90 Etec Corrosion from Stainless propeller???

[Bobpen]

I think my stainless propeller may have caused catastrophic corrosion in the power head of my 90 Etec after 400 hours.
Can anyone confirm this???
It cost me $16,000 to replace the whole motor.

[Noelm]

I doubt it, there might be something going on, but it's not the prop.

[Bobpen]

I doubt it, there might be something going on, but it's not the prop.

I have some aluminium in a jar of salt water with some stainless bolts and it is fizzing.
The corrosion could only occur when the motor was actually running in salt water as is was always hot flushed with fresh water and stored dry.
Hot sea water in the power head plus Stainless is the only reason I can see.
The batteries were always isolated when stored so no stray currents.
It is a fibreglass hull.

[Noelm]

There's millions of boats with stainless props, you have "something" happening, no doubt, how old is the motor (not hours)

[stevej]

Many offshore or bass boats using a etec run a stainless prop
same as nearly every other brand

could be anything at play with your outboard and you don’t say how old it is
Poor servicing and not replacing annodes
incorrect wiring faulty wiring
moored boat

there's stainless bolts holding the thing to you hull as well and they havnt dissolved off I bet

I’m not a etec fan but I bet the prop had nothing to do with it

[Noelm]

Let's go right to the beginning, is the motor corroded from the inside out? is the paint bubbled on the outside? are all the bolts and bits and pieces rusted away too? is the corrosion limited to a certain part of the motor? do the anodes get replaced regularly? is the boat used in salt water only?

[shaungonemad]

I think my stainless propeller may have caused catastrophic corrosion in the power head of my 90 Etec after 400 hours.
Can anyone confirm this???
It cost me $16,000 to replace the whole motor.


There are probably a hundred stainless parts on a motor and the prop is the cause? The prop has a rubber bush that would insulate anyway.


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[stevej]

There are probably a hundred stainless parts on a motor and the prop is the cause? The prop has a rubber bush that would insulate anyway.


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and its greased on top of that

[Bobpen]

!3 years old. Looked immaculate until engine mounts failed.
Yearly leg oil change turned to $16,000 new engine.

[Bobpen]

and its greased on top of that
The corrosion must have occurred when motor was running.
The connection was the hot seawater in the power head.

[Bobpen]

Let's go right to the beginning, is the motor corroded from the inside out? is the paint bubbled on the outside? are all the bolts and bits and pieces rusted away too? is the corrosion limited to a certain part of the motor? do the anodes get replaced regularly? is the boat used in salt water only?
The boat is used in salt water only.
The corrosion was only in the power head. The outside of the motor was immaculate.
The magnesium anodes were lightly corroded.
The Power head acted as an anode for the stainless propeller.
Look at the chemistry of galvanic corrosion.
My new motor has an Aluminium Propeller.
.
T

[Noelm]

I don't doubt for one minute you didn't have corrosion in a 13 year old salt water motor, but, I don't think/believe/can agree that the propeller caused it, there is literally dozens of stainless components on your motor besides the prop, and there is millions of outboards (including e-tecs) that have stainless props and are perfectly OK.

[Bobpen]

I don't doubt for one minute you didn't have corrosion in a 13 year old salt water motor, but, I don't think/believe/can agree that the propeller caused it, there is literally dozens of stainless components on your motor besides the prop, and there is millions of outboards (including e-tecs) that have stainless props and are perfectly OK.
I hope my experience saves someone else.
The dealer called it before we pulled the power head. It might be more common than you know.

[stevej]

What your saying does not make sense
look at how many thousands of engines are sold with stainless props and are now being sold at 10-15 years old without the issues you have

your barking up the wrong tree blaming the prop in this instance
manufacturing defect or poor maintenance and servicing

[shaungonemad]

https://media3.giphy.com/media/3bb0hXCXiVehYbSd5r/giphy.gif


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[gazza2006au]

You have said more than once that it has happend while the engine is in salt water i bet if u put that engine back in salt water and used a multimeter attaching the black to the hull and red to a clean bolt on the engine u would have a positive reading meaning someone has incorrectly wired your engine and u have positive power flowing through the etec your etec is acting like a mentoss in coke

