Zinc replacement on Yanmar 3HM/3GM series
 

For those of you in southern salt water, how often
do you have to replace the zincs on your Yanmar?

We are on the Texas coast, and I'm wondering what
to expect, and how often I should be inspecting
the new zincs that were put in about a year ago.

TIA

Don W.

Zinc replacement on Yanmar 3HM/3GM series
 

Don:

There are no zincs on a Yanmar 3GM engine, at least not on the few I have
owned. The raw water heat exchanger has cupro-nickel tubes and Yanmar
obvously believes that they won't corrode enough to warrant zincs.

David

Zinc replacement on Yanmar 3HM/3GM series
 

David&Joan wrote:

Don:

There are no zincs on a Yanmar 3GM engine, at least not on the few I have
owned. The raw water heat exchanger has cupro-nickel tubes and Yanmar
obvously believes that they won't corrode enough to warrant zincs.

David


Funny, my GM series service manual has details of how to change the zinc
on 1,2 and 3GM and the newer 1GM10, 2GM20 and 3GM30 engines. If you
dont belive me google for yanmar "27210-200300". Now I'll agree that
the 3GM30F doesn't use this zinc but you were talking about 3GMs.

This isn't a lot of help to the OP, and I'd suggest having all required
spare gaskets, rubber washers & a spare zinc anode to hand then
inspecting it NOW after one year. If its more than 1/3 gone, inspect at
6 month intervaals in future. If its less than 1/2, replace now. Dont
forget to buy replacements for all spares used.

Keep one used zinc to block the hole in case you ever need to clean
out the block with Marsolve.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.

Zinc replacement on Yanmar 3HM/3GM series
 

Don (and Ian),
I'm away from my boat and it's 3GM30F manual, but two things . . . .
First, I know that my 30GM30F is the fresh water version with heat
exchanger, and it has no zincs. However, I am pretty sure that the manual
describes procedures for replacing zincs in the sea water cooled version.
Yanmar has an online forum and help desk which I have found useful,
Yanmarhelp.com.

Good luck,
Scott


"Ian Malcolm" wrote in message
...
David&Joan wrote:

Don:

There are no zincs on a Yanmar 3GM engine, at least not on the few I have
owned. The raw water heat exchanger has cupro-nickel tubes and Yanmar
obvously believes that they won't corrode enough to warrant zincs.

David
Funny, my GM series service manual has details of how to change the zinc
on 1,2 and 3GM and the newer 1GM10, 2GM20 and 3GM30 engines.
SNIP

Zinc replacement on Yanmar 3HM/3GM series
 

Scott wrote:

Don (and Ian),
I'm away from my boat and it's 3GM30F manual, but two things . . . .
First, I know that my 30GM30F is the fresh water version with heat
exchanger, and it has no zincs. However, I am pretty sure that the manual
describes procedures for replacing zincs in the sea water cooled version.
Yanmar has an online forum and help desk which I have found useful,
Yanmarhelp.com.

Good luck,
Scott
Yep, Yanmarhelp is a *very* good forum. I have a PDF copy of the manual
as well as the dead tree version which normally lives onboard so I was
able to check my facts. :-) Cant remember were I found the PDF or I'd
provide a link to it. :-(

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.

Zinc replacement on Yanmar 3HM/3GM series
 

Ian Malcolm wrote:

Scott wrote:

Don (and Ian),
I'm away from my boat and it's 3GM30F manual, but two things . . . .
First, I know that my 30GM30F is the fresh water version with heat
exchanger, and it has no zincs. However, I am pretty sure that the
manual describes procedures for replacing zincs in the sea water
cooled version. Yanmar has an online forum and help desk which I have
found useful, Yanmarhelp.com.

Good luck,
Scott

Yep, Yanmarhelp is a *very* good forum. I have a PDF copy of the manual
as well as the dead tree version which normally lives onboard so I was
able to check my facts. :-) Cant remember were I found the PDF or I'd
provide a link to it. :-(

Hi Ian,

I've got the "dead tree" (I like that :) version
of the service manual down at the boat also.
That's how I know where the zincs reside in the
engine. I'd imagine that for the FWC versions
they just plug the zinc holes with a cap.
Unfortuately my 3HM is raw water cooled.

I think that I'll do as you suggest and pull the
zincs to take a look at them. I was just trying
to get a feel from others how often they were
having to replace them.

If you find that PDF, I'd sure like a link to it :)


Later,

Don W.

