View Full Version : T-stat winterizing question

11-02-2006, 10:38 AM
Hi Guys
So i took my boat out and drained the block at the end of the day on Saturday. I only started to winerize on Sunday morning, and i forgot to allow the engine to get up to temp before sucking in the antifreeze.
I assumed that the antifreeze is throughout the block because it was emptied the night before and there needs to be coolant(water or antifreeze) for the boat to run right? It would have filled up the block on start-up, correct?
Now I did see pink antifreeze coming out of the exhaust.
SHould I do it again?

11-02-2006, 10:48 AM
Always better to be safe...if it were me, I'd do it again - this time after the engine is at operating temp. I'd be worried that the mix was too diluted, especially if there was water in the t-stat housing yet. You mentioned you drained the block...how about the manifolds, and did you pull the hoses off the front of the motor and drain those (raw water pump and circulating pump)? If you did, then maybe you're safe and all the water got out the first time.

11-02-2006, 10:52 AM
Does it also work if you take the termostat out - then you don't have to wait for it to warm up??

11-02-2006, 11:01 AM
Does it also work if you take the termostat out - then you don't have to wait for it to warm up??

Yeah, that's a good option too - forgot about that!:(

11-02-2006, 11:35 AM
Redo.....if the boat wasn't fully up to operating temperature, your going to have problems in the spring. Then again you'll have a new boat then too:D

I'd do it again just to be on the safe side.

11-02-2006, 11:52 AM
If the motor wasnt up to temp then the thermostat hadnt opened. The A/F was sucked in and then pushed right out the exhaust manifolds- and never circulated through the motor.

I would either redo it with the boat up to temp, or remove the thermostat and pour the A/F into the block.

11-02-2006, 11:58 AM
why not just drain the whole thing? manifold, tubs, sleeves, and block...then pour a little antifreeze in the sleeves and crank the egine over slighly...pull the impeller, leave the block plugs open...shake the boat or tow it realy quick...and rest easy? am i wrong?

11-02-2006, 12:01 PM
Typical coolant circulation:

http://mccollister.info/cooling diagram.jpg

Note that the thermostat typically lets water out of the block, not in. Therefore, if the block is drained THEN antifreeze sucked up, you should have antifreeze everwhere in the block.

11-02-2006, 12:38 PM
Open the 2 block drains and see what comes out. If it's pink you're good. If not run a/f through it again.


11-02-2006, 12:46 PM
BIGMAC that's what i was thinking also, but it still makes me nervous.
Now if i opened the drain on the block and A/f came out i should be ok, right?

ERK Yes new boat will be awesome!:D but the new owner of my boat might not be too happy with a frozen block! Plus I really take care of anything I own.

11-02-2006, 12:59 PM
Bigmac, thanks for the pic. I learned something new today.

RHSProstar, if you open a block drain and A/F comes out, then yes you are OK. This would prove Bigmac's point.

11-02-2006, 01:05 PM
How about no anti-freeze? Live in New England, and have never put anti-freeze, pink or otherwise in my 2 Mastercraft. No issues. Just a thought

11-03-2006, 03:12 PM
OK.. SO i drained the block and there was pink A/F in it. I decided not to take any chances and redid the whole process again.
But for future reference if you drain the block, and immediately suck up A/F you will be set to go for the winter as Bigmac said, even without bringing the engine up to temp or removing the t-stat.:D

11-06-2006, 07:52 AM
Does it also work if you take the termostat out - then you don't have to wait for it to warm up??

That's what I've been doing for years. Of course, after I got bit by now having my engine "up to temp enough" for the T-stat to open.

Now, I pull it & know for sure. It's 3 bolts & 1 hose clamp. All of 1 minute to pull, then another to replace.