Winterizing inboard outboard

[midnightrider1818]

I was wondering if I leave the thermostat in and suck antifreeze through and the thermostat closes does the antifreeze just not get into the risers. Could I just unhook those hoses and pour a freeze in the hoses so I know I got it in the risers. I guess I'm trying to ask if the thermostat is closed where dont the water or antifreeze make it too.

 

[Bt Doctur]

I was wondering if I leave the thermostat in and suck antifreeze through

Without draining everything first ,its the fastest way to a new engine. Water or AF must exit the motor when its running to cool the rubber components so you will see something no matter how open or closed the T stat is.
Just as easy to drain everything first and pour the AF in.

 

[tpenfield]

depending on your exact cooling setup, the risers may actually get most of the antifreeze, and the engine block gets very little.

Also keep in mind that under normal operation of the engine, the raw water coming in does not shut the thermostat (else it would never open, right?) So, with sucking in AF through the outdrive into the engine, the t-stat is not going to close either, if the engine has been warmed up.

Some of the AF will go into the engine and mix with the water that is there and some will go straight to the risers. The problem being you will not know if you got a sufficient amount of AF into the engine. That is why Bt said to drain the block (and manifolds first), then there is no water in the engine to dilute the AF.

 

[Scott Danforth]

if you try do suck up AF without draining, you will be asking about block and head replacement come spring.

you have to drain the block, manifolds, hoses, etc. then you are winterized. after that if adding AF makes you warm and fuzzy, add it with a funnel as per the manual.