I think a decent mechanic could have rectified it if caught early, one of your tiny red power wires must have been earthed to the engine block to product a lowcurrent of power to slowly eat away the outboard

I rebuilt a 1998 25hp 4 stroke mercury many years ago and i just winged the electrical harness i just assumed the plugs were color coded, we took the boat out into salt water and i heard crackling, zipping,and fizzing i took the boat home and the paint on the bottom of my transom mounts were stripped of paint, i downloaded the manual and i had the tilt trim wires connected in wrongly i had a positive power reading through the block, i correctly wired it and it ran find after that

[Bobpen]

What your saying does not make sense
look at how many thousands of engines are sold with stainless props and are now being sold at 10-15 years old without the issues you have

your barking up the wrong tree blaming the prop in this instance
manufacturing defect or poor maintenance and servicing

Not a trace of corrosion anywhere except in the power head.
Anodes slightly corroded.
Stored on a trailer.
Fibreglass hull.
Hot flushed with muffs every use plus some extras to check it was starting OK.
Batteries isolated.
What maintenance could I possibly have done?
The dealer said it was common and he sees a lot of outboards.
Look at Magnesium, Zinc, Aluminium and Stainless and Galvanic corrosion.
The issue is not a problem for me as my new outboard has a Aluminium propeller.
If people listen to you will you buy them a new outboard when they have problems?
Free advice is worth what you pay for it.

[Bobpen]

What your saying does not make sense
look at how many thousands of engines are sold with stainless props and are now being sold at 10-15 years old without the issues you have

your barking up the wrong tree blaming the prop in this instance
manufacturing defect or poor maintenance and servicing

Always hot flushed with muffs every use plus some extras to check is was starting OK.
Stored on Trailer.
Fibreglass hull.
Batteries Isolated.
No trace of corrosion anywhere visible.
The dealer said it was common.
Not my problem now as my new motor has an Aluminium propeller.
My conscience would trouble me if I told people Stainless propellers were safe.
Still that isn't your problem.
Look at galvanic corrosion Magnesium, Zinc, Aluminium and then Stainless steel.
The aluminium and stainless in the salt water in my glass jar are still fizzing away at room temperature.
I don't need to heat them in a power head.

[Funchy]

Interesting bit of info -


https://www.boatus.com/expert-advice/expert-advice-archive/2012/july/types-of-marine-corrosion (https://www.boatus.com/expert-advice/expert-advice-archive/2012/july/types-of-marine-corrosion)

Galvanic corrosion is an electrochemical reaction between two or more different metals. The metals must be different because one must be more chemically active (or less stable) than the others for a reaction to take place. When we talk about galvanic corrosion, we're talking about electrical exchange. All metals have electrical potential because all atoms have electrons, which have an electrochemical charge.
Galvanic corrosion of the more chemically active metal can occur whenever two or more dissimilar metals that are "grounded" (connected by actually touching each other, or through a wire or metal part) are immersed in a conductive solution (any liquid that can transfer electricity). Anything but pure water is conductive. Saltwater, freshwater with high mineral content, and polluted freshwater are very conductive, and conductivity goes up with water temperature. That's one reason why boats in Florida experience more corrosion than boats in Maine.
The simplest example of galvanic corrosion, and the most applicable, is an aluminum lower unit with a stainless steel propeller. The aluminum is the more chemically active metal (the anode), and the stainless steel is the less chemically active metal (the cathode). Several things happen at the same time:

[Bobpen]

The wiring is was all original.
If I wanted to secretly destroy an outboard I would simply replace the zinc anodes with stainless cathodes and let bit fizz.
See where I am going here?

[shaungonemad]

Always hot flushed with muffs every use plus some extras to check is was starting OK.
Stored on Trailer.
Fibreglass hull.
Batteries Isolated.
No trace of corrosion anywhere visible.
The dealer said it was common.
Not my problem now as my new motor has an Aluminium propeller.
My conscience would trouble me if I told people Stainless propellers were safe.
Still that isn't your problem.
Look at galvanic corrosion Magnesium, Zinc, Aluminium and then Stainless steel.
The aluminium and stainless in the salt water in my glass jar are still fizzing away at room temperature.
I don't need to heat them in a power head.

