Best way to flush your engine

[pjsomers2]

"Hey I have always flushed my engine with the muffs, my new engine has a hose connection that looks like a way to flush the engine as well, but I have no knowledge on how to go about it do I hook a hose to it and run the engine or is it just a flush and the water pressure is all I would need. Its on a 2003 8.1 hose goes right into the cooling system just not sure if it works the same as the muffs or has its own way of working. Any help would be great Thanks Joe"

[RicardoMarine]

These systems are primarily used whereby the boat is moored in salt water.
It allows the sea water pump "pull" potable water in and through the engine while it is running.
Some systems allow for salt neutralizing agents to be introduced into the cooling system.
These are fine if you allow operating temperatures to open the engine thermostat!
Turn the supply OFF simultaneously with (or just ahead of) shutting the engine down!

DO NOT use this system to winterize a raw water cooled engine unless you know exactly what you are doing!
Some advertise these as a winterizing tool! Be careful!

.

[davesboat]

"I had one of those connections on my engine, I cut the blue cap off and connected my "neutra salt" system to it with clear hose, I can see the solution being added while I press the flushing switch."

[RicardoMarine]

"Well, that's the thing we must be careful with!
These systems should only be used via a running engine's sea water pump and should NEVER be used to force or pressurize the solution into a NON-Running Engine!"

[pjsomers2]

"Ricardo, So basically I should not use it since mine is a raw water cooled engine? Just a little confused. I do remember reading that it was used while in the water moored, so I suppose I wont be using it since I trailer my boat. Most of the time I am in fresh water, just looking for the best way to flush when I do take it to the salt water. Thanks"

[sandkicker]

"Joe,
What Ricardo was saying...make sure engine is running! My boat (w/5.7L FWC engine) lives in salt water and I had a flush port plumbed into the raw water intake (which I had moved from thru-the-drive to thru-the-hull w/strainer). To avoid damage to the pump and to keep track of water flow to the engine, I attach a short garden hose ( 4 ft) to the flush port and stick the other end in a 5 gal pail. I fill the pail with water with a garden hose and let the hose keep running. I start the engine and monitor the water level. What I found, is that even with the hose running wide open, the water flow from the hose cannot keep ahead of the water demand of the 5.7L engine, even at idle."

[RicardoMarine]

"NO... I'm not suggesting that you not use this if moored in Salt Water. If you are in salt water, this can be fine for flushing each time you come back in.
However, if you trailer this boat, there is no need to use a ststem like this when you can attach the garden hose via the muffs.

And just to clarify here;
I am not suggesting that we not use a system like this!
What I am suggesting is that we fully understand the use and the "Misnomer Use" that these sellers imply... I.E.; winterizing!
Quite frankly, I am disappointed when I see them advertise that you can Winterize with them!!!!! Errrrh!

For anyone attempting to "winterize" by sucking up anti-freeze through the system and then thinking that they have fully protected their engine/exhaust, is a huge gamble, IMO......... UNLESS they fully understand their system and how to do this at operating temperature with the "T" stat open!
And even then, on any Raw Water cooled engine, it is always best to pull the engine block drain plugs (air won't freeze).
I'll bet you that somewhere on your instructions it implies that you can winterize with this!

Sorry to get side tracked on Winterizing this early in the season, but when I hear of these systems and how often they are misunderstood..... yikes..............!


Robert, I don't see quite the problem if the garden hose can't quite keep up with no load on an engine. The impeller will still be wet, and a low water flow, at low engine load, usually won't harm anything with regard to exhaust components for the short duration of flushing!
It's that high water supply at at low RPM that I don't care for when shutting an engine down.
But that's another story for another day!

."

[davesboat]

"--------------------------------------------------------------------------------
Well, that's the thing we must be careful with!
These systems should only be used via a running engine's sea water pump and should NEVER be used to force or "

[sandkicker]

"Rick... T'was just an indirect warning not to run for prolonged periods of time or at other than idle.., i.e., just flush when on a hose."

[am_dew]

"Maybe this is a different situation, and if so please disregard this post, but I have always used a hose attached to the suction side of my AQ130C's (RWC) H2O pump when I need to start/run the engine while trailered. I am very careful to use low water pressure, just enough to keep the engine temp normal. I could never find any muffs to work right on my 270 drive."

[RicardoMarine]

"Bob, I'd encourage you to find and use the muffs!
Reason; This is the normal path for the sea water, and if we have a problem, this may find it prior to you being on the water.
Examples:
**Water neck fitting condition.
**Lower unit pivot tube O-ring seal.
**S hose failure.
**Suction hose failure.

To me, these are good reasons to use the muffs over that of simply supplying water and circumventing a portion of the system.

Remember, parts of this system come up and out of the water when we are up on plane!

All of this is IMOO! Each to his own!"

[am_dew]

"Point well taken Ricardo, thanks.

Can anyone recommend a set of muffs that work well on the lower unit of a 270? All the ones I've tried just don't align up with the intakes."

[pjsomers2]

"O.K. I am understanding now, thanks guys for the info."