Engine zincs -Yanmar 6LYA-STP

[Lshulan]

On my 2002 Mainship 390 with a Yanmar 6LYA-STP, I was changing my engine zincs following the details and pictures from Stella Blue and wanted to double check the location of one as the fitting in the location as pictured on the stbd side at the bottom of the oil cooler (see photo from Stella Blue where in yellow it says “Starboard side Zincs” the yellow arrow at the very bottom directly below the letter”V” that is sideways is indicated as a zinc to be replaced). I added a red arrow to point to the “zinc” in question. Anyway on my boat there is a fitting but it has what appears to be a drain on it (see my pictures - one is a close up and the other is to show the overall location) and I imagine this is to drain the oil cooler. Anyone with this setup have any suggestions?

 

[DavidM]

That fitting in the second pic is definitely a drain. The zinc for the oil cooler is in the bottom, right at the front of the cooler.

I owned two boats with these engines, a MS 34T and a Pilot 34 and maintained them myself, so I know a thing or two about them.

David

 

[Lshulan]

David - thanks for the info, I will check tomorrow to try again to see if I can find that zinc. In the picture from Stella Blue, can you point out where on the bottom it will be?

 

[DavidM]

Bottom of the lube oil cooler and all of the way forward. You can’t see it in those pics.

David

 

[Bacchus]

Larry,
I agree w DavidM as mine is the same.
I find that the oil cooler (alum) anode ( fresh water) that wears the fastest.
I have measured clearance and have been able to use an anode the next size longer without any interference. It does seem to help with/ anode life.

 

[Duetto]

agree with david

zinc is at very bottom fwd in cooler. on our boat it wears out the fastest

 

[Lshulan]

I’m away until tomorrow and will check it out. Since I have several experts on this thread, let me ask another question. So all told, assuming I find this zinc, that would be a total of four (4) I replaced, two on stbd and two on port following Stella Blue details. I also have the ZF tranny Is four the correct number?

 

[Duetto]

we have 5 on ours: 2 on port side top of heat exchanger, 1 port side rear of heat exchanger, 1 starboard side bottom fwd of oil cooler (the one we've been discussing), 1, the big one near oil filter. we have an after market trans oil cooler which has 2.

 

[DavidM]

Some engines were delivered with none, 1 or two zincs on the transmission oil cooler. Besides that, there are two on the front of the main heat exchanger, one on the back, one on the aftercooler (aft starboard) and one on the lube oil cooler.

Yes the one on the oil cooler wastes the fastest, probably because it is always full of sea water- as it doesn’t drain.

David

 

[porman]

My heat exchangers only have the two at the front.

 

[boiler81]

So why are some delivered like mine without zinc plugs on the engine after cooler?��
I've heard fresh water boats didn't get em all, but making two engine variants doesn't make sense.

 

[Duetto]

i think you'll find from just reading this thread, that over the life of mainship, they used yanmars of multiple configurations. so the real question is "why did yanmar have so many different configs"? my guess would be sourcing the different addons from different vendors or different engineers.

 

[DavidM]

Some Yanmar engine components like the transmission cooler were sourced in the US for “A” labeled engines, such as 6LYA. The US assembler probably sourced these from different suppliers at different times.

I am a bit surprised at the aftercooler being different as that is definitely a Yanmar Japan sourced part.

David

 

[davidla]

Here is the engine manual shot of the zinc referred to.

 

[Duetto]

wow, that one is new to me. will ck this weekend.

 

[Bacchus]

Here is the engine manual shot of the zinc referred to.

My manual has the same listing but my 6LYA oil cooler has only one anode and it is consumed the quickest vs all others. I have been successful changing to the next longer (same dia rod) anode, after checking internal clearance with a screw driver.

 

[aviator7836]

Oil Cooler Anode Life

My manual has the same listing but my 6LYA oil cooler has only one anode and it is consumed the quickest vs all others. I have been successful changing to the next longer (same dia rod) anode, after checking internal clearance with a screw driver.

Hi Don,

How often do you find that you have to check/change the oil cooler zinc? More than once per season? I have not checked mine since changing them in late May and the boat now lives in salt water once again. Just wondering if I should look at that sooner rather than at the end of the season.

Thanks!
Doug

 

[Bacchus]

Doug
I would check it sooner. Nothing lost if it is in good shape... just reinstall after cleaning off. I'm in fresh water using AL anodes so not a good comparison. I have seen others in salt water report the same re: oil cooler wearing out first.

If it goes too long it is more likely to break off which isn't desirable.
With some checking you will zero in on the best frequency for your situation.

 

[Duetto]

i installed just before launch in april and just checked and was about 2/3 gone. we r in saltwater.

 

[Lollygag1]

My Yanmar tech said to check once a season and this seems to suffice. I have a check list of to dos and 3rd week of May is zincs. Not sure if location, engine use etc create more west but in 6 years I seem to see the same annual wear.

Suppose it never hurts to check twice a year not very hard

 

[davidla]

Does anyone use thread seal on their anodes? I know not to use tape but wondering if they leak routinely on the Yanmar. My westerbeke never needed any. About to do mine so will report back how many and where.

 

[davidla]

Just read the thread on this in the maintenance section. Will try without sealant first and see how it goes for leaks.

 

[davidla]

Just did my zincs. Here is a poor picture of the one underneath the fwd end of the oil cooler.
PS didn't use any thread sealer and no leaks