going nuts trying to find the zinc when I first bought it. I then bought a Yanmar service manual clearly showing that the fresh water cooled engine does not have a zinc, but the raw water version does. I double checked my reading of the manual with the kind folks at both Torresen Marine and Mack Boring, as well as a couple of guys I trust online.
11-14-2007 01:58 PM
AjariBonten I'd take a good look at the heat exchanger though.

That should have a zinc.

Oops, doubled Dog's point.
11-14-2007 01:16 PM
lbdavis I second the opinion (fact) that 2GMF's have no zincs.
This thread has more than 10 replies. Click here to review the whole thread.

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

For the best viewing experience please update your browser to Google Chrome