# Winterizing a YSM8 ?



## gyc (Aug 16, 2020)

I have a Yanmar YSM8 (1 cylinder) that will not start. The boat has been hauled and needs to be winterized. The boat is in upstate NY.
The manual says all I need to do to winterize it is open the water drain cock on the engine. 
Has anyone done this and not had any problems ? Or have done this and had a problem ?
I am a bit skeptical as I always run the engine and run antifreeze until the pink liquid comes out the stern. 

And if anyone has any other suggestions I would greatly appreciate it.
Is there something else I can/need to do to make sure all the water is out of the block ? The boat is fresh water cooled. 

Thank You for any and all help, suggestions, advice !!
Kathleen


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## SchockT (May 21, 2012)

If it is fresh water cooled then the block should have antifreeze in it, and all you are draining is the raw water out of the heat exchanger.

I would expect that the manufacturer knows how to winterize their own engine...

Sent from my SM-G960W using Tapatalk


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## Minnewaska (Feb 21, 2010)

I wonder if there is a chance the OP is stepping on terminology. I don't think that engine came with a heat exchanger and would, therefore, be raw water cooled. I'm sure a conversion kit was available, but then the book instructions may no longer apply. 

In theory, the raw water passages should be able to be drained. However, I'd still prefer to soak in anti-freeze for it's anti-corrosive properties.


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## Ninefingers (Oct 15, 2009)

gyc said:


> I have a Yanmar YSM8 (1 cylinder) that will not start. The boat has been hauled and needs to be winterized. The boat is in upstate NY.
> The manual says all I need to do to winterize it is open the water drain cock on the engine.
> Has anyone done this and not had any problems ? Or have done this and had a problem ?
> I am a bit skeptical as I always run the engine and run antifreeze until the pink liquid comes out the stern.
> ...


If you have a way to pump antifreeze through a hose, you can pump it through most likely. Mechanics sometimes rig a hose with a plunger on the bottom and blast antifreeze through the thru hull that way.


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## lillia28 (Aug 12, 2011)

The YSM 8 is raw water cooled. 
The trick to winterizing is to remove the thermostat to make sure the anti freeze gets to all the passages. So open the drain plug, pour AF through the T stat housing until you see AF coming out the drain. close the drain plug. Fill the engine with AF. Treat the T-stat carefully, the raw water type are very expensive, they open at a lower temperature (140?) and are not interchangeable with the fresh water type. Make sure you note which way it sits for spring time. If installed the wrong way it will never open, so overheated engine.
If you have a water lift muffler, don't forget to winterize that.
Lou


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