How much corrosion is normal?

[jakew009]

Looking at buying a boat with a 2005 Verado 250 with 500 hours.

The engine looks in reasonable condition overall, but there is what looks to me like a lot of corrosion on the lower unit. Is this normal and how worried should I be?

Photos below, click to make bigger

Thanks

[boristhebold]

I would not buy it. That much corrosion which has obviously been painted over is way too much, the point of having anodes on the engine is to prevent corrosion, looks to me like the boat has been in the water for alot of time and perhaps the owner didnt keep up with regularly changing the anodes.

You would expect some paint to rub off from the lower leg which is normal over a long time and would just need a respray but for the actual metal of the lower leg to be like that, well ive never seen any like that.

Just look round a marina, look on the dry stack and compare and look at boats on moorings and compare. 500 hours on an engine from 2005 seems very low use to me, thats 33 hours a year use average which is 2.75 hours a month on average. Should not look like that unless the anodes have not been changed and its sat in salt water for a long time.

Walk away.

[xpertski]

Agree with the above - looks like corrosion has been peeled off, flakes removed then painted without filling in the corrosion - probably tidied up (poorly and quickly) for sale. Reality is that this shouldn’t happen with looking after the anodes but probably wasn’t inspected for a while. Proper job would have tried to fill the corrosion, sand level and repaint properly. I would think there are better engines out there - probably left on a boat with the lower leg left in the water. Saying that if the mechanics have been looked after and serviced with evidence it might be the excuse for a really cheap deal - but suppose would depend if you are happy with the level of corrosion damage and whether that neglect is symptomatic of neglect in the maintenance of the rest of the engine ....

[xpertski]

Only comment on the hours from Boris is that I don’t think 500 hours is too low in itself for a seasonally used engine- we had a Suzuki 140 with less hours and 2004 year which was looked after (servicing, anodes etc) but used only each summer for odd weekends and a casual boating week here or there. Agree with him re condition though

[Fender]

Originally Posted by boristhebold

I would not buy it. That much corrosion which has obviously been painted over is way too much, the point of having anodes on the engine is to prevent corrosion, looks to me like the boat has been in the water for alot of time and perhaps the owner didnt keep up with regularly changing the anodes.

You would expect some paint to rub off from the lower leg which is normal over a long time and would just need a respray but for the actual metal of the lower leg to be like that, well ive never seen any like that.

Just look round a marina, look on the dry stack and compare and look at boats on moorings and compare. 500 hours on an engine from 2005 seems very low use to me, thats 33 hours a year use average which is 2.75 hours a month on average. Should not look like that unless the anodes have not been changed and its sat in salt water for a long time.

Walk away.

33 hours per season isn't unheard of, think average hours for a leisure boat is 50? Some my way NEVER seem to move!!

[spartacus]

Looks like the boat has been sitting in the marina with the leg down. The boat, what's it like? If it's been antifouled, then you know the sort of life its had. Again, the tubes and deck furniture will reveal a lot. Don't write off the engine completely if the boat is mint, but I'd be factoring in a new lower unit in any negotiation. I'd also want to look at the cylinders, do a compression test and check thermostat housing to see if it's been flushed regularly.

[Fender]

Originally Posted by spartacus

Looks like the boat has been sitting in the marina with the leg down. The boat, what's it like? If it's been antifouled, then you know the sort of life its had. Again, the tubes and deck furniture will reveal a lot. Don't write off the engine completely if the boat is mint, but I'd be factoring in a new lower unit in any negotiation. I'd also want to look at the cylinders, do a compression test and check thermostat housing to see if it's been flushed regularly.

And poss Electrolytic Corrosion?

[jeffstevens763@g]

Originally Posted by Fender

And poss Electrolytic Corrosion?

yep stray current from a power source unless it was left with the anodes depleted

[spartacus]

Originally Posted by Fender

And poss Electrolytic Corrosion?

Possibly. Not sure how many sacrificial anodes the engine has, and have all been replaced? Closer inspection of head will reveal a lot.

[Ribtecer]

Originally Posted by boristhebold

Walk away.

I wouldn't walk away, I'd run away very quickly. I like a project, but that has been abused.

Buyer's market out there.

Unless as has been said, you get the engine for nearly nothing.

Is that on the Cobra Rib?

[Last Tango]

Or......

The original gearbox has been pranged and someone's manage to pick up another one cheep off Fleabay..

The top of front of the "torpedo" looks like it's been filled or welded up as well.

[Locozodiac]

Aside from changing anodes when they have been excessively eroded, the new ones should be well maintained, that's brushed periodically with a Dremel rotating powered tool and a small circular metal brush as to keep them immaculate clean and doing their homework right. Will last much longer than just replacing them...