I’m still struggling to understand why the prop is the problem, there are still plenty of other stainless parts on the motor.


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[Noelm]

No paint bubbling? no other bits corroded through? then I think something else was going on, I don't care what the dealer told you.

[stevej]

You havnt said if it was serviced properly by a dealer

Anodes are designed to break down they can become coated with minerals over time and need a scuff or roughing up to keep working
If they are still full size after many years then there’s your problem

the anodes offset any minor dissimilar metals issues funchy


your theories in stainless props is debunked by how many thousands of engines run stainless props and don’t dissolve power heads

[billfisher]

The wiring is was all original.
If I wanted to secretly destroy an outboard I would simply replace the zinc anodes with stainless cathodes and let bit fizz.
See where I am going here?

Have you checked to see what your prop shaft is made from? If it's stainless steel as well then that put's your prop theory to rest. Also stainless steel forms a protective oxide coating which means in practice it's corrosive effect on less noble metals is lower than it's position on the galvanic table would suggest:

file:///C:/Users/Philip/Downloads/galvanic_corrosion_mby.pdf

[stevej]

Pretty sure the drive shaft is stainless too

If you have serviced it yourself and not replaced the anodes or not noticed them deteriorating then you have your answer

https://www.operatorsguides.brp.com/OperatorsGuidesAttachments/OwnersManuals_EJ/attach/2012/216071%20EN.pdf

[Greg P]

Surely has to be more anodes on an Etec that what is in the manual you linked? Do they have them in the block's cooling passages as well like most engines?

[stevej]

It’s all I could find
It’s just a gearbox guide I think and not model specific
my etec detonated before its first service so didn’t get that far involved with it lol

but any engine will dissolve if annodes arnt replaced

[scottar]

Just entertaining the theory for a second, can you explain why the prop would have eaten out the powerhead instead of the gearbox anode directly in front of it or the aluminium in the leg right next to it. Your mechanic is an idiot or a blatant lying crook if that is what he is telling you.

[Noelm]

Yep, kind of agree, I have seen hundreds of boats with stainless props sitting in salt water, and not one ounce of "fizzing" to be seen.

[Bobpen]

What your saying does not make sense
look at how many thousands of engines are sold with stainless props and are now being sold at 10-15 years old without the issues you have

your barking up the wrong tree blaming the prop in this instance
manufacturing defect or poor maintenance and servicing
I have solved my problem. I have an aluminium propeller. You can take your chances, Not my problem.
My anodes were corroding nicely thanks.
The 400 hours were only the hours the engine was running the time fishing at anchor could be 4 times that lets say 1,600 hours with hot or warm seawater in the power head.
Same as being moored for 2 months in seawater.
Anodes cannot protect against corrosion caused by stainless just look a the electron flow.
Feel free to use stainless propellers.
If I sold outboards I would recommend them.
Anyone else be warned your anodes won't protect you.

[Bobpen]

Yep, kind of agree, I have seen hundreds of boats with stainless props sitting in salt water, and not one ounce of "fizzing" to be seen.
Hard to see corrosion in the power head. You should try.
If people want to take the risk of using a Stainless prop good for them.
My new motor is much more refined than the Etec.
Since 1970 I have worked with outboards, inboards, jet boats and a hover craft and never seen corrosion like this.
Of course the only one with massive corrosion happens to have a stainless prop.
Huge coincidence that Zinc anodes don't protect against Stainless then?

[Bobpen]

Just entertaining the theory for a second, can you explain why the prop would have eaten out the powerhead instead of the gearbox anode directly in front of it or the aluminium in the leg right next to it. Your mechanic is an idiot or a blatant lying crook if that is what he is telling you.
The seawater in the powerhead is hot and the water flow would keep the surface fresh for more corrosion.
My dealer had nothing to gain.
He predicted the corrosion before we pulled the powerhead off. Previous experience?
The corrosion was massive and the anodes were only mildly corroded.
We were going to patch the water jacket but the engine mounts were beyond patching and had already cracked.
I don't have a problem with stainless props as I no longer own one and never will.

