I have a Westerbeke 4-107 in my new (to me) boat. Upon checking the
pencil zinc on the heat exchanger, I found that it was not screwed into
the cap, although I could see zinc sitting in the orifice. Either it
was coroded away in the cap, or was not screwed into the cap properly.
Not sure which, although the cap was clean with no zinc residue in it.
I tried to grab the zinc with pliers, but it would not come out.
Finally, it fell into the exchanger. The heat exchanger is a horizontal
cylinder about 3" in diameter and is about 14" long, with the zinc
fitting at the 9 o'clock position. My questions a Is having zinc
scraps sitting at the bottom of the exchanger a problem? The opposite
end of the exchanger is fitted with a bolt in the center. Is the
purpose of this bolt to an access to clean out the exchanger? If so,
how is cleaning accomplished. Thanks in advance for any responses.

There is usually a cap at each end of the heat exchanger so you can
open it up and clean it out. The only problem with zinc crud in the HE
is that it will block off some of the passages. It needs to be cleaned
occasionally, mabe every 3-4 years, but just one pencil dropping in
there shouldn't be a problem. That is, unless the PO left a bunch in
there as well! The pencil in your case corroded off and got stuck in
the hole. Probably should have been checked / replaced earlier. If you
haven't done so since you've owned it, probably a good idea to remove
the HE and take it to a radiator shop to have it hot tanked and
pressure tested. Otherwise, remove any end caps and blast out with a
water hose.

Paul C wrote:
I have a Westerbeke 4-107 in my new (to me) boat. Upon checking the
pencil zinc on the heat exchanger, I found that it was not screwed into
the cap, although I could see zinc sitting in the orifice. Either it
was coroded away in the cap, or was not screwed into the cap properly.
Not sure which, although the cap was clean with no zinc residue in it.
I tried to grab the zinc with pliers, but it would not come out.
Finally, it fell into the exchanger. The heat exchanger is a horizontal
cylinder about 3" in diameter and is about 14" long, with the zinc
fitting at the 9 o'clock position. My questions a Is having zinc
scraps sitting at the bottom of the exchanger a problem? The opposite
end of the exchanger is fitted with a bolt in the center. Is the
purpose of this bolt to an access to clean out the exchanger? If so,
how is cleaning accomplished. Thanks in advance for any responses.

I don't know about the exchanger on this engine, but yes, they are designed
to be opened and cleaned out. I did the job on my Yanmars a few years ago
and it solved a running hot problem. In this case there are caps on both
ends with gaskets and o-rings. Once they are removed, the core slides out
(one took a little tap with a soft mallet). Hose it down, and replace
gaskets and rings with new. The biggest part of the job was dealing with
the anti-freeze.

I also did an old Westerbeke years ago, dealing with the same zinc problem
you have. It was a different engine, but the same sort of thing, cap comes
off to expose the core. I just pulled out the zinc crumbs and stuck the cap
back on, but I kinda wish I had cleaned it out more. Perhaps someone can
explain if on the 4-107 the core slides out as easy as it does on the
Yanmar, and what gaskets one should have on hand.

"Paul C" wrote in message
ups.com...
I have a Westerbeke 4-107 in my new (to me) boat. Upon checking the
pencil zinc on the heat exchanger, I found that it was not screwed into
the cap, although I could see zinc sitting in the orifice. Either it
was coroded away in the cap, or was not screwed into the cap properly.
Not sure which, although the cap was clean with no zinc residue in it.
I tried to grab the zinc with pliers, but it would not come out.
Finally, it fell into the exchanger. The heat exchanger is a horizontal
cylinder about 3" in diameter and is about 14" long, with the zinc
fitting at the 9 o'clock position. My questions a Is having zinc
scraps sitting at the bottom of the exchanger a problem? The opposite
end of the exchanger is fitted with a bolt in the center. Is the
purpose of this bolt to an access to clean out the exchanger? If so,
how is cleaning accomplished. Thanks in advance for any responses.

If the zinc is in contact with the metal on the bottom, it is still
working as a zinc and will slowly disintegrate. I wouldn't bother
opening up the heat exchanger just to retrieve it. You're more likely
to introduce more problems than you are solving.

On Sun, 24 Sep 2006 06:58:51 -0400, "Jeff" wrote:

Perhaps someone can
explain if on the 4-107 the core slides out as easy as it does on the
Yanmar, and what gaskets one should have on hand

The Westerbeke parts manual and service manual are good investments if
you are a D.I.Y. er or are cruising somewhere where parts are scarce.
Sorry, my Westerbeke is a generator engine or I would give some part
numbers.

4-107 used 2 different zincs. Need serial # of engine to get correct zinc.
Gordon
"Dick Locke" wrote in message
...
On Sun, 24 Sep 2006 06:58:51 -0400, "Jeff" wrote:

Perhaps someone can
explain if on the 4-107 the core slides out as easy as it does on the
Yanmar, and what gaskets one should have on hand

The Westerbeke parts manual and service manual are good investments if
you are a D.I.Y. er or are cruising somewhere where parts are scarce.
Sorry, my Westerbeke is a generator engine or I would give some part
numbers.

Thanks everyone - great info, I appreciate it.

Kieth & Jeff, only one end has an end cap.

Dick, I do have the Westerbeke Technical Manual (1975). It includes a
parts list, but although over 250 pages of good information, it leaves
much to be desired. For instance, the heat exchanger diagram doesn't
show a gasket and doesn't indicate that the end with the bolt comes
apart for cleaning (I'll bet it does).

The former owner gave me spare parts that include two different size
zincs. I was wondering why (thanks Gordon). The oil cooler diagram
doesn't show a zinc, but tomorrow, when I look, I'll bet there's
one on it.

Andina, I like your solution - no work involved.

I just got the boat. It was on the Great Lakes and I'm told not too
much attention is paid to zincs on fresh water. That's why I'm
checking them out now. I think what I'll do is not do any flushing.
I'll keep a close eye on the water temperature and take some action
when the boat comes out for the winter next month unless I have an
overheating problem.

Again, I really appreciate the advice and opinions. My last boat had
an Atomic 4 and was basic camping out in the features department. The
new boat is a whole new ball game. So many wires and mysterious boxes!

Paul C - in Connecticut