Saltwater vs. Freshwater

[medic4511]

I've been looking to upgrade my outboard. Recently I found two 90 hp mercs (90elpto) that were previously used in saltwater. One is a 1998 and the other a 1999. As a freshwater boater, what do I need to be concerned about when considering a used outboard that ran in saltwater. I vaguely understand that saltwater=corosion. I also know that new motors are available for specific saltwatrer use. I'm gonna get locked into winter shortly so is a saltwater outboard worth it (assuming all else is O.K.) or should I hold out for a Freshwater engine.

Thanks in advance for your advice and direction

SM

 

[Scaaty]

Re: Saltwater vs. Freshwater

It really depends how it was treated when in the salt. If it was trailered, and flushed when yanked out the water, not a problem. I dunk a 125hp OB in and leave it for up to 3 weeks , then its out for a flush (I use Saltaway) and watch the tiny barnacles die and get blown away with the P-Washer on the hull. 12 years on it (and its even a FORCE) with no problems. Depends on price too.
Hold on.. there will be more opposite opinions I'm sure

 

[MortenH]

Re: Saltwater vs. Freshwater

I agree - the treatment is most important. My Merc has run in salt water since 1984, always in a marine the summer season and flushed before winterizing, and I have not found any corrocorrosion. I have had her completely torn apart, inspected and rebuild. But with bad maintenance, it might be a problem. And I guess the temperature also have some influence. Here in Norway it is generally cold, and that slows the corrrosion down a bit. The bolts may be destroyed, there could be internal corrosion damage, external corrosion damage or the electrical system may be corroded into trash. You will get an idea about it with visual inspection of the overall condition. If everything looks clean and fresh on the outside, chances are good that the inside is good.

-M-

 

[tashasdaddy]

Re: Saltwater vs. Freshwater

i run my engine is fresh and salt, being in Florida. the after care is most important. the rinsing and flushing. i would not buy a saltwater run engine, without physically inspecting it first. the salt water models are suppose to have a coating or something lining the cooling system, but salt is salt, 3 weeks in the Keys and everything is cover in the salt deposits.

 

[Scaaty]

Re: Saltwater vs. Freshwater

Just thought of something...as it (they) need new impellers once in a while, see just how easy the lower bolts loosen up. It they don't turn, walk away...corroded bolts in the case will have you tearing your hair out

 

[Chris1956]

Re: Saltwater vs. Freshwater

SM, There are two major differences that salt water usage make to an outboard, which is not flushed every trip. The first is the ability to disassemble the motor to repair it. After a few years of use, on the salt water motors, the steel bolts that hold on the water jackets (inner and outer) tend to break upon removal. This usually doesn't happen on fresh water motors. It also doesn't happen too often on salt water motors with ss bolts, however, these kinds of motors are pretty rare.

The second issue is that salt water will rot out certain aluminum components of the motors. It is usually the parts that are water cooled. On the inline Mercs, it is the inner water jacket cover, the outer water jacket cover and the baffle plate. Fresh water motors don't have this constraint.

The good news is that the motors you are considering are not too old, so the parts are not likely to be rotted out, and once you put them into the fresh water, the rotting will cease. I would look over the motor block surface to see if their is any obvious corrosion or maintenance issues. It would be great to try to remove a few bolts, but if you were to break one, that would be bad.:^

 

[MortenH]

Re: Saltwater vs. Freshwater

Most of the bolts used are SS, but that is not always a good thing. SS is more brittle than conventional bolts, and therefore breaks easier. And after some years, the salt makes the bolts stick pretty hard. It is not the corrosion that makes them stick, but the salt. And if a SS bolt breaks, they are harder than conventional bolts, making them more difficult to remove.

-M-