[Bobpen]

Avoiding MerCruiser Bravo 3 Outdrive Corrosion Problems on Boats | My Boat Life (https://www.myboatlife.com/2013/03/avoiding-mercruiser-bravo-3-outdrive.html)

[stevej]

So did a dealer service it or not, simple question
400 hours in salt according to etecs manual states yearly servicing and replacement of annodes
300 hours is fresh only

[billfisher]

Avoiding MerCruiser Bravo 3 Outdrive Corrosion Problems on Boats | My Boat Life (https://www.myboatlife.com/2013/03/avoiding-mercruiser-bravo-3-outdrive.html)

This link is pointing to corrosion on the leg adjacent to the propeller which is where you would expect it. Ie nothing about powerheads. Also it referred to moored boats. You need an electrolyte like saltwater for galvanic corrosion to occur. Isn't yours a trailer boat?

[bluefin59]

Sorry to hear of this happening it’s pretty crap really it certainly adds another reason not to touch these motors IMO ,is it a known problem on American boats surely if it was a regular problem there would be some info on The Hull Truth forum. Matt

[tunaticer]

Ok, which anodes are you referring to?
Stainless props will not cause powerhead corrosion....think about it.
The water intake is before the prop....the used water passes out through the various holes in the water jacket and exhaust channels.
At no point is water that goes through your motor in contact with the prop until it is discharged.

Stainless for the most part does not corrode because it is stable in salt water.

If the prop was the cause of your problem there would be visible marks on the prop.

Your mechanic spewed bullshit in your direction and you sopped it up plain and simple.

[catshark]

could be as simple as it never ever had anodes in it , dealer forgot to install them , someone else forgot to put them in , and boom your dealer is a physic called it before he saw it , think you got taken to the cleaners big time friend sorry about that it happens
S/S prop theory rubbish

[scottar]

I have solved my problem. I have an aluminium propeller. You can take your chances, Not my problem.
My anodes were corroding nicely thanks.
The 400 hours were only the hours the engine was running the time fishing at anchor could be 4 times that lets say 1,600 hours with hot or warm seawater in the power head.
Same as being moored for 2 months in seawater.
Anodes cannot protect against corrosion caused by stainless just look a the electron flow.
Feel free to use stainless propellers.
If I sold outboards I would recommend them.
Anyone else be warned your anodes won't protect you.


Hard to see corrosion in the power head. You should try.
If people want to take the risk of using a Stainless prop good for them.
My new motor is much more refined than the Etec.
Since 1970 I have worked with outboards, inboards, jet boats and a hover craft and never seen corrosion like this.
Of course the only one with massive corrosion happens to have a stainless prop.
Huge coincidence that Zinc anodes don't protect against Stainless then?


The seawater in the powerhead is hot and the water flow would keep the surface fresh for more corrosion.
My dealer had nothing to gain.
He predicted the corrosion before we pulled the powerhead off. Previous experience?
The corrosion was massive and the anodes were only mildly corroded.
We were going to patch the water jacket but the engine mounts were beyond patching and had already cracked.
I don't have a problem with stainless props as I no longer own one and never will.

Few points - Evinrude anodes have apparently been pure aluminium since 1990.

Your powerhead drains when sitting fishing so any "galvanic" corrosion had to occur in the 400 running hours.

The two engines I have had personal experience with that suffered water jacket corrosion were both running aluminium props.

Not sure who told you zinc doesn't protect against stainless but I think they are wrong otherwise every aluminium shaft driven vessel that is permanently moored would be on the bottom. The only metal I know of more reactive than zinc that is sometimes used is magnesium but it's only ever used in fresh water. Remember the aluminium in your engine isn't pure - it's an alloy. It's all in a Galvanic table.

Evinrude engine mounts do seem to have an issue. This problem was around before BRP took on evinrude though. Personally I think they simply hold salt against the alloy which causes the corrosion to kick off. I had similar issues with plastic fittings that allowed water to get trapped - essentially setting up crevice corrosion on rail mounts for rod holders on my last tin rig.

