Flushing engine after use on salt water-boat kept at slip

P

pbblair

New Member
Sep 4, 2007
4
Massachusetts
Boat Info
200 Sundeck
Engines
235 Mercruiser
I keep my boat at a slip in salt water. Do I need to flush the engine with clean water after use and if so how ? It is in I/O Mercruiser 4.3L MPI Alpha, 220 HP, gas engine.
Thanks.
 
The I/O is not designed for storage in salt water. It's ok for a while, but not very long. I have a buddy that had his in salt for 5 months, and when he traded it in, they said he was very close to a $5,000 bill for the two I/O's.

There are after-market rinse kits which can be installed to fresh-water rinse your engine while in salt water. They're not cheap, but they do exist. I think they're about $500 per side.
 
The rinse system typically consist of an in-line hose bib connected to the water pump in the bilge.
 
Since you have an Alpha, there is a water pump in the lower unit. This will rule out some options like the Perko Flush Pro (which I have in my B3 and works nicely).

Your best option is to dry rack the boat or find a slip with a lift. Like the previous post said, I/Os and salt water don't mix well together.

There are other flushing options (MST Guardian and similar, NeutraSalt, others), but a key concern will remain your outdrive in salt water.

Esteban
 
Boat Kept In Salt Water Wet Slip

Sounds like you are keeping the boat in a salt water wet slip and the boat is not fresh water cooler? IE No self contained cooling system with antifreeze in it.

If so-there are some general considerations besides flushing the engine. You may also want to consider adding zincs to other areas of the outdrive/boat than normally provided and check them a couple of times a year. You may want to paint the bottom of the boat & outdrive to help avoid the growth of algae or barnicles. Even with bottom paint, consider having the bottom cleaned by a diver, which is determined by the general rate of growth at your marina. Asking others around you for advice will help make your salt water wet slip experience better.

Kevin
1991 250/270 Weekender, 454, 330 HP, Bravo II
 
Hi pbblair,

I have been told that it is of very little benefit to flush an engine kept in salt water. (or ... It's ok not to flush it)
I have a 260DA with a BIII drive that we keep in a salt water slip. This is our first year with the boat and I was very high to have a flush system installed but none of the pros recommended it. The dealer was supposed to install a flush port before I picked up the boat. First they tried to talk me out of it then they just didn't do it and used the "we forgot" excuse when they delivered the boat. They all said it would be more trouble than it is worth. Here's some of what I was told:
1. As long as you keep the boat in the water the engine and drive stay full of water and the salt stays in solution so it won't collect in the engine. Just flush with a salt-disolving solution when you take it out of the water.
2. Even if you flush with fresh water the salt water will enter the engine anyway (fogot the technical term) and the engine will be filled with salt water after a few hours.
3. Adding valves and shutoffs to your cooling system could put stress on other components like the impeller.
4. You add the possibility that you will forget to open a valve and cause engine or cooling system damage.

The only place where I saw a strong case for flushing was on the websites that sell the flush systems.

After spending a year trying to get someone to install a flushing system I am giving up. I'm just going to enjoy the boat and take the consequences.

Good luck,
Charlie
 
I have a perko flush system on my engines and it's really quite easy to use. hook up a hose, open the engine drain and turn it on. Not sure how salt water can work it's way back into the engine as it needs to be pumped in.
 
Charlie,

I really like your solution. I hope you're right. You would think that on gas powered inboards Sea Ray would build them with a system or at least offer a system if it was a requirement. Of course, they want service business, but not at the cost of their reputation. What are the other companies doing for salt water boats designed to stay in the water?

My local SR service shop recommends installing a rinse system to "Protect your investment," but they don't really have a plan on how to do it. There is no set standard. I think they must make more money on the systems than on the repairs.

My 340 has been in salt for 3 years. I'm having the exhaust pulled this winter - we'll see how we're doing. I bet I need new exhaust parts, but for driving up to the dock, tying it off, and walking away for 3 1/2 years, it's probably well worth it.
 
TurtleTone said:
Not sure how salt water can work it's way back into the engine as it needs to be pumped in.
Click to expand...

