overheat mercruiser

[knot a clue]

i have a 85 welcraft 5.7 mercruiser with gen2 outdrive i have been replacing impeller every year because of overheat it run good all year but when i try to winterize it burns out the impeller my question is can i install electric pickup pump like a wash down pump to put in place of the impeller pump as long as i have enough water pressure so i can eliminate the impeller so i don't have to tear the outdrive apart every year any ever tried this before

 

[Scott Danforth]

No. Your raw water pump moves 20 GPM at 20 PSI. There isnt an electric wash down pump large enough



What are you doing that is burning your impeller? Are you trying to suck from a bucket or something else? Always use muffs unless the bucket is big enough the whole boat sits in it and the drive is fully submerged

 

[knot a clue]

No. Your raw water pump moves 20 GPM at 20 PSI. There isnt an electric wash down pump large enough



What are you doing that is burning your impeller? Are you trying to suck from a bucket or something else? Always use muffs unless the bucket is big enough the whole boat sits in it and the drive is fully submerged

well i have a 6gallon bucket and a hose that goes to the muffs im not sure but i think my hose may be to small i have used this before with no problem i have the bucket on the swim platform so i can keep an eye on the antifreeze but as soon as i started the boat and the antifreeze didn't go down as fast as it should i knew the impeller was burnt so that why im trying to think of a way to bypass the impeller but thanks for your reply

 

[Bondo]

Ayuh,..... You need to start a siphon from the bucket, to the muffs for that to work,.......

Air don't freeze,.....
Drain All the water from the motor, 'n drive, then skip the antifreeze,....

That's what I do,.....

 

[Scott Danforth]

well i have a 6gallon bucket and a hose that goes to the muffs im not sure but i think my hose may be to small i have used this before with no problem i have the bucket on the swim platform so i can keep an eye on the antifreeze but as soon as i started the boat and the antifreeze didn't go down as fast as it should i knew the impeller was burnt so that why im trying to think of a way to bypass the impeller but thanks for your reply

You are burning up your impeller with your process and you are risking freeze damage

The factory manual clearly states
Change oil/filter
Drain all water (pull plugs and hoses).
Then if you want to add anti-freeze, use a funnel and fill from the thermostat housing

 

[crazy charlie]

well i have a 6gallon bucket and a hose that goes to the muffs im not sure but i think my hose may be to small i have used this before with no problem i have the bucket on the swim platform so i can keep an eye on the antifreeze but as soon as i started the boat and the antifreeze didn't go down as fast as it should i knew the impeller was burnt so that why im trying to think of a way to bypass the impeller but thanks for your reply

If this is you choice of winterizing you need to get a Camco kit.As Bondo stated,you need to get a siphon started .This is exactly what a Camco kit will do.It basically runs your motor on muffs with hose water and you later switch over to AF with a simple valve switch over from water to AF.I have done this method for over 30 years and no issues what so ever.Charlie

 

[poconojoe]

If this is you choice of winterizing you need to get a Camco kit.As Bondo stated,you need to get a siphon started .This is exactly what a Camco kit will do.It basically runs your motor on muffs with hose water and you later switch over to AF with a simple valve switch over from water to AF.I have done this method for over 30 years and no issues what so ever.Charlie

Or, you can make your own.
A bucket with a bulkhead fitting, clear hose (for viewing) with a garden hose fitting on the end.
Then a wye hose that has two valves ( used for some washing machines).

Your garden hose connects to the wye along with your bucket filled with AF and the single end is connected to your muffs.

Run on the garden hose, switch valves to run on AF.

I only do this as extra insurance in case there's plain water trapped somewhere. I know it's probably not necessary because air don't freeze, as they say, but for some reason it helps me sleep better.

Then I drain everything and leave my blue drain plugs out for the winter. I put them in a zip lock bag taped to the steering wheel along with my garboard drain plug.

 

[Lou C]

Or you can manually drain, poke all the holes, then pour AF in via the hoses.

 

[Scott Danforth]

Or, you can make your own.
A bucket with a bulkhead fitting, clear hose (for viewing) with a garden hose fitting on the end.
Then a wye hose that has two valves ( used for some washing machines).

Your garden hose connects to the wye along with your bucket filled with AF and the single end is connected to your muffs.

Run on the garden hose, switch valves to run on AF.

I only do this as extra insurance in case there's plain water trapped somewhere. I know it's probably not necessary because air don't freeze, as they say, but for some reason it helps me sleep better.