Did you run a flush additive? My old boy was fanatical with flushing his engine - and it was one of the two I have seen fail with alloy props. Holes from two cylinders through to the water jacket. In my experience, fresh water alone simply does not remove all the salt - even more so when potentially it is baked on after a hot engine is shut down. Even after flushing and a comprehensive wash and while stored in a shed I have seen my personal boats and engines "make water" as residual salt pulled moisture from the air in wet weather. Left sitting this will set up a corrosion pit which is near on impossible to then stop in my experience. The longer it sits out of use, the quicker it happens. With Dad's it could be attributed to a two year break courtesy of a serious back injury where the motor sat without being run. The addition of a detergent additive ( I have used a non corrosive car wash run through the motor for years and have recently started with SX50) definitely seems to make a difference.

Don't drop the ball on keeping an eye on internal corrosion simply because you have gone back to an alloy prop. It's been killing outboards of all brands for years regardless of propeller choice and will continue to do so.

[Bobpen]

Mercruisers come standard with Stainless propellers and factory fitted electronic corrosion control.
I think that says it all don't you?
Avoiding MerCruiser Bravo 3 Outdrive Corrosion Problems on Boats | My Boat Life (https://www.myboatlife.com/2013/03/avoiding-mercruiser-bravo-3-outdrive.html)

[billfisher]

Mercruisers come standard with Stainless propellers and factory fitted electronic corrosion control.
I think that says it all don't you?
Avoiding MerCruiser Bravo 3 Outdrive Corrosion Problems on Boats | My Boat Life (https://www.myboatlife.com/2013/03/avoiding-mercruiser-bravo-3-outdrive.html)

You put that up before - perhaps you didn't see my comments: This link is pointing to corrosion on the leg adjacent to the propeller which is where you would expect it. Ie nothing about powerheads. Also it referred to moored boats. You need an electrolyte like saltwater for galvanic corrosion to occur. Isn't yours a trailer boat?

[Lovey80]

I find it extremely odd that anyone could come to the conclusion that a stainless propeller mounted to a stainless propeller shaft could cause corrosion to the head/block of an outboard. It’s more likely that an aluminium propeller mounted to a stainless propeller shaft will corrode than than the prop causing engine corrosion. If that was the case, why would outboard manufacturers use stainless propeller shafts?

[CT]

Evinrude engine mounts do seem to have an issue. This problem was around before BRP took on evinrude though. Personally I think they simply hold salt against the alloy which causes the corrosion to kick off. I had similar issues with plastic fittings that allowed water to get trapped - essentially setting up crevice corrosion on rail mounts for rod holders on my last tin rig.



Totally agree with this. My 90 corroded out the mounts, but a new inner and outer exhaust housing plus mounts and I was away again.

[CT]

The corrosion was only in the power head. The outside of the motor was immaculate.


!3 years old. Looked immaculate until engine mounts failed.
Yearly leg oil change turned to $16,000 new engine.

So were the mounts corroded or the exhaust housing or the powerhead?

[Bobpen]

I think the corrosion occurred during the 1,600 hours I was using the boat either running or anchored in salt water and the power head was full of hot or warm salt water.

[Bobpen]

Look up galvanic corrosion before you post again.
Stainless is stronger.

[shortthenlong]

Was it 1600 or 400 hours?

Just for clarity cause #### this thread could use some.

Matt

[Bobpen]

The anodes were lightly corroded. What is your point. The looked liked they were doing something obviously not enough then.
Do you think Stainless propellers don't cause corrosion?
It is blindingly obvious that stainless props cause galvanic corrosion just look at the MerCruiser Post and why they factory fit electronic protection.
The last 4 services were by dealers.
My post was intended to warn owners of stainless props, How are you helping?
Avoiding MerCruiser Bravo 3 Outdrive Corrosion Problems on Boats | My Boat Life (https://www.myboatlife.com/2013/03/avoiding-mercruiser-bravo-3-outdrive.html)

[Bobpen]

The engine hours were 400 but I turn it off when I am anchored for some reason.
The boat was floating in seawater for 1,600 hours or so. Clear enough?
Hot or warm seawater in the power head for 1,600 hours.

