Merc I/o Winterize issue

cjm13905

New member
Merc Cruiser 5.0 L I/O
I have been doing my own winterization for about 13 years now.
I get the engine warmed up, put on muffs that are connected to a 5 gal bucket of antifreeze and
run 5 - 6 gallons in until it starts spitting out.
This year, I could not get the muffs to work and have the engine draw up the antifreeze.
The only thing I can think of is the muffs are 12 years old, and have spread apart and don't provide
enough pressure against the motor to have the antifreeze sucked in .

Any other thoughts ?

Because of this, I'm considering doing the blue Wing nut method.
The thing is, I can never find the first plug, under the engine, and I have tried several times.
Can someone confirm there is one there ?
My major concerned is about having the ability to put this plug back in, without seeing where it goes.
Thoughts on this as well ?

My instructions for winterizing by draining via blue wing nuts are, thoughts on these as well ?
  • Start engine and run till temp is 120 degrees
  • Lift Boat completely out of water
  • Be careful, engine and water is HOT!
  • Crank Engine, but do not start, for 1 second.
  • All plugs to be removed are blue Wing nut like. Keep track of what plug went into which location and replace in the same location. There are 6 plugs. Remove and let water drain.
    • First plug to remove is underneath the engine. Place left hand on fan belt, and reach underneath for plug.
    • Second plug to remove is in middle of right side of engine behind a few hoses.
    • Third plug to remove is on right front side of engine.
    • Fourth plug is way at bottom on left side of engine, between plywood board and engine.
    • Fifth plug is little bit higher than fourth plug.
    • Sixth plug is right in front of engine.
  • Remove the 4 hoses up front. Use a Hose removal tool.
  • Put blue plugs back in
  • Buy extra plugs for emergencies.
  • Pour Anti Freeze in Back left hose, about ½ gallon.
  • Pour Anti Freeze in Back Right hose about ½ gallon.
  • Pour Anti Freeze in Front Left hose. Pour till starts to come out other side, then cup palm over where it is coming out and continue to pour to fill other parts of the engine.
  • Pour Anti Freeze in Right Front hose. After ¼ gallon is in, put nozzle of anti freeze container directly into hose, and squeeze the bottle. This will force the anti freeze into the engine and do this until you hear/see it drip out of the engine and into the water.


Thanks all.
 
If you go to www.marineengine.com you should be able to find illustrated parts breakdown for your engines year and serial #. Hopefully this will show you all the plug locations. My 2001 chap had six plugs and they were a PITA to find. My 2007 only has four with the single point drain system so much easier. All other steps you outlined is exactly as I have done for years with the exception of taking a piece of wire or screwdriver to clear any blockage you might have once each plug is removed.
 
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Don't let anyone tell you if you can't find it, don't worry about it. When I sold my 2001, I told the buyer(a friend) that I would help him winterize it the first year due to the six drain plugs and the difficulty in finding all six. He didn't listen and had to put a new engine in the next year due to a cracked block.
 
How old is the impeller? If its old, it may have a hard time pulling the AF into the engine.

I take it that you have a open coolant system. Yes?
 
Impeller is 2 years old. Not sure what an open coolant system is, but the engine only uses water drawn in from the lake to cool the engine.
 
To me the easiest way to tackle this is get a new impeller [you might need it anyways] and a new muff. I just used the West Marine 5 gal container and pumped in 5 gallons of antifreeze. The container sits above the drive so the antifreeze pushes down rather than the engine trying to pull it up. All those plugs seem like too much work.
th
 
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I would change out the impeller. I always do it every 2 years. Its worn so its not sucking up the water/AF like a new one.

A closed system is like a car. So no sea water runs thou the block. Rather than a radiator, you have a heat exchanger. Much easier to winterize.

I use a 5gal bucket, and drill a hole in the side for a quarter turn hose shut off. Much cheaper and I found that the threads on the kit's container leak after a few years. But thats me.....
 
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To those using this quick crack method of sucking the AF in let all of us know how it worked out for you.
Unless you drain everything first your at risk for failure.
 
How do you warm the engine first and then open the drains without cooking your hands? Assuming you're going to add AF.
 
