First time winterizing 4.3 mercruiser, alpha one.

[jon1440]

So far I'm unclear on what is actually being winterized. I know water is being sucked up through the lower unit and then circulating through the motor and out the exhaust. At this point I've removed the blue plugs (5) and drained. Poked the holes to make sure there was no blockage.

I've see people put the muffs on and pull in the marine antifreeze from the lower unit and wait until I see the water color change coming out the exhaust.

Is there an easier way of filling the block from the hoses on top of the motor? Or is running it while filling better? I'm sure I'm not the first to think it, but if no fluid is in the block to freeze then should put anything in it?

So far my plan is to go get garden hose T fitting with shut off valves and run fresh water with boat running until thermostat opens and then open antifreeze valve and close fresh water valve. Then wait until antifreeze starts coming out the exhaust. Shut off engine and cross fingers this is good enough.

Through my search I seen someone get the motor full and then pull the plugs to drain. Not sure what the point is of putting in the antifreeze if you drained right after.

 

[Bt Doctur]

So far my plan is to go get garden hose T fitting with shut off valves and run fresh water with boat running until thermostat opens and then open antifreeze valve and close fresh water valve. Then wait until antifreeze starts coming out the exhaust. Shut off engine and cross fingers this is good enough.

Yep, quickest way to block replacement

Flush. fog till motor stalls, drain everything

Remove the large hose from the T housing and pour in AF until it comes out the top of the housing, replace hose, remove manifold hoses from the housing and pour about 3/4 of a gallon in each, replace hoses

 

[QBhoy]

Exactly as above stated. To the point and absolutely correct, in my opinion. Bloody YouTube…has a lot to answer for. Wish people would stop making videos taking AF in through muffs. Silly carry on.

 

[Drcoffee]

I have watched so many videos with bad ideas. This guy does a nice job and shows how to do it fast and easy

 

[Lou C]

The problem with the suck AF up the drive method is that most people don’t understand how raw water cooling works. The system has excess capacity and to keep the engine warm enough the thermostat functions as a gate valve. It only opens as needed to keep the engine temp close to the temp rating of the ‘stat. Contrary to what some may believe cooler is not always better. Your engine needs to maintain at least 140*F to live a long life; 160 would actually be better. So when the engine is under load the water heats up enough (140-160*F) to keep the stat open. But at idle with no load on a cool fall day it may not. Your temp gauge may read normal but that doesn’t mean that the stat is open far enough to let all the raw water exit the block.
What misleads people is they see water exiting under the transom mount but that’s because the exhaust system is the exit for the raw water system. The only time water exits the engine is when the water in the block is hot enough to keep the stat open. That’s why sucking in AF is risky the block may still be full of mostly water.
So either drain it & poke the holes & leave dry, or drain,poke holes & fill with AF after manual draining via the hoses. I’ve done it that way 20 years with no problems. Simple but don’t take short cuts!

 

[Scott Danforth]

Change engine oil and filter
Pull the 5 drains and poke each port with a stiff wire
Pull the large J hose and drain
Pull the drive and inspect the u-joints, gimbal, and bellows. Replace the raw water pump if needed

You are now winterized per the manual

Optional: if you want antifreeze pour into the thermostat housing with a funnel

Preferred to keep the drive off during winter

Nowhere in the factory manual do they say use a block-buster 2000 scamco kit

Now, if you really want to suck up antifreeze with one of those kits. You need to first change the oil, drain everything, pull the drive and do the winter service. Then install the drive. Fill the scamco kit up with AF. Make sure you have a siphon going to the drive so you don't toast your impeller. Then start the motor.

A funnel is cheaper and faster

 

[jon1440]

Unfortunately my starter went belly up while sitting in the drive so the siphon method was not used. After twiddling my thumbs for far to long I went old school and probably the quickest method by far. Grabbed a rachet/socket and screwdriver and went to work. Dumped winterizer straight into the manifold until it wouldnt take anymore then dumped it down the j hose. Actually poured down all of them to understand where water was going. Also pulled a couple plugs on the manifolds and poured there as well.

 

[Scott Danforth]

Unfortunately my starter went belly up while sitting in the drive so the siphon method was not used. After twiddling my thumbs for far to long I went old school and probably the quickest method by far. Grabbed a rachet/socket and screwdriver and went to work. Dumped winterizer straight into the manifold until it wouldnt take anymore then dumped it down the j hose. Actually poured down all of them to understand where water was going. Also pulled a couple plugs on the manifolds and poured there as well.

did you drain the block and manifolds first?

 

[jon1440]

Yep drained first. That’s why it didn’t make sense to drain then flow fresh water with winterizer. Not that that’s what was being advised here. Just seen others showing that.

I drained what I could and filled block up with winterizer until it wouldn’t take anymore.

 

[Lou C]

You can't go wrong, by draining everything and verifying that it actually drained first. Then if you want to add AF, pick one that will stay liquid down to the lowest temp you anticipate. And just pour in via the hoses. Easy, no risk of burning impellers etc.

 

[poconojoe]

I hope you drained it all when you were done.
I wouldn't keep any liquid in my block over the winter.
I get adding AF, but if there's any water left in there it will dilute the AF and it may not be as effective as you might hope.
It's just not worth the chance.
I do the AF thing, but when I'm all done, it all gets drained.
Just my opinion.

