R27 Yanmar Engine Zincs

[Skeeter]

Replaced the zincs 2 years ago and checked them last year. I had bought some short wrenches for removing them. This year I forgot if they come out clockwise or counter clockwise (since all the filters come out clockwise) and can not get enough leverage to remove them. What are you using to get stubborn zincs removed in tight spaces besides PB20 lubricant.

 

[Brian B]

The engine zinc bolts come out counter clockwise just like a regular bolt would. On the upper zinc I use a cut down box wrench and the lower one I use a socket with 3/8 ratchet. You may be over tightening them. I get about 3 months out of the lower one and 6 months on the top one.

 

[Skeeter]

Waited a day for the PB20 to soak in and finally got them off. My new zincs have a different thread count and the zinc thread is also different. Tried several dalers and Cascade distributors and they would have to order from Japan. Ordered thru Boat Zincs at $12.95 a pop. Beats the Yanmar dealer quotes of $42 ea. The bottom zincs is 90% left, the top zinc is about 20%. The tug is only in the water for 2.5 months and then in dry storage.

 

[ALICE J]

Yanmar Zincs have a different size nut that the Boat Zincs, both recommend new copper washers.

 

[Skeeter]

Found a nut that would go on the zincs and there were left over millings on the brass threads of the zincs I bought from Boatzincs. Wire brushed the threads and presto they work correctly. I thought I had SAE vs Metric differences. The Boatzincs have more threads and the zinc threaded end is smaller then Yanmars OEM zincs. It can be difficult to remove a zinc that has been totally wasted, but remains in the thread hole of the brass plug. So much for thinking you have correct spare parts without having the proper tools to fix the issue.

 

[Skeeter]

Since a post mentioned the bottom zinc goes first, mine was coated with a white oxidation powder which would make the zinc useless. When put in a vise and turned it crumbled. Replacing them yearly now, no matter the length. The previous owner of the tug, did not replace the engine zincs in a timely manner and corrosion created a leak at the end of the intercooler. Quotes on removing the engine, replacing the intercooler housing, retesting that and the heat exchanger went from $4k to $12K. Had it done in the winter for $4K.

 

[Brian B]

Sometimes the zincs look to be OK but give them a good squeeze between your fingers and they crumble. Too bad you had to go through that expense for a an item that costs a few $$. If you have a generator that should have a zinc also.

 

[GaylesFaerie]

I'm a new owner of a used 2012 R27 and looking at replacing the zincs on my Yanmar 4BY2 180. I'm curious, is there a way to get them out without splashing sea water over the outside of the engine and inside the bilge? If its unavoidable I was thinking maybe replace them after winterizing when the sea water is replaced with anti-freeze. GF

 

[scross]

I just replaced the engine zinks today in my Yanmar 4BY2-150. The old ones were from Boatzinks.com as were new ones.
https://www.boatzincs.com/yan120650-13420.html
These are the only true zink zinks on the boat, all the other “zinks” are aluminum. These zinks are in the same location as on the Yanmar 180 HP engine. The boat was winterized a week ago so any small leak is antifreeze. The engine zinks are a bear to reach - have to lay on my belly in the cockpit to get leverage. Used a 8” crescent wrench for the top zink and a 7/8” short box end wrench for the bottom.
Boat had been in salt water about 80 days since last replaced. Top one was 60% gone and bottom one was 90% gone. Switching to replacing them every year.

 

[SkookumR29]

We have an R29 (2011) with 6by2-260; I just replaced both engine zincs after a little less than 4 months in the Sound. Both were more than 50 percent eroded, so I am going to make a habit of checking and replacing every two to three months. If you wait to long, they begin to fall apart and chunks of zinc get deposited in the heat exchanger, possibly restricting flow. Replacement zincs are inexpensive in the big picture and on the R29, both are very easy to access.

 

[GaylesFaerie]

Thanks for your quick replies scross and SkookumR29! Very detailed and helpful. Replace in the spring it is!

 

[YukonRon]

I just changed the engine zincs on my Yanmar 4BY2-180 in our R25. For the top zinc I have a 24mm combination wrench that I cut in half with a grinder and use the box end. For the bottom zinc I use a socket and swivel on a 6 inch extension on a ratchet .
The 24mm wrench (or 15/16th) socket have always been a good fit. Now the new replacement zincs from the dealer have a slightly smaller head, maybe 23mm? Time take the zincs to the tool store to buy another wrench that fits. Just when I thought I had all the right tools worked out :roll:

 

[scross]

Ron,
The engine pencil zinks from Boatsinks.com do indead have a slightly smaller head. The reference is 23mm or 7/8”. The 7/8” wrench was a good fit

 

[rpmerrill]

Yup, the zincs can come in 23 or 24 mm wrench models. I have a cut down wrench for both.
I also have a socket (I forget, 23 or 24) that I cut down so it is only about 3/4 inch tall which really helped to bet in there and get the tight ones out. I also have a long closed end wrench that I can slip over the handle of the cut down wrench to increase my leverage. It took me a couple years but now I have a tool set for just about every engine zinc combination.

Also a box of band aids.

Speaking of zincs.... does anyone have a zinc in their mixing elbow? I just bought a new elbow (ugh) and it came equipped with a zinc. EXCEPT the zinc is installed in the fitting where the prop shaft seal water supply is connected. That leaves me wondering if my set-up is "kosher" or a previous owner modification?