[Bobpen]

Was it 1600 or 400 hours?

Just for clarity cause #### this thread could use some.

Matt
The engine hours were 400 but I turn it off when I am anchored for some reason.
The boat was floating in seawater for 1,600 hours or so. Clear enough?
Hot or warm seawater in the power head for 1,600 hours.

[tunaticer]

Which anodes are you referring to?
The ones on the leg or the ones inside the powerhead?

My bet is the ones in the powerhead have never been replaced.

[Bobpen]

Ok, which anodes are you referring to?
Stainless props will not cause powerhead corrosion....think about it.
The water intake is before the prop....the used water passes out through the various holes in the water jacket and exhaust channels.
At no point is water that goes through your motor in contact with the prop until it is discharged.

Stainless for the most part does not corrode because it is stable in salt water.

If the prop was the cause of your problem there would be visible marks on the prop.

Your mechanic spewed bullshit in your direction and you sopped it up plain and simple.

My mechanic called the corrosion problem before he took the head off.
He sees a lot of motors.
He just said I didn't flush it enough and tried to sell be a stainless prop for my new motor
Look up galvanic corrosion before you post again.
Stainless is protected by the Aluminium in the motor. The Aluminium casting of motor is one big Anode.
The same way the Aluminium in the motor is protected by the Zinc or Magnesium Anodes.

[stevej]

Is it blindingly obvious to you tens of thousands hundreds of thousands of people don’t have issues with stainless props
and if you Google it you find next to no examples of your issue

if your annodes wernt breaking down from use then something was not causing them to do their job

people have put more running hours on their engines than you have just floating there with no issues
what did brp say when you asked the manufacturer about your perceived negligence of them fitting a stainless prop

several brands have known issues of water galleries blocking up but a reputable dealer will know when to pull the covers off and clean it out

[Lovey80]

There’s no doubt corrosion caused your issue. There is a lot of doubt about your hypothesis that a stainless prop caused it. I recently had a blockage in my 2008 Suzuki. That engine had been bought new and religiously flushed. Actually half it’s hours were probably spent on the muffs at home. Yet the water jackets were full of salt crystals, sand and other deposits. After flushing vinegar through it I was shocked to see what was left in the bottom of the bin.

Just because you did the right thing as far as user maintenance, had it dealer serviced and still got corrosion in a 13 year old motor doesn’t make it any more likely that the prop was the cause. Especially considering you have a stainless prop shaft and other stainless parts in the engine that are far closer to the head/block than the prop is.

Yes galvanic corrosion could have played a part. But far more likely is that salt deposits built up in a crevice or against an impurity in the casting and did its work whilst it was out of the water than the prop turning your block into a massive anode. Especially considering the anodes on the block weren’t showing signs of severe corrosion over the years that should have raised an alarm if it was an acute galvanic corrosion event.

Considering others are saying the same engine has known issues of corrosion in the same place, that also leads to a more likely reason.

[Dignity]

Dr Google, Professor Google, HRH Google, Really, so much mis info there. I changed mechanics several times due to them giving me info that when deep research showed they were spouting garbage. One mechanic I thought was great wasn't, that was when I changed my domicile and had to get another one after most of my wiring had burnt off most of the insulation. Turns out there were several changes the Merc had issued as major updates for several years that just didn't happen, result as described.
The last time I looked at a prop either SS or Ally, there was a rubber bush between the prop itself and the splined hub that went onto the SS spline coming out of the motor gear box, I'm pretty sure mine there is some bronze in that bit maybe something else but I'm in agreement with the majority, your mechanic is spouting something that is not kosher.

Edit: Corrosion is rampant in lots of motors for many reasons, be aware of anyone that can point the finger before doing a proper diagnoses, I'd even change doctors on that basis.

[tunaticer]

Ok Bobpen....which ####ing anodes are you referring to?
I know fully well what galvanic corrosion is....
You have stainless steel in your water pump for starters as well as dozens of other places in your engine.

You either never had the powerhead anodes service / replaced or you were lacking basic engine flushing procedures.

