Salt water

Discussion in 'Outboards' started by Manie B, Jul 3, 2011.

  1. Manie B
    Joined: Sep 2006
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    Manie B Senior Member

    Gents anybody got any idea on how long a 12v Minnkota 30 lbs thrust will last in salt water
    the manufacture states not suitable for salt water but I am hoping with occasional use and regular flushing it could be reasonably ok
    I am not expecting miracles but anybody ever tried?

    Next question
    small 5 hp fourstroke Parson outboard (Yamaha copy) in salt water
    any idea how long the water pump impellor will last with REGULAR sea water usage
    in this case it will be extremely difficult to flush with fresh water
    so basically I know the motor will rust to pieces from the inside
    could I get 2 years ?? at say 1000 hours total = 42 hours per month ??
     

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  2. Submarine Tom

    Submarine Tom Previous Member

    I think if you rinsed it and then left it sitting in fresh water for 24 hours you'd be okay.

    But, only time will tell...

    -Tom
     
  3. hoytedow
    Joined: Sep 2009
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    hoytedow Carbon Based Life Form

    Lay on zinc to help with corrosion.
     

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    Last edited: Jul 5, 2011
  4. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    The minn kota I had was similar ....all I did was to remove the prop and oil the shaft where it goes into the motor ...a drop of engine seal that expands the oil seal is a good idea ...main thing is not to run it out of water as this wrecks the shaft seal...note the small 12v minn kota run real good on 24v
     
  5. CDK
    Joined: Aug 2007
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    CDK retired engineer

    There is of course a chemical reaction between exposed aluminum and seawater, but mainly when the engine is in use. The effects of seawater remaining in the engine are greatly exaggerated: the corrosion process slows down considerably when the temperature has dropped and once the available oxygen has been used, it stops completely until the next engine start.

    My 5 hp Mercury (Tohatsu) just celebrated its 20th year at sea, was never flushed and is still operational. But it looks terrible and is rarely used: 1000 engine hours is not what a small outboard was designed for.
     
  6. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    I have the same Minkota, I had it stowed in a dry compartment in my bay boat for a few trips in the salt, it was never in the water.

    It was about 6 months later when I found it and most of the black paint on the motor housing had fallen off due to corrosion on the aluminum.
     
  7. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    They use an alloy called Zamak.
    It is cheap and flows very well during the die cast process, but paint doesn't adhere to it unless an etching primer is used.

    http://en.wikipedia.org/wiki/Zamak
     
  8. Manie B
    Joined: Sep 2006
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    Location: Cape Town South Africa

    Manie B Senior Member

    thanks for the reply's

    any guess of how long??
    anybody out there that uses a small motor on a daily basis?
    I know this is like asking how long is a piece of string
    but any guide line will help

    this is VERY encouraging

    thanks
     
  9. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    If I were to design an outboard engine it should survive the warranty period plus some reserve. One year warranty means approx. 200 hours of private use, for commercially used engines 90 days is common.

    That doesn't mean the engine will fall apart after 200 hours, but it may need some maintenance like changing oil, plugs etc.
    A common problem with outboards at sea is that the stainless fasteners are very hard to remove after some time. Unscrewing them when new and smearing some Molykote on the thread can prevent that.
     
  10. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    Ahhhh......just got the 1949 Seagull out and found no corrosion ..started second pull and off we go ....( in truth I thik they are dangerous ..no FNR and all that spinning metal ..difficult in modern seaway .) Thats 60 years + if I calculate right ....
     

  11. hoytedow
    Joined: Sep 2009
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    hoytedow Carbon Based Life Form

    Older.
     
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