Can mercuriser drain system be trusted

[andrewterri]

We just got of first slip at the marina and put the boat in it today. The forecast looked good and now the low for tomorrow night is showing to be 36 degrees. That is way to close to risk water being in the engine. My choice is to have me wife drive the trailer to the other side of the lake to load or drain the engine using the mercruiser drain system. Can I trust the drain system? I have seen many posts saying it is not any good. What do you guys think? If I cant trust the drain system I can fight the wind and get it loaded and brought to the house tomorrow where it will be in a heated garage.

 

[Bt Doctur]

Unless you remove the quick connects at the block to insure there open to drain there`s no way to know if the single or 3 point drain system will do its job. I personally remove them from my customers boats
And when your plastic water dist housing (it`s plastic) cracks ,I have a copper fix for that too.

 

[andrewterri]

I did not know there were quick connects. Where are the located? I have drained it even through it has been in the garage until know and I just turned the blue handle then removed both blue plugs.

 

[Bt Doctur]

bottom block #18 one on each side of the block just above the oil pan
http://www.mercruiserparts.com/Merc/...MMON/31661.gif

 

[andrewterri]

awesome thank you. do those quick connects attach to anything. the picture does not show what they connect too.

 

[Bondo]

We just got of first slip at the marina and put the boat in it today. The forecast looked good and now the low for tomorrow night is showing to be 36 degrees. That is way to close to risk water being in the engine.

Ayuh,..... While I'm not against drainin' yer motor, the risk is quite low,.....

The hull acts as a heat sink, the water it sits in, is well above freezin',....

The quick-connects have a hose on 1 side, 'n the block on the other,.....

 

[Scott Danforth]

in addition to what Bondo stated, if your that concerned, put a trouble light under the engine hatch next to the motor. it willl keep the motor about 50 degrees.

 

[Alumarine]

Just to be clear. You can drain the block while the boat is in the water.
You do not have to take the boat out of the water.

As Bondo said with it being in the water there is less chance of freezing.
Nothing wrong with draining it though.

 

[Cortes100]

FWIW, my last boat was a 2008 Searay with a 3.0L and the single point drain system. I used it for 8 years and never had any problems. One hose for block and one for manifold. I would lower one hose at a time and watch the water drain out. Sort of a no brainer, if no water came out, then I would suspect it was plugged, but that never happened. Winterizing, I would pour in antifreeze till it ran out the hose.
Now if you have a system that has multiple hoses going into one outlet, well then it would be tough to tell if all hoses were draining.

 

[Bt Doctur]

Yes, the 3.0 is easier to see with only 2 hoses but the single point has the manifolds with check valves and the block with quick connects. With most engines over time the block drains get plugged with rust and sediment. So unless you probe the hole you can not tell if it is draining. A typical gm v8 will drain about 4 gallons of water with a single drain system.
I explain this to my customers if they decide to do their own winterizing. It is why I remove this system from my customers boats.Nothing is more positive than removing a brass plug and probing the hole to ensure draining.
Easy to check by removing the block quick connect and see what drains out. If nothing comes out, its plugged and did not drain during the draining process .The same with the exaust manifolds, Failure to drain leads to cracked manifolds and most times the crack is internal and that water goes into the exaust posts and cylinders .rusting the bores and maybe a seized engine

 

[Bt Doctur]

 

[QBhoy]

I have the single point drain system. But always disconnect the quick connect fittings on its network just to make sure...then re connect.
A word of warning though...if your boat is in the water and anything like mine...if you leave the valve open...you will find it won’t stop draining, haha. It is below the water intake level from the drive on mine.
Generally if the water the boat sits in isn’t freezing, the temperature from the water conducts to the water in the engine. If you still seeing freezing, I would Defo be filling with strong anti freeze though through the hoses at the t stat and into the exhausts and risers too. You will sleep better.

 

[andrewterri]

Thank you guys for all your help. I had no idea this engine had the quick connects. I have learned a lot the last couple days, some things the hard way. If you didn't see my other post I was able to get the boat out of the slip. I am keeping it in the garage until the lake level raises and the water temp warms up. I will just use the slip for the kids to go fishing in. The marina said the crappie will start running in a couple weeks and the cove the marina is in is a popular spawning area.

 

[Lou C]

I have a set of pics in a plastic bag that I keep on the boat, I use these to rod out the drains. All the engineering that Merc put into these foolish systems could have gone into standard closed cooling, making the engine last longer and be easier to drain. Yes the heat exchanger adds cost but it also adds years of life. For Shame! GM intended their cast iron engines to have clean antifreeze with corrosion inhibitors and a pressurized cooling system! Not filthy raw water and an open system. Fine for self draining outboards, not for inboards!

 

[andrewterri]

I have several sets of cleaning rods I use for our seadoo carb's when I rebuild them. I will keep an extra set on the boat. We plan on getting a new boat that is a little larger in a couple years and after reading everyone's post it will be a closed cooling engine. I did not realize how big of a deal that closed cooling system is. I am hoping mercruiser's new engine proves reliable.