Flushing raw-water cooling system while still in water

Cresco750

Petty Officer 2nd Class
Joined
Jul 7, 2012
Messages
192
Hi
Is there some relatively simple way to flush a raw water cooled Mercruiser 228 / R leg while the boat is still on the water? I guess one way would be to perform some level of acrobatics and lean over the back and try and slip on a set of flush muffs and hose but that would be extremely difficult for me.

Can some sort of garden hose fitting be installed in the cooling system plumbing that would allow fresh water to be flushed through? Of course this would only be any use while the engine wasn't running so as not to draw water in via the leg pump, but then I'm thinking the thermostat would prevent circulation of cold water? Perhaps an in-line tap which shuts off the feed from the leg pump and another one down stream which allows inflow from a hose?

As a resort, has anyone had any first hand experience with the Salt Away direct injector, and how well it prevents corrosion when mixed with sea water in the cooling system during inactivity?
 

04fxdwgi

Senior Chief Petty Officer
Joined
Jun 10, 2011
Messages
754
Re: Flushing raw-water cooling system while still in water

Hi
Is there some relatively simple way to flush a raw water cooled Mercruiser 228 / R leg while the boat is still on the water? I guess one way would be to perform some level of acrobatics and lean over the back and try and slip on a set of flush muffs and hose but that would be extremely difficult for me.

Can some sort of garden hose fitting be installed in the cooling system plumbing that would allow fresh water to be flushed through? Of course this would only be any use while the engine wasn't running so as not to draw water in via the leg pump, but then I'm thinking the thermostat would prevent circulation of cold water? Perhaps an in-line tap which shuts off the feed from the leg pump and another one down stream which allows inflow from a hose?

As a resort, has anyone had any first hand experience with the Salt Away direct injector, and how well it prevents corrosion when mixed with sea water in the cooling system during inactivity?

http://www.iboats.com/Flush-Pro-tra...87458587--session_id.306660874--view_id.39356

Flushing adapter located here on iboats.

I built an actual bronze flushing manifold for mine, as the clear plastic adapter below the water line concerns me a bit.
 

Cresco750

Petty Officer 2nd Class
Joined
Jul 7, 2012
Messages
192
Re: Flushing raw-water cooling system while still in water

Interesting gadget, but I don't think it would allow the engine to be running in order for the thermostat to open? I may be wrong here, but wouldn't the water pump in the stern leg override the spring loaded check valve and allow sea water to bypass?
I'm thinking maybe I will make up some sort of system using a couple of brass or stainless ball valves.

Cheers
 

dingdongs

Chief Petty Officer
Joined
May 29, 2009
Messages
649
Re: Flushing raw-water cooling system while still in water

you could always take the supply off where it comes from the rear to the thermostat housing and connect a longer pipe to throw the salt water over the rear of the boat whilst engine is running.connect a hose with fresh water to the thermostat housing to give a supply for flushing purpose.
 
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