Zinc replacement on Yanmar 3HM/3GM series
 

Don W wrote:


Ian Malcolm wrote:

Scott wrote:

Don (and Ian),
I'm away from my boat and it's 3GM30F manual, but two things . . . .
First, I know that my 30GM30F is the fresh water version with heat
exchanger, and it has no zincs. However, I am pretty sure that the
manual describes procedures for replacing zincs in the sea water
cooled version. Yanmar has an online forum and help desk which I have
found useful, Yanmarhelp.com.

Good luck,
Scott


Yep, Yanmarhelp is a *very* good forum. I have a PDF copy of the
manual as well as the dead tree version which normally lives onboard
so I was able to check my facts. :-) Cant remember were I found the
PDF or I'd provide a link to it. :-(


Hi Ian,

I've got the "dead tree" (I like that :) version of the service manual
down at the boat also. That's how I know where the zincs reside in the
engine. I'd imagine that for the FWC versions they just plug the zinc
holes with a cap. Unfortuately my 3HM is raw water cooled.

I think that I'll do as you suggest and pull the zincs to take a look at
them. I was just trying to get a feel from others how often they were
having to replace them.

If you find that PDF, I'd sure like a link to it :)


Later,

Don W.

Well I've searched for it and gone back over the download logs and I
belive the site (was on www.boten.nl) has taken it down, probably
because of the Yanmar copyright.

As such, I wont be posting it anywhere on the web and at some 66Mb its
rather too big for email (which I would only have considered to the
first 3 people who could prove they owned a dead tree copy - I've got no
desire to **** of my local Yanmar dealers). I seem to remember somebody
linking to it from a diesel forum which is probably why it vanished.

It was called YanmarGM&HMWorkshopManual.pdf and who knows it *might*
reappear somewhere. It appeared to be a slightly older version than the
current dead tree manual.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.

Zinc replacement on Yanmar 3HM/3GM series
 

"Ian Malcolm" wrote in message
...
As such, I wont be posting it anywhere on the web and at some 66Mb its
rather too big for email

Assuming you have a high speed connection, 66 Mb is easily do-able using
"sendthisfile,com" and probably as secure as most of the internet.
And again assuming you want to mess with it.
BF

Zinc replacement on Yanmar 3HM/3GM series
 

I was surprised to find a zinc in the block (cooling jacket) of my 3GM 30
freshwater cooled engine. I assume the blocks are the same and there is a
hole there that has to be plugged, so it seems they just use the same plug
with a zinc screwed on. Simplifies the assembly line not to have w/ or w/o
zinc, perhaps, or maybe mine was just a mistake.
Needless to say, the zinc was not eroded.
FWIW, mine is a European version.

"Scott" ASDF wrote in message ...

Don (and Ian),
I'm away from my boat and it's 3GM30F manual, but two things . . . .
First, I know that my 30GM30F is the fresh water version with heat
exchanger, and it has no zincs. However, I am pretty sure that the manual
describes procedures for replacing zincs in the sea water cooled version.
Yanmar has an online forum and help desk which I have found useful,
Yanmarhelp.com.

Good luck,
Scott


"Ian Malcolm" wrote in
message ...
David&Joan wrote:

Don:

There are no zincs on a Yanmar 3GM engine, at least not on the few I
have owned. The raw water heat exchanger has cupro-nickel tubes and
Yanmar obvously believes that they won't corrode enough to warrant
zincs.

David
Funny, my GM series service manual has details of how to change the zinc
on 1,2 and 3GM and the newer 1GM10, 2GM20 and 3GM30 engines.
SNIP

Zinc replacement on Yanmar 3HM/3GM series
 

Don W wrote in news:ZB9sh.17467
:

Unfortuately my 3HM is raw water cooled.


I know someone who has a raw water cooled Yanmar in the salt. He installed
a Y-valve in the hose just up from the through hull intake. The open side
goes to his fresh water pressure system.

When he's done with the engine, leaving the engine idle to keep the
thermostat open, he closes the through hull valve to shut off the seawater,
throws the y-valve to "FLUSH", and flushes the engine with pressurized
fresh water for a few minutes, even cleaning the salt out of the waterbox
muffler, then shuts down the engine that's been heating fresh water, now,
and switches the Y-valve back to "NORMAL", leaving the seawater valve off
until he needs the engine again. Works great! Zincs last forever! He
even flushes it on the hook.

Larry
--
Democracy is when two wolves and a sheep vote on who's for dinner.
Liberty is when the sheep has his own gun.