Happy Boating

[Searider]

That lower unit I wouldn't want to rely on.
It's been tarted up by the seller to make it look pretty.
If something as visible as this has been neglected what else has also been neglected.

A Verado is a very complex engine with plenty to go wrong if not cared for.

Only worth considering if it's VERY cheap.

[spartacus]

As far as I can see there 8 anodes on this engine, 5 alone on the trim assembly. These are useful reference guides for the parts. https://www.boats.net/catalog/mercur...rd-by-hp/250hp

[Blankton]

Interesting photos, from a metallurgical point of view.

The housing next to the prop has suffered galvanic attack being next to the stainless prop. There is also a lot of attack right next to some of the annodes.
It looks like it must have been left in the water and the annodes were totally consumed. After zinc has gone, aluminium is next galvanically.

It's a bit poor that someone has bodged it up, I'd guess by a light blast to remove loose debris and re-painting.

Has enough of the casings been lost to make them structurally unsound - maybe not. But note how the corrosion has gone in crevice locations, so features like o ring grooves, which you can't see, might have been badly affected.

Also, if someone 'forgot' about the engine in the water for a couple of years, the chances are that it wasn't winterised properly and there could be pitting of cylinder bores etc.

If what you can see is as bad as it gets, then there might be a bargain to be had. But really you'd want to strip it down to check the internal condition.

[Nos4r2]

Originally Posted by spartacus

As far as I can see there 8 anodes on this engine, 5 alone on the trim assembly. These are useful reference guides for the parts. https://www.boats.net/catalog/mercur...rd-by-hp/250hp

Nothing internal? I'd be surprised if there's no anodes in the waterways.


That's actually what my Yam 85's anodes looked like after being in the water somewhere with earth leakage issues. I'd stay clear.
My '02 225 Opti with nearly 1000 hours on, which was used commercially as well had nowhere near that level of pitting when i sold it last year.

[jakew009]

Thanks for all the replies.

Still mulling this one over in my head.

I’ve now got a lot of service history for the boat, almost every service since the boat was new.

What appears to have happened, backed up by paperwork, is that the boat had a problem with the tilt / trim unit starting September 2018. The boat was sat on a versadock.

It appears that from September 2018 - Feb 2019 the engine was sat in the water and this is when the corrosion happened. Quite how the corrosion happened so badly is unexplained, but the only possible reason I can see is that there was some sort of stray electrical current around.

On the basis that the factory electrics looks pretty home brew on the boat, I’m starting to wonder if the current may have come from the boat itself somehow? How else could such a large amount of happened in such a short period of time?

The anodes are as far as I can see from the paperwork have been on the boat since 2009. The anodes haven’t been changed subsequent to the ‘corrosion incident’.

So my main question is why wouldn’t the anodes have protected the engine?

My second question is would some sort of electrical issue on the boat itself cause this sort of rapid galvanic corrosion? I’m thinking the trim issue must have been electrical as they never found a mechanic cause of it.

I appreciate the calls to walk away, but a) somehow has to buy it, and b) there’s lots of 15/20 year old boats out there for sale with pretty worthless engines on them. At least I’m not going to be surprised if this one needs replacing ��

[jakew009]

Originally Posted by Nos4r2

That's actually what my Yam 85's anodes looked like after being in the water somewhere with earth leakage issues.

Are you able to give me a bit more details about what happened? Did multiple boats get affected? Why was your engine in the water?

[spartacus]

Originally Posted by jakew009

What appears to have happened, backed up by paperwork, is that the boat had a problem with the tilt / trim unit starting September 2018. The boat was sat on a versadock.

Hi Jake - has that fault subsequently been fixed? Faulty solenoid, trim motor failure, ATF fluid leak? I know you've said they never traced this to a mechanical issue?

It appears that from September 2018 - Feb 2019 the engine was sat in the water and this is when the corrosion happened. Quite how the corrosion happened so badly is unexplained, but the only possible reason I can see is that there was some sort of stray electrical current around.

So just 6 months. I agree the corrosion is bad. Sacrificial anodes work on the basis that they corrode first being a dissimilar or softer metal to the outboard. That said you just need a broken earth strap for corrosion to start. I think this is more advanced corrosion, and I'd be looking at a stray current. Could be as simple as fault at the bilge pump for example with chaffed or exposed wiring - and that will exacerbate the problem. Your point below confirms this. If it was on a versadock, was their shore power out of curiosity?

On the basis that the factory electrics looks pretty home brew on the boat, I’m starting to wonder if the current may have come from the boat itself somehow? How else could such a large amount of happened in such a short period of time?

