Flushing outboard motor after each use

bh0526

New Member
Joined
12 Feb 2010
Messages
7
Visit site
Hi all,

I am new to boating as of a year ago. I have a 20' Sea Hunt Excape with a 150 HP Mercury outboard. I take out the boat about one every week or 2. The boat is in south Florida in saltwater. I have a private dock. I tilt the motor out of the water while docked.

I just found out that I should be flushing the motor after each use. I have not been doing this. Could I have seriously damaged the motor by not flushing? Is there anything I can do at this point?

Thanks,

Bob
 
Hello Bob

Welcome to the forum........The regular use your boat is getting will help keep any salt crystals moving through, or preventing them from building up in the cooling system.
Fresh water flushing is ideal if that can be achieved, but if moored at your dock, highly unlikely, unless you can load her back onto a trailer, or rig up a push-on hose fitting??
As part of your maintenance regime, lift the cowling and give a generous spray of a good quality protectorant (Inox or a lanolin based product), all over the engine.

Edit...If the cooling water 'tell tale' slows or stops, it is quite often simply a built up of crust, right at the outer discharge point. This is easily fixed by poking a small cable tie or wire (or compressed air) up the hole and clearing the dried crud (silt, sand or salt).
 
Last edited:
Some modern outboards have a hose attachment point to allow flushing via a hose from the pontoon. Assuming your's does not, invest in a set of "muffs", not expensive. Regular use will help prevent salt bunging up the cooling, but it will nevertheless accumulate. I dismantled an old O/B a few years ago as it was not showing a tell-tale water stream when running and the cooling chanels where completely clogged.
Fresh water flushing is well worth the trouble.
 
Welcome to the forum.

Later models of the Mercury 150 have a flushing plug. I am not sure where it is located, as I do not have a manual.

But it should take a standard screw in hose adapter ( Not sure if you have Hozelock in the States) but it is the equivalent to this (Click to view)

It is designed to allow you to flush the engine while it is still in the water, but with the engine raised. But, whatever you do, do not run the engine while using the flushing plug, that can only be done with the engine vertical and using flushing muffs.

This is an old post I made on the subject, with a picture, but on a Suzuki.
 
Would think you could be doing more damage by tilting the motor rather than salt damage. The rams need to be closed rather than open, leading to barnacles, rust and wear.

I dont think many folk bother flushing outboards, but you could poke out the gunge every few years.

You wont have damaged the motor, less the motor has become over heated, but this wont happen for a good few years. Fresh water will help but wont stop the crystals forming.

Folk here clear it out with brick cleaner/acid.Though a poke with a screw driver works just as well.

AS said above, if water is coming out the other end, it's fine. if not, it needs investigating.
 
Would think you could be doing more damage by tilting the motor rather than salt damage. The rams need to be closed rather than open, leading to barnacles, rust and wear.

On an outboard the tilting rams are never in the water and it is unlikely barnacles can jump that high.

My outboard is tilted up 99% of the time (Only down when I am actually using it) and is still fine after 6 years with no sign of barnacles, salt damage or wear on the rams.

I would recommend regular flushing, especially in hot environment, as the salt inside the engine will dry quickly and build up blocking the channels. Think of it this way. Salt bad for engines, so always flush.

Also make sure you check the large anode that is usually hidden under the lowest point of the transom mount and looks like this

19946.jpg
 
On an outboard the tilting rams are never in the water and it is unlikely barnacles can jump that high.

My outboard is tilted up 99% of the time (Only down when I am actually using it) and is still fine after 6 years with no sign of barnacles, salt damage or wear on the rams.

I would recommend regular flushing, especially in hot environment, as the salt inside the engine will dry quickly and build up blocking the channels. Think of it this way. Salt bad for engines, so always flush.

Also make sure you check the large anode that is usually hidden under the lowest point of the transom mount and looks like this

19946.jpg

Sorry, your right, I was thinking of out drives.

Still dont think it's a cardinal sin to miss flushing the engine. Lets face it, all engines would be better flushed each time, but not many ever get it.
 