Then I drain everything and leave my blue drain plugs out for the winter. I put them in a zip lock bag taped to the steering wheel along with my garboard drain plug.

if you dont drain all the water first. switching to anti-freeze does nothing but run out the exhaust as the thermostat wont open when on a hose

 

[Lou C]

Its risky because with no load on the engine you really don't know for sure how far the 'stat opened, if at all. In fact one year I tried an experiment. I had AF in the engine after winterizing it. In the spring I ran it up on the water hose for 20 min. Then pulled the block drains to see what came out, water or AF....well....the AF poured in months earlier, was still in there even after running it for 20 min. So just be aware of that....the stat functions as a gate valve letting water out of the engine, only when it gets hot enough to make the stat open. Sometimes you can tell because the big hose from the stat housing to the circulating pump gets hot, or the hoses that feed the manifolds will get warmer than when you first started it because now the hot water leaving the block is exiting via the stat and mixing with the cool water being pumped in by the impeller...
The only way I'd use the suck up the AF method, is if you drained it before, or, if the engine had a heat exchanger on it and you just wanted to get AF in the raw water side.

 

[ROY WILLIAMS]

you have to use the water hose muff on the lower outdrive flush it out ... then drain the engine water ports , then pour in the engine antifreeze coolant drain ports ... use a turkey baster https://www.amazon.com/dp/B09FKX5VZ...aWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl&th=1

 

[ROY WILLIAMS]

I did the water muff on the outdrive ...cranked it 3 times no start ,then engine runs with idle RPM .......
in todays world the CCP impeller is a breakdown .. post your impeller ..
most replace it 1-2 yrs ...

 

[poconojoe]

if you dont drain all the water first. switching to anti-freeze does nothing but run out the exhaust as the thermostat wont open when on a hose

Really? There's no way the thermostat will open on muffs? If it's idling and gets hot enough, it will open, no?

I respect your statement and knowledge.
You know way more than me by far.

But, once after performing my "procedure", I pulled the thermostat to replace it. I wanted to change it for no particular reason, just to change it.
I looked into the intake and could see the pink AF in there.
Doesn't that mean that the thermostat opened and allowed the AF in? Or am I wrong?

 

[Scott Danforth]

Really? There's no way the thermostat will open on muffs? If it's idling and gets hot enough, it will open, no?

I respect your statement and knowledge.
You know way more than me by far.


Doesn't that mean that the thermostat opened and allowed the AF in? Or am I wrong?

No,. It won't open unless you idle for at least 45 minutes. And then it will only open partially for a few seconds

And unless the Af was at least 180-200 degrees the thermostat would slam shut immediately and any further AF would simply go out the exhaust

 

[Lou C]

Anyone who tries to winterize their boat that way....should take a sample from the block drains, and put it in a freezer set at zero*F and see what happens, that will tell you what's really happening (or use an appropriate antifreeze tester like the one in the pic I posted that can be used with PG antifreezes0....

 

[Drcoffee]

You have watched the wrong youtube video. That might work on an outboard but the engine holds at least 2 gallons of AF after the block is drained. No way you can wash out the water with a bucket of AF via the outdrive.

 

[Lou C]

Really? There's no way the thermostat will open on muffs? If it's idling and gets hot enough, it will open, no?

I respect your statement and knowledge.
You know way more than me by far.

But, once after performing my "procedure", I pulled the thermostat to replace it. I wanted to change it for no particular reason, just to change it.
I looked into the intake and could see the pink AF in there.
Doesn't that mean that the thermostat opened and allowed the AF in? Or am I wrong?

If you didn’t test the AF concentration you would never know how MUCH actually got in. Cast iron Marine engines warm up very slowly at idle in my experience.

 

[QBhoy]

Strongly recommend that you ditch the YouTube method and do what most in the know do…just fill with antifreeze at the thermostat pipe work. After draining of course

 

[poconojoe]

Water seems to remain in the intake manifold, even after draining everything. (2003 4.3L Mercruiser with 5 drain plugs)

So, I should pull the hoses at the thermostat and pour AF down there instead of sucking the AF through the drive with muffs.

Don't I have to pull the thermostat in order to get AF into the intake manifold?

I've been sucking the AF through the muffs for 9 years, then draining. I guess I've been lucky?

I pull the 5 drain plugs, probe the holes and leave the plugs out for the winter.

 

[QBhoy]

Water seems to remain in the intake manifold, even after draining everything. (2003 4.3L Mercruiser with 5 drain plugs)

So, I should pull the hoses at the thermostat and pour AF down there instead of sucking the AF through the drive with muffs.

Don't I have to pull the thermostat in order to get AF into the intake manifold?

I've been sucking the AF through the muffs for 9 years, then draining. I guess I've been lucky?

I pull the 5 drain plugs, probe the holes and leave the plugs out for the winter.

Personal preference, but far and away the most risk comes from taking it from the muffs.
I drain and make sure it’s drained. Put back together. Fill big hose off t stat until it comes back out the housing. Then do the two hoses to the manifolds until it comes out the back.