Mercruiser 4.3tks overheat on muffs

[kaclark22]

Hi all - i winderized my boat yesterday with one of those 5 gal diy jugs that connects to the earmuffs. I was struggling to get a good flow of antifreeze out of that thing (yes, the vent cap was open). You don’t get much pressure with this thing either unless you can find a way to keep it up higher. My only option was swim platform and tilting the tank. I think i should have cut down the hose so it wasn’t so winding. Anyway, live and learn.

Towards the end of the 5 gallons i ran through i noticed too much smoke coming out of the exhaust. When i checked my tstat gauge i was just south of 225F. Normal operating temp is 175F. No alarm went off and it only ran hot for a few seconds until i could get to it. I have a 2016 sea ray spx boat with the 4.3tks (carbeurated).

my questions:
1. Why no alarm? Wouldn’t you expect it to alarm?
2. Other than the impeller and temp gauge, is there anything i should check or watch out for when i am back on the water in spring?

Thanks!
Kyle

 

[Grub54891]

Your impeller could be bad, but what I do is set up a freshwater pump on the jug, hooked to a jumpbox, turn on pump, start motor. It forces the anti through the system. Hope you didn't hurt the impeller or the exhaust flappers or other rubber components.

 

[alldodge]

1. Why no alarm? Wouldn’t you expect it to alarm?

At 225 degrees it should have gone off, unless the temp switch needs replacing, or could be your temp gauge is not accurate

2. Other than the impeller and temp gauge, is there anything i should check or watch out for when i am back on the water in spring?

No, other then leaks

I hope you did drain everything before doing the AF

 

[Bt Doctur]

Because without draining everything first there a good chance you will be replacing the motor due to freeze damage
Just as easy to POUR it in and without removing the drive for it`s service your at risk there too,

 

[Lou C]

Raw water cooled engine?
Please do NOT use those stupid lazy-azz tanks! They are not good for a raw water cooled engine, and even on a closed cooled engine, they need a pump to pressurize the flow, gravity is not enough!
More importantly....the thermostat must open all the way for AF to get into the block using these kits, if it does not...then you will have enough water in the block (if you did not drain or remove the 'stat first)….to freeze and crack a perfectly good engine!

You need to do it the right way....
manually drain the engine and manifolds...poke all the drain holes...the engine holds probably 2-3 gallons of liquid...the manifolds prob a half gallon each....
Then disconnect the big hose at the front circulation pump at the bottom end, that drains a lot...
And the raw water intake hose leading to the transom mount...disconnect it at the thermo housing, point it down to drain, and then back fill it with -100 marine AF with your outdrive all the way down, this will flush out the water in the hose that goes through the transom mount....Then just bump the engine with the starter, to make sure that the AF gets into your impeller housing (do not start it, just get it to turn a bit).

Now if you want to use AF to reduce corrosion damage..(suggested by Merc in their own manuals) you can:
Fill each manifold till it runs out the exhaust, via the feed hoses at the thermo housing...
and then re-connect the big hose bottom end at the front circulation pump....disconnect the top end....then fill that hose....till the AF spurts out of the thermo housing neck (no you do not have to remove the thermostat)…..it will take 2-3 gallons or so....and then re-connect the top end of that hose....

Manifolds and engine full of -100 AF, all good. Notice I do not recommend the lesser levels of protection...…(ie -50 or -60) these get hard at about 0-10*F and if there is water left in the engine, can get diluted....the -100 will not....

I tried one of those stupid tanks about 15 years ago....nearly overheated the engine like you...and checked the block drains...dirty water because the thermostat did not open enough....

What I did with it...was hook up a live well pump to it....and use it as a flusher for my drum trailer brakes.....

 

[kaclark22]

Thanks everyone. I will likely replace the impeller in the spring. Easy enough to do.

Lou C - many thanks for your post. By no means do I consider myself an expert but I have owned a boat for 5 years and never had a winterization problem. What i do is run to temp on muffs with water then run 5 gal of -100af through it then pull the block, manifold and power steering cooling plugs and leave them out until Spring. Every plug i pull has antifreeze that comes out. If not, i poke the hole with a screwdriver and then i do. Running the af through muffs fills the outdrive. I don’t understand why I would need to do anything more than this. Do you think i am truely putting myself at risk? I want to make sure i’m fully protected of course but i have survived 5 seasons.

 

[alldodge]

Draining is the key, so long as you have drained everything your good

 

[Lou C]

Ok if you drain that’s fine but the whole point of using AF is to reduce corrosion. It can’t reduce corrosion if you dump it out! In that case you’d be better off manually draining everything; or manually draining and then back filling with AF....

 

[Walt T]

As a professional I will never use those tanks. Just drain it. Air doesn't freeze. Remember, if you have a single point drain system on your Merc, disconnect the hoses from the block after it stops draining and poke a small screwdriver into the block. Many many times I have found those plugged by rust and a block full of water drains.

 

[corvettedude]

So weird, I have winterized my boat for 4 years this same way and today when I done it I had the same problem as you it ran fine on the muffs the tstat was opening at 180 and everything was fine, but at the end it didn't wanna pick up about the last 1/2 gallon outta my 5 gallon jug and she was getting warm. 200 and I shut it down but I think if I would've let it go she would have went more.