The anodes are as far as I can see from the paperwork have been on the boat since 2009. The anodes haven’t been changed subsequent to the ‘corrosion incident’.

At the very least they should be removed, wire brushed to inspect corrosion, then re-seated. They are inexpensive to replace when you consider the value of the engine. There's 8 as a far as I can see on this engine, have you or the broker inspected them all?

So my main question is why wouldn’t the anodes have protected the engine?

If the leg has been in the water - then assuming this is stray current it's bypassing the anodes and earthing with the water.

My second question is would some sort of electrical issue on the boat itself cause this sort of rapid galvanic corrosion? I’m thinking the trim issue must have been electrical as they never found a mechanic cause of it.

Tracing electrical faults isn't for the faint-hearted. You've mentioned the electrics look home-brew. Rip the lot out and start again with tinned wiring, a battery isolator, fuse-box, etc. That way you know it's done right. Even the battery cables from battery to the engine - if they run under the deck which I assume they do, check the conduit, is it bone dry? An electrical multi-meter is an invaluable bit of kit when installing and testing.

I appreciate the calls to walk away, but a) somehow has to buy it, and b) there’s lots of 15/20 year old boats out there for sale with pretty worthless engines on them. At least I’m not going to be surprised if this one needs replacing

You're going into it with your eyes open. If it was me I'd want a look at the injectors (they can be spray pattern tested) and a visual inspection of the cylinders on this engine. The money you're saving - you can potentially budget for a second-hand leg down the line. I wouldn't part with my hard-earned cash unless I knew the block itself was solid. I'd also be inclined to drop the gear oil more often than an annual service to be sure it's watertight.

Anyway - best of luck whatever you decide.

This is an interesting video on all aspects of marine corrosion. Check that shirt!

https://www.youtube.com/watch?v=VSx2iEC1Hhk

[jakew009]

Originally Posted by spartacus

Hi Jake - has that fault subsequently been fixed? Faulty solenoid, trim motor failure, ATF fluid leak? I know you've said they never traced this to a mechanical issue?

Correct, I don’t believe this fault was ever fixed. The first time the dealer look at it they noticed the fluid level was low and topped it up. They then checked it 24 hours later and it had stayed up.

Second time they looked at it they couldn’t find fault either. The fact it stays up ok on the trailer again makes me suspect some sort of electrical issue causing it to lower 🥺

So just 6 months. I agree the corrosion is bad. Sacrificial anodes work on the basis that they corrode first being a dissimilar or softer metal to the outboard. That said you just need a broken earth strap for corrosion to start. I think this is more advanced corrosion, and I'd be looking at a stray current. Could be as simple as fault at the bilge pump for example with chaffed or exposed wiring - and that will exacerbate the problem. Your point below confirms this. If it was on a versadock, was their shore power out of curiosity?

I must admit I didn’t notice any earth straps on the engine, I assume they are just tying the different parts of the outboard together so at the same potential? I will have to look at a parts diagram.

At the very least they should be removed, wire brushed to inspect corrosion, then re-seated. They are inexpensive to replace when you consider the value of the engine. There's 8 as a far as I can see on this engine, have you or the broker inspected them all?

I know they are all present, and they don’t even look in that bad condition, which is why I don’t understand why they didn’t do their job properly!

If the leg has been in the water - then assuming this is stray current it's bypassing the anodes and earthing with the water.

Agree

Tracing electrical faults isn't for the faint-hearted. You've mentioned the electrics look home-brew. Rip the lot out and start again with tinned wiring, a battery isolator, fuse-box, etc. That way you know it's done right. Even the battery cables from battery to the engine - if they run under the deck which I assume they do, check the conduit, is it bone dry? An electrical multi-meter is an invaluable bit of kit when installing and testing.

That’s my plan, desiring it doesn’t phase me at all. It was my plan anyway with whatever boat I bought. My Fluke meters may make an appearance

You're going into it with your eyes open. If it was me I'd want a look at the injectors (they can be spray pattern tested) and a visual inspection of the cylinders on this engine. The money you're saving - you can potentially budget for a second-hand leg down the line. I wouldn't part with my hard-earned cash unless I knew the block itself was solid. I'd also be inclined to drop the gear oil more often than an annual service to be sure it's watertight.

I’m pretty much budgeting for a complete second hand engine at this point. I can import an identical engine from the States for 4k or so. At that point I will have two engines and will be able to easily swap parts / complete engine as necessary.

Looking at prices of secondhand engines, early 2000 2 strokes are pretty much worthless now (old optimaxes, yam hpdis etc), and there’s plenty of ribs with said engines hung on the back for sale. Therefore that gives me a fairly good idea what the hull value is.