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Old 11 September 2008, 14:52   #1
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Lower Leg Aids ?

Hello

This engine used in salt water has been experimenting some strange problems, looks as a surface primer base & paint corrossion and maybe has reached metal already. The engine is completely rinse with fresh water and water flushed with engine on for about 10 minutes. The corrossion is begining to appear at the tail lower ground nut and engine water indicator & exhaust water port.

All anodes are in good shape have been removed and sanded for a better contact, were found not full of salt and still making good contact, will remove cable grounding to have a look, maybe doing a poor electrical contact from engine body to lower leg.

Would appreciate any ideas, thoughts about this kind of problem and what to do ?

Happy Boating
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Old 12 September 2008, 04:47   #2
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Well, I'd say it's definitely surface corrosion under the paint, but I couldn't tell you what's causing it. Sounds to me like you're doing everything right.

jky
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Old 12 September 2008, 09:25   #3
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Well, I'd say it's definitely surface corrosion under the paint, but I couldn't tell you what's causing it. Sounds to me like you're doing everything right.

jky
Thanks JKY, will remove engine lower leg ground cables and have a look, sand them and see if the corrosion continues, would you advise to sand the 2 problem parts, base primer and repaint ?
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Old 12 September 2008, 12:47   #4
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Have removed all ground cables and bolts, bolt threads were a little fouled with salt, have cleaned with thinner all bolst & engine bolts threads, greased well threads, adjusted bolts back, will see if the corrosion continues or stops there.
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Old 12 September 2008, 15:44   #5
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weight of anodes

Locozodiac

Be not decieved by the surface of the anodes. I am told the big thing is the weight of the anodes. Sometimes they look all right but will have shed a lot of their weight and are effectively useless. If in doubt replace.

Have you had someone check for leakage of corrent from your electrical system?

Best of luck.
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Old 14 September 2008, 10:24   #6
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Locozodiac

Be not decieved by the surface of the anodes. I am told the big thing is the weight of the anodes. Sometimes they look all right but will have shed a lot of their weight and are effectively useless. If in doubt replace.

Have you had someone check for leakage of corrent from your electrical system?

Best of luck.
Ez, Anodes are perfect, no difference with new ones, not even hard corroded, just slight normal wear that look like brand new after the sanding work to justify a change.

Is there a method to check/look for this current leakage, the engine is performing at it's best at all throttle range. Will see if after the anodes and ground clean up, the corrosion continues. Thanks
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Old 16 September 2008, 15:25   #7
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Hello
I Am new to the forum but not new to boats.
I live in portugal and work at a cobalt/jeaunau powerboats importer, and I see this tipe of problem every day especialy on inboards and sterndrives.

I have found this problem quite often with outboards( especialy with older suzuki's)
Check if you have alot of stainless parts in the water near the engine, Weaker metal erode much quiker, check to see if you have the correct anoedes recomended by the manufacture. There are 3 types.
The other problem is bad aluminum and bad painting/plating process.

I now you can take measuments of the electrical current around the boat to check for bad continuaty or possible current loss or excess or current. Have done it several times on Mercruiser drive units.

Cumps Fernando
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Old 16 September 2008, 17:12   #8
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Hello
I Am new to the forum but not new to boats.
I live in portugal and work at a cobalt/jeaunau powerboats importer, and I see this tipe of problem every day especialy on inboards and sterndrives.

I have found this problem quite often with outboards( especialy with older suzuki's)
Check if you have alot of stainless parts in the water near the engine, Weaker metal erode much quiker, check to see if you have the correct anoedes recomended by the manufacture. There are 3 types.
The other problem is bad aluminum and bad painting/plating process.

I now you can take measuments of the electrical current around the boat to check for bad continuaty or possible current loss or excess or current. Have done it several times on Mercruiser drive units.

Cumps Fernando
Thanks Fernando for the imput, a relief to read that this is kind of "comon/normal" issue to happen to outboards & stern drives, in my case all 3 anodes are factory originals with just 1 constant year engine use, prob a bad quality plating/painting on that area. Will sand, prime and repaint that area.

Is there a way to check current loss or too much of it, please advise method to check.

Happy Boating
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Old 16 September 2008, 19:01   #9
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Thanks Fernando for the imput, a relief to read that this is kind of "comon/normal" issue to happen to outboards & stern drives, in my case all 3 anodes are factory originals with just 1 constant year engine use, prob a bad quality plating/painting on that area. Will sand, prime and repaint that area.

Is there a way to check current loss or too much of it, please advise method to check.

Happy Boating
It´s not normal to happen, the aluminum will just rot away or get pourous!!! Be carefull and try to treat and find the cause,

What is happening is this
http://en.wikipedia.org/wiki/Galvanic_corrosion

Dont now if it is possible to read any galvanic currentwith a small outboard
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