Winterizing for in water - engine raw water drain

gcarmich

Seaman
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Jan 8, 2009
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I have 2005 MAG 350 MPI engine S/N 0W067905. I have my Cool Fuel module removed so I cant run engine to winterize by flooding engine with antifreeze. I removed the 5 blue plugs from the engine to drain cooling water. I am concerned that the engine block still has water in it. Do I need to drain the block separately? If so, how do I drain block? Thx, Gil
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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by blue plugs, you mean the plastic wingnut thingies on the bottom of the J hose, each side of the block and the bottoms of the manifolds?

if so, youre drained.

drained = winterized.

now work on the annual drive maintenance. there is a sticky in the engine forums on winterization.
 

gcarmich

Seaman
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Jan 8, 2009
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66
Yes. Blue plastic wingnuts with threads but mine were not under manifolds. One was on port down low where hoses came together. Two on starboard near water pump? One up top on center forward area. And one on cool fuel module. Drive is underwater but ill look for the winterization guide. Thanks!
 

Scott Danforth

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Yes. Blue plastic wingnuts with threads but mine were not under manifolds. One was on port down low where hoses came together. Two on starboard near water pump? One up top on center forward area. And one on cool fuel module. Drive is underwater but ill look for the winterization guide. Thanks!
You can't winterize while in the water
 

Scott Danforth

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Plus I will add that is you pulled the drain plug from the little manifold under the motor and nothing came out, the whole drain system is clogged.
 

Lou C

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Sounds like that boat has to get pulled out and the drain holes need to be rodded out. Very risky to do otherwise.
 

ROY WILLIAMS

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Aug 8, 2022
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I have 2005 MAG 350 MPI engine S/N 0W067905. I have my Cool Fuel module removed so I cant run engine to winterize by flooding engine with antifreeze. I removed the 5 blue plugs from the engine to drain cooling water. I am concerned that the engine block still has water in it. Do I need to drain the block separately? If so, how do I drain block? Thx, Gil
ANTIFREEZE COOLANT 50%-DISTILLED WATER 50% ENGINE! YES!
 

Scott Danforth

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Still can't winterize while in the water

It's like trying to keep your shoes clean while mucking the cow stalls while sitting 3 ft deep in the muck
 

Lou C

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Nov 10, 2002
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Some inboards are left in the water here, over winter, but I'd never do it with an I/O. Not sure what you'd do about the water still in the Y pipe!
 
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