Just a couple of things I would add. Keeping a large engine tilted is not problem so long as you let the weight of the engine be taken by the tilt lock. Otherwise weight / pressure on ram will cause wear. I always flushed my old boat's outboard, it did have sideflush facility but IMHO it was easier to tilt engine up, slide on flushing muffs with hose attached and drop engine back in water and flush. If you use side flushing attachment and leg is sitting in the sea it will still bring salt water up the leg and in the engine. With muffs fitted well it will only bring in the fresh water which is the general aim... obviously side flushing function is great if boat sitting out the water.
 
Just a couple of things I would add. Keeping a large engine tilted is not problem so long as you let the weight of the engine be taken by the tilt lock. Otherwise weight / pressure on ram will cause wear. I always flushed my old boat's outboard, it did have sideflush facility but IMHO it was easier to tilt engine up, slide on flushing muffs with hose attached and drop engine back in water and flush. If you use side flushing attachment and leg is sitting in the sea it will still bring salt water up the leg and in the engine. With muffs fitted well it will only bring in the fresh water which is the general aim... obviously side flushing function is great if boat sitting out the water.

It has been discussed on here before and I have been told by Suzuki UK HQ that a tilted outboard does not need any support, except when in transit - on a trailer. Their words were, it is what the rams are built for.

I have tried to flush with muffs while my boat was in the water, and other than getting in the water there is no way I can reach to put the muffs safely and if I did manage it, why reintroduce the leg back into the salt water.

1285206781_0aba2b2254_b.jpg


The side flush is designed to be use with the leg in the raised position, so why drop it back into the water?
If the boat is out of the water, then why use the side flush when I can easily slip the muffs on?
I have flushed with the side flush, summer and winter, for six years with no problem, especially as I have made up a short length of hose and with connectors that can be fitted safely from the stern.
 
I'm with the Major on this one. We used to have the same setup and I did the same, made up a dedicated short hose with attachments to make it easier to fit the flush attachment, flush the engine in the tilted position, and leave it in the tilted position afterwards.
So far as I'm aware, all outboards are left in the tilted position when not in use, but I've never seen one with the tilt lock engaged. Only time they're blocked up is when they're being trailered. Can't see how leaving them raised would put any extra load on the hydraulics or increase wear and tear as they're double acting.
 
It has been discussed on here before and I have been told by Suzuki UK HQ that a tilted outboard does not need any support, except when in transit - on a trailer. Their words were, it is what the rams are built for.

I have tried to flush with muffs while my boat was in the water, and other than getting in the water there is no way I can reach to put the muffs safely and if I did manage it, why reintroduce the leg back into the salt water.

1285206781_0aba2b2254_b.jpg


The side flush is designed to be use with the leg in the raised position, so why drop it back into the water?
If the boat is out of the water, then why use the side flush when I can easily slip the muffs on?
I have flushed with the side flush, summer and winter, for six years with no problem, especially as I have made up a short length of hose and with connectors that can be fitted safely from the stern.


...:D as always it seems to depend on the "expert" you speak to!! ............I was told by the Suzuki dealer who serviced my engine to always avoid running engine fully tilted (hence why I always tilted back down to vertical to flush) and to always drop engine down to rest on tilt lock to reduce stress on the ram & pump....(which once again I always did)....it always seemed to make sense to me....

...just hope I don't have sleepless nights over this controversial issue ;-0
 
When you use the flushing attachment with the engine tilted, it's not running, the mains water pressure is sufficient to flush the system and force water through the tell-tale as shown in the Majors pic.
No sleepless night for me, my outboards long gone! ;)
 
When u side flush with the engine tilted you don't have it running......it runs through the system via gravity if that makes sense !! Hi James just to let Firefly is alive and well......been out about 20 times this winter in all sorts.....I think she wishes she was back on the South coast !!!
 
Last edited:
...:D as always it seems to depend on the "expert" you speak to!! ............I was told by the Suzuki dealer who serviced my engine to always avoid running engine fully tilted

See my first post. "But, whatever you do, do not run the engine while using the flushing plug, that can only be done with the engine vertical and using flushing muffs."
So, never ever ever ever ever ever run the engine when using the flushing port.

As soon as I arrive back in my berth I tie up, turn the fuel off, raise the engine, fit the hose and turn on the water to do the flush while the thermostat is still open.

Once that is happening I can attend to all the other jobs and put the kettle on while it happily cleans out the nasty salt.

I see the OP has gone missing.
 
Last edited:
Top