Fresh water flushing of Mercrusier with alpha one drive

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achris

More fish than mountain goat
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Try this...

In the middle of the water inlet hose put a quick connect. Male on the engine end, female on the drive end. Have a 2 or 3 metre hose with a male end and a water/garden hose with female end.

When you want to flush, disconnect the drive hose and connect the open ended hose and point it over the side. Connect the garden hose to the engine end and run the engine to fully flush.

When you're done just disconnect the open ended hose and the garden hose and reconnect the drive and engine hoses back together...

You could even store the open ended hose on the end of the garden hose so it doesn't get lost...

Chris....
 

silver_power

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My set up is 350 mag mpi/alpha GENII raw water cooling and I flush the engine every end of weekend while the boat is docked. I made two adapters with quick connect fittings. The one adapter fits at the hose coming from the drive and the other at the steering cooler in which I supply the engine fresh water from the marina tap. I connect a water hose (2m length) to the adapter fitted to the hose coming from drive so to bypass the salt water coming from impeller and I start the engine. I adjust the flow of the fresh water so the engine temp to be steady above 72oC let's say 80oC so to secure that the Tstat is open and so the fresh water inserts to the block. It is really simple and good system. I use it for 2 years now. I thing this is the most simple and cheap way to flush the engine with fresh water with boat docked.
 

silver_power

Petty Officer 1st Class
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One other advantage of this method is to check and measure real time the water suplied from the impeller at every rpm range! Really useful!!
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
My set up is 350 mag mpi/alpha GENII raw water cooling and I flush the engine every end of weekend while the boat is docked. I made two adapters with quick connect fittings. The one adapter fits at the hose coming from the drive and the other at the steering cooler in which I supply the engine fresh water from the marina tap. I connect a water hose (2m length) to the adapter fitted to the hose coming from drive so to bypass the salt water coming from impeller and I start the engine. I adjust the flow of the fresh water so the engine temp to be steady above 72oC let's say 80oC so to secure that the Tstat is open and so the fresh water inserts to the block. It is really simple and good system. I use it for 2 years now. I thing this is the most simple and cheap way to flush the engine with fresh water with boat docked.

I think this is exactly what I suggested...
 

Davidsgara

Seaman
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Jan 25, 2019
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Thanks Guys great idea.

Do you know if I can get the quick connect fittings in stainless Steel? Or should I just get plastic fittings?
Also were you able to get the quick connect fittings in 1 1/4 inch?
 

achris

More fish than mountain goat
Joined
May 19, 2004
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27,468
Use the Merc ones. Supplied on later model Bravo engines. Do the same job, and only about $10 each...

22-865362 and 22-865364 (you need 2 of each) (you'll need to check the size. You didn't say what engine you are working on)

Chris.........
 

Davidsgara

Seaman
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Jan 25, 2019
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It’s a 5.0 Mercrusier- 1 1/4 hose size.

i think the bravo ones you suggested should be the same size?

Thanks
 

silver_power

Petty Officer 1st Class
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I made these adapters to a machine shop and they are made from Teflon. Perfect fit.
 

jpitz31

Recruit
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Jun 28, 2022
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I know this is an old thread, The new super flush is all plastic now and $300.
I was thinking of making my own. If you replace the engine block plugs with fittings, would you have to use a check valve or a plug with a shutoff valve. I would think that when the engine is running the water in the block would pump out to the heat exchangers. I know you can get fittings with valves, but do they make check valve fittings?

Thanks
 
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