This is Chemistry 101 .. it's a physical property of liquid solutions like salt water called "Osmotic Pressure". This is the property where a pure solvent (e.g. fresh water) naturally tries to mix with the solution (e.g. salt water).

The Perko valve made me nervous because it's plastic and would be in the raw water intake line below the water line. (I guess I could have plumbed it up above the water line) I was strongly considering installing a Perko valve myself before I gave up on the whole idea.

-C
 
I failed chemistry 101...... But I rocked woodshop.

My valve is mounted above the waterline. Works great and it's going on 5 years now. I'm thinking of swapping in some new valves this winter (just in case) not sure what the life expectancy is on these things.
 
I have the Perko Flush Pro since June (I know, not too long), but so far it has worked nicely.

I keep my boat on a dry rack. When I leave the boat on the slip for the forklift, I connect a hose to the Flush Pro remote inlet in the transom locker and run Salt Terminator through it with the garden hose until I see "soapy bubbles" coming from the exhaust in the outdrive.

The FlushPro is under $100, easy to install, and Salt Terminator is relatively inexpensive as well.

I'm not expecting this setup to make my RWC salt water engine behave like it's FWC, but I think/hope it does help somewhat to keep the engine in better condition.

The flushing system that you run with the engine off (backfill) is the one I have heard that can cause problems with water getting into the engine. This, and the higher cost is what made me go with the FlushPro.

Esteban
 
charlieft said:
Hi pbblair,

I have been told that it is of very little benefit to flush an engine kept in salt water. (or ... It's ok not to flush it)
I have a 260DA with a BIII drive that we keep in a salt water slip. This is our first year with the boat and I was very high to have a flush system installed but none of the pros recommended it. The dealer was supposed to install a flush port before I picked up the boat. First they tried to talk me out of it then they just didn't do it and used the "we forgot" excuse when they delivered the boat. They all said it would be more trouble than it is worth. Here's some of what I was told:
1. As long as you keep the boat in the water the engine and drive stay full of water and the salt stays in solution so it won't collect in the engine. Just flush with a salt-disolving solution when you take it out of the water.
2. Even if you flush with fresh water the salt water will enter the engine anyway (fogot the technical term) and the engine will be filled with salt water after a few hours.
3. Adding valves and shutoffs to your cooling system could put stress on other components like the impeller.
4. You add the possibility that you will forget to open a valve and cause engine or cooling system damage.

The only place where I saw a strong case for flushing was on the websites that sell the flush systems.

After spending a year trying to get someone to install a flushing system I am giving up. I'm just going to enjoy the boat and take the consequences.

Good luck,
Charlie
Click to expand...
I'm curious about this also. I have a 2015 Sundancer which is stored in salt water and regular flushing doesn't seem feasible without water intake seacocks. Comments from any others?
 
He has an alpha. So water is through the drive. Can't just put a flush kit on it. I flush mine after every use with salt away
 
350MattR1 said:
I'm curious about this also. I have a 2015 Sundancer which is stored in salt water and regular flushing doesn't seem feasible without water intake seacocks. Comments from any others?
Click to expand...
What drive setup do you have?
 
Thanks - I have Mercury Bravo IIIs (sterndrives)
 
350MattR1 said:
Thanks - I have Mercury Bravo IIIs (sterndrives)
Click to expand...
So, yeah, reaching down and putting a flush muff on each drive is not too convenient :)

BUT... you could install a bronze T into the intake hose before the sea water pump... use a 1-1/4"x3/4"x1-1/4". Use water/exhaust rated hose and run a length to convenient spot where you can install a shutoff valve. Then continue the run to where you install a hose end fitting. Now, attach the flush hose and open the valve and start the engine. Yes, some salt water will still be sucked in - but most of the water going through your system will be fresh.

FYI, don't use the "Perko" system - it can get clogged and/or the spring can get stuck.

NOTE: The person you originally quoted asked about flushing an "engine"... you obviously don't need to worry about the actual engine.
 
Thanks Lazy Daze. Yes, to be more precise - just the raw water section of the cooling system
 
Sorry I did not see that
 
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