Check your outboard internal anodes

[Russ]

the big question that comes to my mind is "how many hours are on that engine

You could plug something like this in to get diags
http://www.brpdiagnostics.com/honda-dr- ... iagnostic/

the OEM anode is aluminum alloy, not zinc

What I've learned is that zinc is used for saltwater and aluminum for brackish water.
So OEM might be targeting the middle of users. Aluminum in saltwater would deteriorate faster than zinc so you are doing pretty good for 19 years.

More here:
https://www.westmarine.com/WestAdvisor/ ... -Corrosion

BTW, if you don't have one, you can D/L Honda manuals here
https://m.marine.honda.com/owners/manuals

[adudinsk]

Yes. Agreed
I went to my local Merc. dealer, and he had NO IDEA what I was talking about
I gave him part numbers, said he never sold/saw these internal anodes
Called the supplier for the region, HE SAID he never saw/ sold them

Ordering online...
Will be the first thing I replace.
(hope they are not rotted in)


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[Russ]

Yes. Agreed
I went to my local Merc. dealer, and he had NO IDEA what I was talking about
I gave him part numbers, said he never sold/saw these internal anodes
Called the supplier for the region, HE SAID he never saw/ sold them

Makes you think that they are a lifetime part.
I'm no outboard expert, but again, I've never heard of these internal anodes, EVER. Yet they seem to be made to be easily replaced.

This guy replaces them EVERY YEAR. Strange that your dealer has never sold one. Again, it reinforces the idea that they are a lifetime part.

I would think that gunk and bio stuff buildup would hinder their effectiveness. Like insulating them from currents.
At the very least, cleaning them seems to be in order. I wonder if there is a way to clean the bio-junk from the inside of an engine's manifold without taking it all apart? Flushing with fresh water doesn't seem to be enough. Yet I don't want to damage parts with acids and corrosive liquids.

[adudinsk]

Yes, they are supposed to be replace every few years in fresh water, and sooner in salt.
The Merc. ones you MUST replace the entire cap/rubber seal/anode as they do not sell it any other way.
Other brands you can (as the video shows) only replace the actual anode.

My 75HP merc has 3 of the 2 on the block one up by the head. all are the same and attach with 2 bolts. (do not over tighten)

they are about $30us (+/-) each.. plus shipping.. handling.. duty..blah..blah..

Interesting enough the SAME anodes are listed for some Yamaha outboards.. although I am not inclined to believe it...

https://www.boats.net/product/mercury/804085A01
Unless the bolts are rotted in.. should be a trivial task. Much easier than an impeller for the water pump. (although that easy.. just a pain to do)



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[Russ]

https://www.boats.net/product/mercury/804085A01
Unless the bolts are rotted in.. should be a trivial task. Much easier than an impeller for the water pump. (although that easy.. just a pain to do)

The link says "COVER/ANODE KIT". I wonder if that's a kit for ALL the anodes? At $30 a pop, that seems pricey.

I just ordered an anode kit for my Suzuki and it included a bunch of anodes including the bottom plate under the motor mount that touches the water, for $27. And, it's magnesium which is preferred for fresh water.
https://www.defender.com/product.jsp?id=3945220

[dlandersson]

Link? Part numbers?

Yes. Agreed
I went to my local Merc. dealer, and he had NO IDEA what I was talking about
I gave him part numbers, said he never sold/saw these internal anodes
Called the supplier for the region, HE SAID he never saw/ sold them

Ordering online...
Will be the first thing I replace.
(hope they are not rotted in)


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[Russ]

Link? Part numbers?

Mercury

https://www.boats.net/product/mercury/804085A01

I order my Suzuki parts from

https://www.defender.com/product.jsp?id=3945220


This company seems to know the most about anodes and what type to use in your boating waters.
http://martyranodes.com/sites/default/f ... AT19_0.pdf

[DaveC426913]

One question still exists; does leaving the motor foot in the water increase anode deterioration? Would tilting it up be advisable?

I think it's a function of the motor running, but I don't know.

Regardless, it should not factor in to your decision of how to tilt the motor. There's a lot bigger factors going into motor stowage than the paltry cost of replacing what is - by design - a sacrificial part.

[Bobsquatch]

One question still exists; does leaving the motor foot in the water increase anode deterioration? Would tilting it up be advisable?
[/quote]



As far as leaving it in the water, that depends on if there is any stray current in your boat. In my old cabin cruiser the electrical system was a mess. Many previous owners. I had twin engines so twice the annodes and exposure. I was never able to clear the water (per design) with my stern drives. My anodes could barely keep up when plugged into shore power. The issue is potentially damaging to the parent metal if the annode is insufficient. Given the option, I would never leave it in the water to complete any potential circuit. Our boats' electrical system has always been suspect and none of our boats are getting any newer. Given the choice, never leave the engine in the water. Particularly if you are connected to shore power. If you have a compelling reason to, keep a good watch for annode deterioration and foot damage. Annodes get real cheap if you end up replacing the lower leg.

[adudinsk]

My outboard is a 2005 Merc 75HP
Its model 1F75412D3
The "KIT" is called in the Merc parts manual as a "COVER" which is the entire unit
Part 804085



The motor (mine) has 3 of them, use EzPartsWeb to locate where they go.. or poke around the outboard once you find one.

Full part number is 97-804085A01




Andrew

[adudinsk]

Also in regard to the stray electrical current..
Yes.. that can destroy anodes QUICK if your plugged into shore power, and have anything AC connected to your DC system..
ie Charger, etc..
that could cause a problem.

A Galvanic Isolate will fix this, (make your own.. a heat sink.. 2x 50Amp bridge rectifiers.. 2 led's for indicators to be legal.. total cost under $20,,... plus a case/box/etc as fancy or simple as you want)

[Russ]

Also in regard to the stray electrical current..
Yes.. that can destroy anodes QUICK if your plugged into shore power, and have anything AC connected to your DC system..
ie Charger, etc..
that could cause a problem.

A Galvanic Isolate will fix this, (make your own.. a heat sink.. 2x 50Amp bridge rectifiers.. 2 led's for indicators to be legal.. total cost under $20,,... plus a case/box/etc as fancy or simple as you want)

I don't have shore power, but this is fascinating stuff. I would so much build one myself rather than pay what commercial ones cost.
Would be cool to see a mod like this for $20.

I found more here https://www.boatus.com/expert-advice/ex ... -explained

[adudinsk]

Yes.. good post.
The galvanic isolators are STUPID expensive.

All they are is a heat sink, 2 50A (etc) bridge rectifiers, a case, wire, and if you want to be "legal" you have 2 LEDs (I would use a 1K ohm current limiting resitor in series with each) for indicators.

Took an old heatsink off a video card, had boxes of Bridge Rec's from my pinball machines, 10 min job.. hardest thing was mounting neat to the heat sink.






An old article



to add LED MONITORING...
use 2 posing LEDs with a current limiting resistor..220 Ohm/330 Ohm/1K Ohm etc.. connect each to in and out of DIY isolator.


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[Russ]

Got my "anode kit" Freshwater Magnesium version.

It's for Suzi 90+ but I think it will have what I need for my DF70.

I may have some extra parts, but I'm going to install what I can.

[adudinsk]

Lucky, your kit has JUST the anode for the engine block.. so you just replace the anode.. not the whole "cover"

Merc... no can do.. they ONLY sell the entire unit with anode.. I wish I could get just the anode.!

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