Logo
FULL SITE MENU

Draining water from engine block and exhaust manifolds

L

LakeErieFishing

Member
To drain the water entirely from the engine block and logs/risers, can I just remove the petcocks from the engine block or do I also have to detach the hoses for everything to drain?

Thanks
 
To drain a motor:
Remove the block drains and probe to make sure they do in fact drain
To drain manifolds:
Remove hoses at the bottom of the manifolds or remove the drain plugs to drain manifolds/and/or risers
Should you desire to fill the motor, simply pour AF into the manifold hoses untill it comes out the exaust. For the motor remove the large hose from the therm housing side and pour AF into the block untill it comes out the therm housing
 
To add to what BT said.

You have a incoming water hose, it comes from the transom area on the drivers side of boat. It goes to the thermostat housing.
This is the incoming water supply to engine from outdrive.

Remove the hose from thermostat housing, fill hose with RV antifreeze until it leaks out of the outdrive which should be in the down position.
This back flushes the incoming water hose, Power steering cooler and makes sure no residual water is left in that part of the water system.

It takes time and you will have to add small amounts RV antifreeze at a time several times to get the pressure to push the water back out.


I would also remove all the small hoses at the thermostat and fill each with RV antifreeze to make sure it gets into every nook and cranny. Just a precaution.

As BT said, the very Large hose at from of motor that goes from motor mounted water pump to thermostat housing,
Remove from thermostat housing and bend down to dump any water in it, then after block plugs (both sides of engine near oil pan area approx center of block) have been removed, and all water has drained, put plugs back in and then fill RV antifreeze into large hose and this will fill block. Use about one gallon.

In total you should only need 2 gallons of RV antifreeze but it is cheap and use what you feel you need. It is just a bit of insurance if you missed any small amounts of water.
 
kghost said:
To add to what BT said.

You have a incoming water hose, it comes from the transom area on the drivers side of boat. It goes to the thermostat housing.
This is the incoming water supply to engine from outdrive.

Remove the hose from thermostat housing, fill hose with RV antifreeze until it leaks out of the outdrive which should be in the down position.
This back flushes the incoming water hose, Power steering cooler and makes sure no residual water is left in that part of the water system.

It takes time and you will have to add small amounts RV antifreeze at a time several times to get the pressure to push the water back out.


I would also remove all the small hoses at the thermostat and fill each with RV antifreeze to make sure it gets into every nook and cranny. Just a precaution.

As BT said, the very Large hose at from of motor that goes from motor mounted water pump to thermostat housing,
Remove from thermostat housing and bend down to dump any water in it, then after block plugs (both sides of engine near oil pan area approx center of block) have been removed, and all water has drained, put plugs back in and then fill RV antifreeze into large hose and this will fill block. Use about one gallon.

In total you should only need 2 gallons of RV antifreeze but it is cheap and use what you feel you need. It is just a bit of insurance if you missed any small amounts of water.
Click to expand...

Thanks all. So filling the engine block through the large hose (which attaches to the base of the water circulating pump) will fill the block AND the upper manifold (what the thermostat attaches to and carb sits on)? Or will I also need to pour some antifreeze into that area through the thermostat?
 
Mr. LakeErieFishing, no offense to you....... your questions indicate that you may have limitted mechanical experience.

For someone with limitted mechanical skills, you will want to know that any residual seawater (in the Engine or Exhaust) may cause dilution to the anti-freeze. If that was to occur, your freeze protection has now become sacrificed if you plan to leave the antifreeze installed.

Keep in mind that just plain ole AIR will not freeze expand and crack your expensive cast iron components......... whereas accidental dilution of the Anti-Freeze may pose a risk that could be very costly!


I would suggest that you drain every low point on your Engine's cooling system, including the Engine Circulation Pump, and drain every low point of the Exhaust system.... and then leave it alone!

The rust that will occur during the winter lay-up is extremely minimal compared to what occurs during the boating season.


If Hell Bent on doing the Anti-Freeze thing...... at least drain it again after installing it.
That way you will have avoided any dilution potential.


Just for fun, take a few minutes and read this article!


.
 
Last edited:
kghost said:
No need to read any article.
The advice given is proven by professionals.

Enough said.
Click to expand...

Professionals...... Yes!

Please read the article!
Numerous DIY'rs make this mistake each and every winter.





Docksidemarineservices said:
My advise is to have a competent established Marine Mechanic winterize your boat for you. Best $200 Labor charge you will ever spend.
Click to expand...

I'll second that!


.
 
Last edited:
Docksidemarineservices said:
When it comes to business and marine repairs, I have no friends.....LOL
Click to expand...


I mostly do friends boats these days.

Have a regular corporate job...mon-fri.

it just so happens I have 12 or so friends and their families all have boats so I do get a lot of work......

I only get a few "customers" these days as I don't seek them out anymore......
 
Docksidemarineservices said:
When it comes to business and marine repairs, I have no friends.....LOL
Click to expand...

Chris, that is the difference between "Professional" and "Non-Professional".
People like you and I have earned an income doing Marine Repair.
I'm not sure that recieving beer for payment qualifies one as being a "Professional"! :eek:


Mr. LakeErieFishing, I do wish you the best of luck! None of us want to hear about a cracked cylinder block or exhaust component come next Spring time!


.
 
RicardoMarine said:
Chris, that is the difference between "Professional" and "Non-Professional".
People like you and I have earned an income doing Marine Repair.
I'm not sure that recieving beer for payment qualifies one as being a "Professional"! :eek:


Mr. LakeErieFishing, I do wish you the best of luck! None of us want to hear about a cracked cylinder block or exhaust component come next Spring time!


.
Click to expand...

I guarantee I have many more years and boats under my belt as a professional then you think.

Because I do not do it now for a living any longer does not make my expertise any less....

I also guarantee my professional credentials are far superior to yours!!

Enough said!
 
Mechanics who have undergone professional training typically call an Engine an Engine..... not a motor.
If you'll notice, we are on the MarineEngine.com forum........ not MarineMotor.com !

Also, those with great credentials would NOT suggest to a DIY'r that he winterize his Engine by adding antifreeze that could potentially become diluted......... at least not without recommending that he drain again afterwards.


Yes...... I agree...... Enough said!


.
 
Last edited:
You should poke out all of your drain holes to dislodge any rust flakes or sediment that may be blocking them to make sure you completely drain before adding the a freeze.
 
If just draining remember not just the block drain plugs (make sure to poke them) but also disconnect the bottom end of the big hose that goes from the front circulating pump to the Thermo housing, that holds a lot of water in addition to what comes out of the block drains.
 
Back
Top