Chris288

When running anti-freeze through the sea water pump and heat exchanger for the winter, through the flush muffs, is there any type of warming up needed before the anti-freeze would go through the entire raw water part of the closed cooling system.. thanks..

rotax

hey chris

first blow out any water with the little blue pump then run antifreeze thought
it .
my 525 does not have the pump systems . so i just run 5 gallons throught it
just to make sure its all anti freeze coming out.

great year with the new 288 75.4 hours . 1 more seasion then going bigger

Chris288

Rotax,, thanks for the reply,,, I had a little problem when I winterized, yesterday,, I was able to do everything BUT the anti-freeze, so I trailered the boat home, pumped out the water w/ the air pump, popped off the fuel filter and filled it half way with 2-stroke put it back on hooked up the muffs with a funnel attached and started the boat,, buddy started pouring in the anti-freeze until it started comming out the exhaust tips,, 3 gallons, just like I have done for the last 6 years, and then I pumped the anti-freeze out again.. Now for my original question,, engine was NOT up to temp. because I had to trailer it home. Just wanted to ask the board if the raw water / heat exchanger is an " open " system and that I am protected..

rotax

ok good ..
you could keep the antifreeze in thier it is better for corrosion.
but if you pumped it out after .it should be ok.

time to clean off the skidoos

Sydwayz

iTrader: (1)

I dunno the answer Chris, but I am interested to know as well. I believe the answer is the any thermostat is in the antifreeze/closed cooling portion of the block, not the sea water section of the cooling system. We do need a mechanic to confirm this though.

If you read the book. It states NOTHING about running antifreeze through the motor. My mechanic said to be safe and sure, you should run it through, as their are pockets of sea water still in the system, including the heat exchanger. All the book states is leave the system pressurized with air, and through normaill boat movement though travelling/trailering, it will push excess water out. Umm, where? Umm, do you pull the freeze plugs? Who knows.

I know better, but I wonder if I just follow the 'book' proceedures, and allow my stuff to crack up, if I can get new engines each spring under warranty?

Chris288

Brian,,, I agree when you " pump up " the system,, I would guess a good amount of the water trapped in the raw water portion of the H.O. is evacuated through the drain valve on the bottom of the motor, but like you i'm very anal about everything and want to make 100% sure..

BryanTuvell

I have the shop manual which desribes the winterization procedure, I will try to post it today.
Bryan

Chris288

Can't believe nobody knows if the raw water / heat exchanger part of an H.O. is an open system,, I.E. no type of thermostat.. ??

ccarloss

There is no thermostat in the closed cooling system. The only thermostat is in the engines cooling system.

Just in case you want to verify http://www.mercruiserparts.com/Show_...COOLING+SYSTEM

Reckless32

The heat exchanger is open. It's a simple functioning system that runs raw water over internal tubes that the closed coolant passes thru after running thru the engine block. It functions the same as a radiator on a car, only no fan. Nothing restricts water flow thru the tank, otherwise you would overheat at the risers from lack of water setting off the alarm (guage reading fine BTW). The cooler coolant is cycled thru the tank until the internal coolant heats up at which time the thermostat opens sending the now hot coolant thru the tank to be cooled. Like I said, just like a radiator.

Pump it up and leave it open after a good flush ideally with salt-away, then anti-freeze especially in your geographic area where winters are longer and deep freezes for several days are common.