 

[Lou C]

I leave it in. If you’re going to drain the AF out save your money. I leave it in for corrosion protection which is exactly what Merc advises in their manuals. If you use the RIGHT AF (-100 or do as I do mix up a batch of Sierra No Tox PG AF) you will NOT have a problem. 20 years worth of winters doing it this way with temps down to zero.
PS
34 year old engine used in salt water 20+ years, never flushed till end of every season. Heads were replaced (overheat damage) but block & intake manifold are original. Still not rotted through. That’s why I advise this method but in freshwater corrosion is so much less you probably don’t have to worry about using AF. It’s in every late model Merc manual I’ve looked at though. Fill seawater side of cooling system with antifreeze after draining for winter storage is what they say. Just use the right stuff.

 

[tonyjh63]

Exactly as above stated. To the point and absolutely correct, in my opinion. Bloody YouTube…has a lot to answer for. Wish people would stop making videos taking AF in through muffs. Silly carry on.

Ok, I'm not arguing with either you or Bt Doctor (I don't know enough to do so), but WHY is that method outlined earlier (pulling AF through the outdrive) a bad idea that leads to damaged engines? Thanks!

 

[Lou C]

I answered that question above, post #5. You have to learn how raw water cooling works.

 

[Scott06]

Ok, I'm not arguing with either you or Bt Doctor (I don't know enough to do so), but WHY is that method outlined earlier (pulling AF through the outdrive) a bad idea that leads to damaged engines? Thanks!

Without draining water out first you risk nit completely getting enough AF through block to prevent freeze damage. marinas will do this on alrgers boats but they have huge tanks with large amounts of af that they run the engine in to ensure complete replacement of water with topped off AF. big diff between this and running the 5 gal bucket of AF through

 

[Scott Danforth]

Ok, I'm not arguing with either you or Bt Doctor (I don't know enough to do so), but WHY is that method outlined earlier (pulling AF through the outdrive) a bad idea that leads to damaged engines? Thanks!

You should understand how thermostats in raw water cooled engines work.

Without draining, AF would never get to the block. Only go out the exhaust

 

[poconojoe]

I run -100 degree AF through the engine as an added protection for both freeze protection and anti corrosion. It also helps me sleep without worry through the long cold winters hear in PA.

I may be wrong, but the way I look at it is if there's any water trapped in corners of the engine after draining, it may freeze. Such little water will probably not cause damage, but I just feel better knowing the AF is there.

Plus, I know for a fact that after completely draining the engine, manifolds, etc, there's always water remaining in the intake manifold of my 4.3 Mercruiser. I've seen it through the thermostat housing when replacing the thermostat after draining.

I do understand that "air don't freeze ". That's why I completely drain everything afterwards. So, the AF is just a precaution, maybe the best of both worlds.

I do pull the AF through the outdrive and no disrespect to the experts here, but when I pull the 5 drain plugs, AF pours out of every single one. So don't tell me the AF is bypassing the engine and just exiting out the exhaust.
And I'm not overheating the engine or burning up my impeller in the process either.
I have the proper thermostat installed and it's working as expected.

I will also say that when removing the blue plugs, water pours out with great strength and every time I try probing the holes for scale, little, if any scale comes out.

Again, no disrespect, but I've been doing it this way for 9 years.

My 2 cents.
Beat me up if you want, but my almost 20 year old engine is in pristine condition.

 

[QBhoy]

I run -100 degree AF through the engine as an added protection for both freeze protection and anti corrosion. It also helps me sleep without worry through the long cold winters hear in PA.

I may be wrong, but the way I look at it is if there's any water trapped in corners of the engine after draining, it may freeze. Such little water will probably not cause damage, but I just feel better knowing the AF is there.

Plus, I know for a fact that after completely draining the engine, manifolds, etc, there's always water remaining in the intake manifold of my 4.3 Mercruiser. I've seen it through the thermostat housing when replacing the thermostat after draining.

I do understand that "air don't freeze ". That's why I completely drain everything afterwards. So, the AF is just a precaution, maybe the best of both worlds.

I do pull the AF through the outdrive and no disrespect to the experts here, but when I pull the 5 drain plugs, AF pours out of every single one. So don't tell me the AF is bypassing the engine and just exiting out the exhaust.
And I'm not overheating the engine or burning up my impeller in the process either.
I have the proper thermostat installed and it's working as expected.

I will also say that when removing the blue plugs, water pours out with great strength and every time I try probing the holes for scale, little, if any scale comes out.

Again, no disrespect, but I've been doing it this way for 9 years.

My 2 cents.
Beat me up if you want, but my almost 20 year old engine is in pristine condition.

All I was saying is that it’s better and safer to just fill it will AF at the hoses. 100% sure thing then. After drains of course. Why take the risk ?

 

[Baylinerchuck]

I do understand that "air don't freeze ". That's why I completely drain everything afterwards. So, the AF is just a precaution, maybe the best of both worlds.


I will also say that when removing the blue plugs, water pours out with great strength and every time I try probing the holes for scale, little, if any scale comes out.

The poking happens on the block and manifold plugs, not the elbows. I follow the method Scott posted verbatim. Pretty much taken right out of the Mercruiser manual.

 

[poconojoe]

All I was saying is that it’s better and safer to just fill it will AF at the hoses. 100% sure thing then. After drains of course. Why take the risk ?

I understand pouring the AF into the big hoses to get it into the exhaust.

Wouldn't I have to remove the thermostat to get the AF into the block (through the intake manifold)?

I would guess draining all the water first, then put the drain plugs back in, then filling with AF and drain again so air don't freeze. Correct? Or no?