Was your corrosion galvanic or just alloy decay???

Get you head around that.

[scottar]

QUOTE=Bobpen;1686681]My mechanic called the corrosion problem before he took the head off.
He sees a lot of motors.
He just said I didn't flush it enough and tried to sell be a stainless prop for my new motor
Look up galvanic corrosion before you post again.
Stainless is protected by the Aluminium in the motor. The Aluminium casting of motor is one big Anode.
The same way the Aluminium in the motor is protected by the Zinc or Magnesium Anodes.

[/QUOTE]

Which is it Bob - Galvanic or didn't flush it enough. If indeed your dealer did tell you that it simply wasn't flushed enough - I agree with him. It's also critical to outboards that they be run regularly - even if it's just at home on the hose during long periods of down time. This is when the most damage is done in a low hour motor

As a marine maintenance employee, I am pretty familiar with galvanic corrosion. If indeed your theory held water, please explain why permanently moored aluminium vessels - fitted with anodes to protect them, simply don't dissolve around their own stainless steel drive shafts and bronze propellers - not to mention your theory behind engines with aluminium props that this happens to as well. I would suggest you do a bit more research on just how anodes work. The reason your anodes were only lightly corroded - they only did 400 hours - a grand total of about 17 days actual work. Even if it was 1600 hours - do you really think a motor with a stainless propeller - fitted with anodes for protection - is going to be in the same condition as your old E-Tec in just over two months if left sitting in the water 24-7. Hundreds of thousands (probably millions) of outdrives and ouboards around the globe would tend to indicate no. The math simply does not add up. Corrosion due to residual salt, moisture and air however - goes 24-7 and will do all sorts of damage over a few years.



The engine hours were 400 but I turn it off when I am anchored for some reason.
The boat was floating in seawater for 1,600 hours or so. Clear enough?
Hot or warm seawater in the power head for 1,600 hours.

Again. When the engine is shut down, the powerhead drains. The telltale outlet means the system is not sealed and gravity takes care of the rest. There is literally no connection via water to allow galvanic corrosion within the engine itself without the engine running. However - there is most definitely salt being baked onto the metal by residual engine heat that fresh water flushing alone will not remove.

[scottar]

[QUOTE=tunaticer;1686691
You either never had the powerhead anodes service / replaced or you were lacking basic engine flushing procedures.
[/QUOTE]

Not sure Evinrude has ever run internal anodes in the powerhead. Once the water leaves the leg, there is no other metal besides aluminium it comes into contact with. There have only ever been anodes in front of the prop, on the transom bracket and above the steering torque tab or the tab itself on any of the OMC/BRP motors I've had anything to do with.

[Lovey80]

They don’t have anodes in the block like Yamaha/Suzuki do?

[scottar]

They don’t have anodes in the block like Yamaha/Suzuki do?

Not any of the motors I have ever owned or had to work on. OMC always had pretty good metallurgy. From memory there was a big court case against Yamaha for copying their alloy at one stage way back.

[gazza2006au]

Bopen your going to need wadders when u put the new engine in salt water not because the nippers will bite you're toes but your pearly whites will erode due to the fizzyness from standing in salt water :) only playing

I would get someone to look over the boat especially if someone has earthed a negative to the hull for the return power wires

[tunaticer]

Not sure Evinrude has ever run internal anodes in the powerhead. Once the water leaves the leg, there is no other metal besides aluminium it comes into contact with. There have only ever been anodes in front of the prop, on the transom bracket and above the steering torque tab or the tab itself on any of the OMC/BRP motors I've had anything to do with.
My evinrude had two in the powerhead....

[scottar]

My evinrude had two in the powerhead....

There you go. What model just in case I ever come across one?

[Bobpen]

I think my stainless propeller may have caused catastrophic corrosion in the power head of my 90 Etec after 400 hours.
Can anyone confirm this???
It cost me $16,000 to replace the whole motor.

Perhaps tilting the motor so the prop and leg was out of the water for the 1,200 hours the boat was anchored might have helped.

[Lovey80]

Nope. Tilting your engine wouldn’t have removed the salt in the power head that built up over 13 years.