Single point drain winterization

[Mcfltfyter]

I have a 2006 5.0mpi and this is my first boat. I need to winterize it for a week or so, so I used the single point drain. When i checked the block drains, both hoses were 100% packed with dirt along with the block ports. What other drains are likely to be plugged? I was planning to have all summer to learn the cooling system on a boat and remove the single point drain entirely if possible.

What else do I check for now?

 

[Bondo]

Ayuh,..... Welcome Aboard,......
Both block drains, each exhaust manifold, pull the big hose off the circulating water pump, 'n the P/S cooler in the in-coming water line from the drive,.....
Removin' the single point drain system is a very smart move,.....

 

[Mcfltfyter]

The manifolds have a tee that goes to the single point drain, so I would pull the other line I assume? The circulating pump is pretty obvious, but i could use more info on the the power steering cooler.

 

[Mcfltfyter]

I'm assuming the p/s cooler is port side down deep with a 1.5" hose. Do I need to pull the stern side or can it be disconnected at the single point drain side?

 

[Bondo]

I'm assuming the p/s cooler is port side down deep with a 1.5" hose. Do I need to pull the stern side or can it be disconnected at the single point drain side?

Ayuh,..... Pull the big hose off, on whichever side is the easiest, 'n will allow it to drain,....
Usually, the under-motor mount, don't matter which end ya pull,....

 

[Scott Danforth]

in addition to the two block lines being plugged, those hoses run to a spider manifold on both the single point and a 3-point drain system.

I do suggest yanking that whole mass of hoses.

 

[Mcfltfyter]

in addition to the two block lines being plugged, those hoses run to a spider manifold on both the single point and a 3-point drain system.

I do suggest yanking that whole mass of hoses.

What do you mean by "yanking that whole mass of hoses?" You mean R&R to winterize?

 

[Scott Danforth]

No, pull the 50 pounds of extra hoses and fitting and plastic and go to simple drain plugs

 

[Lou C]

It’s amazing the lengths Mercruiser went through to avoid making closed cooling standard and in that process overcomplicated a previously simple raw water cooling system to a point that is almost unbelievable. Take a look at a recent Merc parts diagram and see how many hoses, plastic couplings, fittings etc they have added. Whereas an old OMC or Volvo raw water system has:
One hose coming from the transom mount to either the stat housing (OMC) or impeller housing (Volvo), and one hose each from the stat housing to each manifold. Then there’s the large hose from the thermostat housing to the front circulating pump that they all have.
So what has Mercruiser accomplished?
Nothing, IMO
Even a full closed cooling system is SIMPLER than this nightmarish Rube Goldberg piece of trash Merc has pushed on their unsuspecting customers

 

[Mcfltfyter]

Baby steps my friend. I have only a general idea how the cooling system on a boat works.
The block drains are easy, but I wonder if I couldn't just plug the hose and use the quick connects and not worry about chasing threads for a pipe plug.
It sounds like I could just get 90's for the manifolds that have a blue plug.
I'm not sure what the upper lines to the manifolds are, or what do do with them. I'm guessing they are supply from the drive?
The y on the circulating pump is supply to the engine?

So much to learn, but at least I know nothing will spit for now

 

[Mcfltfyter]

What engine would I look at for a schematic of no single/3 point drain?

 

[Lou C]

I’m not sure what year they started with this but look at any on line Merc catalog start about 2000 or so if that has it then go back a few years.

 

[QBhoy]

You could of course just make sure each section is draining, by un doing each quick connect fitting at each source. That’s what I do on my single point mpi. Never found it blocked though. It’s always been left full of antifreeze in winter lay up...so doesn’t corrode the inners and cause it to block up with debris

 

[Stinnett21]

You could of course just make sure each section is draining, by un doing each quick connect fitting at each source. That’s what I do on my single point mpi. Never found it blocked though. It’s always been left full of antifreeze in winter lay up...so doesn’t corrode the inners and cause it to block up with debris

This is what I do also. I've owned this system new since 2002. I pull the quick disconnects on each side of the block and poke the holes. Some years I will pull a few hoses and poke them also. Never found a block. Now to be fair I'm 100% fresh water.

 

[Lou C]

This is what I do also. I've owned this system new since 2002. I pull the quick disconnects on each side of the block and poke the holes. Some years I will pull a few hoses and poke them also. Never found a block. Now to be fair I'm 100% fresh water.

I think it can work in freshwater, but in salt? More often than not I've had to poke the old fashioned drains with a pick or small screwdriver on mine to get them to drain.
Just for reference you should be getting almost 5 gallons of liquid, maybe a bit more from a full drain. That's how much antifreeze it takes to fill up my 4.3+ the exhaust manifolds after I drain it.

 

[Lou C]

STANDARD COOLING SYSTEM(DESIGN I) - 1990 Mercruiser 5.0L [ALPHA] 450B100CS | Crowley Marine
Here's a pic of what their cooling system used to look like before they "improved" it.
About the same number of hoses as an OMC Cobra or Volvo Penta SX and conventional drains.

 

[Bt Doctur]

Remove the hoses and fittings in the block and install removable drain plugs. Remove the manifold drains and hose and install ones with removable blue plugs to drain the manifold. At the pipe where the hoses come together just loop the hoses or remove the pipe manifold and replace w copper tubing

 

[Bt Doctur]

 

[Bt Doctur]

These accept the blue winged plugs

 

[Mcfltfyter]

I will add the blue plugs to the block and manifolds. I'm thinking it would be easiest to remove the single point valve and replace it with a manifold with a drain plug.