Winterization Questions

[FishingFool34]

First year winterizing an I/O and I have done lots of research... I'm confident I know how to do it. My question is which method to do. I've come across 3 methods that all seem to be fairly popular.

1)Drain water all water from the block and leave it empty (air can't freeze)
2) Anti-freeze via muffs method
3) Drain water from block and pour in anti-freeze via removing the t-stat hoses

Then there is the added wrinkle of doing either anti-freeze method and then draining the anti-freeze from the block also. Idea behind this being again air can't freeze and any liquid left in the block would likely be straight anti-freeze. 

 

After searching here and seeing Pap's old experiment with freezing anti-freeze in a glass jar and how little water it took to get mixed with the AF for break the glass has me a little concerned. I'm leaning towards method #3 and then draining the block again, curious to hear some opinions.

[jth21usa]

I have alway done #3, pull the plugs, drain the block and poor antifreeze into the hoses. I never had any issues. Frankly I think most of the people who have issues miss a plug somewhere. 

[Bad Habit]

I have also done #3 for many years without a problem. I just make sure I use a quality anti-freeze rated for at least -50 degrees burst. Make sure after you remove the plugs you clean the hole out with a wire or something else. My holes are always restricted or completely plugged with dirt and debris.

[lrg355]

When you drain the block make sure it is completely drained especially if you dock or run in a muddy area. I always pull the drain plugs, let it drain, pull the lower end of the water pump hose, and some other hoses. I then use compressed air and a cone shaped fitting to blow into the block and headers. Plenty more mud, sludge and water still comes out. Started this procedure after a friend lost a block to trapped mud and water when he thought the water was all out.

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[High Bidder]

If you have a power steering oil cooler don't forget to blow it out and add antifreeze. Maybe not all IO's have them. I'm only familiar with mine.

[Earl28]

Do not forget the other water pumps, ex. Deck wash down.

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[dt5150]

had a buddy of mine who is a mercury certified marine tech (tech at a local marina) come over to help winterize my 5.0 mercruiser. he did option 3. used about a jug and a half of antifreeze. then we did the lower unit gear oil. he pinched off the hose from the reservoir so all the fluid in it stayed there, then drained and filled the lower unit. i'm new to the world of i/o's so this was a learning experience for me. next year i'll do it myself, easy.

[FishingFool34]

I went with option 3 myself. Along with changing engine and lower unit oil on main and the kicker. Also made sure to get washdown/livewell pump, both fish box pumps, and water tank. Also gave the boat a good wash and quick wax, fingers crossed everything turns out alright! 

[dt5150]

i did the lower unit oil and engine oil/filter in the kicker as well. i know what you mean by fingers crossed though, it's just one of those wait and see kind of things. i wish i had a nice big heated barn!