Where are engine zincs located?

[Alan Clendinen]

I recently bought a 1987 E-35 MK-3, that has a Universal model 25XP. Looking at the owners manual and Universal engine manual, I am unable to find any mention of where zincs for the engine are located. I assume there must be at least one zinc in the heat exchanger, but what about the engine itself? Any info on location, and size zincs required would be appreciated.
Alan

 

[Cory B]

Alan,

We don't have the exact same engine model as yours, but I believe there is only a zinc in the heat exchanger.

If you click "Resources -> Document Archives..." in the top menu above you should be able to find a manual for your engine.

 

[Alan Clendinen]

I already have the Universal engine manual, but it makes no mention of
Cory,
As I noted in my post, I have the Universal engine manual, but it makes no mention of zincs, nor does the E-35 manual.

Alan39]Alan,

We don't have the exact same engine model as yours, but I believe there is only a zinc in the heat exchanger.

If you click "Resources -> Document Archives..." in the top menu above you should be able to find a manual for your engine.[/quote]

 

[ref_123]

I know, I know! Hate to replace the damn thing...

It's a tough day and I just need to went, so while the content below is correct, please do not pay attention to the style

OK... The only zink on M-25 is in the heat exchanger (the tube with 2 hoses, typically attached to the back of the engine, over the transmission). If you have a standard issue exchanger, it should be somewhere around 2 to 3 inch in diameter and about 1.5 feet long. The zink is on the right bottom side of it and looks like a hex bolt sticking out, and typically its bronze (ours was painted over). Found it? If not, check the left side.

Close the seacock that lets the raw water in, and carefully unscrew that zink out. Mine works well with 7/16 socket wrench. Watch out - there is tons of sharp metal around, so watch your hands. If it's been long enough since the last replacement, you will only pull out a bronze head witout any traces of the actual zink. Or some zink ashes inside the head.

West Marine typically carries an assortment of these so-called "pencil" zinks. Find the one of the right size. Now, bring it to the boat and make sure the length is right, too! You may have to end up cutting a piece of tail of that zink off.

Now, put some teflon tape (or, better yet, plumber's paste) on the threads and screw the new zink in. Make sure it's tight or it will leak.

Phew! Done! Go get yourself a beer. And don't forget to open the raw water seackock before you start the engine next time...

Regards,
Stan

 

[treilley]

Alan, there is only one zinc and it is in the HE. The HE will have 4 hoses attached to it. Raw in and out, Fresh in and out. I would recommend that you removed the HE entirely and get it cleaned as this is one area of maintenance that gets neglected. I boiled mine last season and replace the zinc every spring. It is very common for zincs to break off and get clogged in the HE along with eel grass or whatever else gets by the sea strainer(if you have one)

Do not use West Marine zincs. They are cheap garbage made in China with questionable content. There is a post from Loren recently that links to the Catalina site to help determine which zinc your HE has as they can be different.

http://www.ericsonyachts.org/infoexchange/showthread.php?t=7419&highlight=catalina

Once you figure out which wrench size(mine is 9/16 wrench with 1/4" NPT), you can order that zinc from a reputable supplier like Hamilton Marine or Hansen Marine.

 

[mherrcat]

The threads on the zinc cap bolt should be tapered. You probably won't need Teflon tape or pipe dope. I don't use it on mine and it doesn't leak. Depending on the diameter of the HE the comment on having to cut off a small bit of the zinc is correct. I have to cut off about half an inch even on the OEM replacements I got from Featherman Enterprises (no longer in business.)

(FWIW the temperature sender on the engine is the same tapered thread arrangement and you should specifically NOT use Teflon tape or sealant there or the sender won't work.)

 

[Alan Clendinen]

Thanks for all the helpful info, guys.

Alan (E-35 MK-3 "Morning Star")

 

[treilley]

That thread is NPT or National Pipe Thread and it should not have any type of sealant applied to it. Even through it would likely cut through the sealant enough to ground, it is not needed to seal it in the first place. Just like the sending unit, it needs to be grounded to work.