If you go to www.marineengine.com you should be able to find illustrated parts breakdown for your engines year and serial #. Hopefully this will show you all the plug locations. My 2001 chap had six plugs and they were a PITA to find. My 2007 only has four with the single point drain system so much easier. All other steps you outlined is exactly as I have done for years with the exception of taking a piece of wire or screwdriver to clear any blockage you might have once each plug is removed.

To me the easiest way to tackle this is get a new impeller [you might need it anyways] and a new muff. I just used the West Marine 5 gal container and pumped in 5 gallons of antifreeze. The container sits above the drive so the antifreeze pushes down rather than the engine trying to pull it up. All those plugs seem like too much work.
th
This is basically my set up, only with a 5 gallon bucket. I put it on the swim platform, so it is above the drive and flows down.
 
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To those using this quick crack method of sucking the AF in let all of us know how it worked out for you.
Unless you drain everything first your at risk for failure.
I'd say this method also depends upon where you live. My boat is on the VA/NC border. Sits about 2 ft above the water all winter, and the water doesn't get below 40 degrees. That fact that the air temp rarely gets below 32, and that the boat sits above 40 degree water, I think the muff method is okay even if it leaves a bit of water in there. So far 13 years no issue.
 
How do you warm the engine first and then open the drains without cooking your hands? Assuming you're going to add AF.
The only blue drain screw I cannot set, nor find at this point, is the one under the engine. If you can see the blue wing nuts you can wear a glove and get them off, but the one I can't find'/see is the big issue.
 
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Merc Cruiser 5.0 L I/O
I have been doing my own winterization for about 13 years now.
I get the engine warmed up, put on muffs that are connected to a 5 gal bucket of antifreeze and
run 5 - 6 gallons in until it starts spitting out.
This year, I could not get the muffs to work and have the engine draw up the antifreeze.
The only thing I can think of is the muffs are 12 years old, and have spread apart and don't provide
enough pressure against the motor to have the antifreeze sucked in .

Any other thoughts ?

Because of this, I'm considering doing the blue Wing nut method.
The thing is, I can never find the first plug, under the engine, and I have tried several times.
Can someone confirm there is one there ?
My major concerned is about having the ability to put this plug back in, without seeing where it goes.
Thoughts on this as well ?

My instructions for winterizing by draining via blue wing nuts are, thoughts on these as well ?
  • Start engine and run till temp is 120 degrees
  • Lift Boat completely out of water
  • Be careful, engine and water is HOT!
  • Crank Engine, but do not start, for 1 second.
  • All plugs to be removed are blue Wing nut like. Keep track of what plug went into which location and replace in the same location. There are 6 plugs. Remove and let water drain.
    • First plug to remove is underneath the engine. Place left hand on fan belt, and reach underneath for plug.
    • Second plug to remove is in middle of right side of engine behind a few hoses.
    • Third plug to remove is on right front side of engine.
    • Fourth plug is way at bottom on left side of engine, between plywood board and engine.
    • Fifth plug is little bit higher than fourth plug.
    • Sixth plug is right in front of engine.
  • Remove the 4 hoses up front. Use a Hose removal tool.
  • Put blue plugs back in
  • Buy extra plugs for emergencies.
  • Pour Anti Freeze in Back left hose, about ½ gallon.
  • Pour Anti Freeze in Back Right hose about ½ gallon.
  • Pour Anti Freeze in Front Left hose. Pour till starts to come out other side, then cup palm over where it is coming out and continue to pour to fill other parts of the engine.
  • Pour Anti Freeze in Right Front hose. After ¼ gallon is in, put nozzle of anti freeze container directly into hose, and squeeze the bottle. This will force the anti freeze into the engine and do this until you hear/see it drip out of the engine and into the water.


Thanks all.
What year is your boat? Some 5.0 L only have 5 drain plugs per video below.

 
What year is your boat? Some 5.0 L only have 5 drain plugs per video below.

Mine is a 2000.
Thanks for the video. His engine compartment is quite spacious.
I can barely get the battery in and out, and getting a look see at the transom is
near impossible.
 
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Here is IBP for a 5.0L that shows six drain plugs, impossible to know if this your exact setup without serial #. Hope this helps.

1730312129086.png


1730312007486.png
 
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A closed system is so easy to winterize. I had a Volvo (Mercs you could use muffs) which had a hose connection for flushing the engine. I would connect the AF bottle/container to the flush hose. Start the engine with 30 sec the AF can out by the prop. Done, all the water was removed.
 
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