720 Engine winterization questions.

[JamesHBCA]

I have read a couple threads on winterizing the 720 with plugging the hoses to hold the antifreeze in and have a few questions.

Is it really necessary to keep it filled with antifreeze, that is if you fill it and it drains out, what is left to freeze and ruin the engine?

Can you just blow out the water with compressed air?

What is going to stop the antifreeze from seeping into the engine when it's not running with exhaust pressure to keep it out of the cylinders and crank case the way it does if you run it on the hose and the engine dies?

 

[LouDoo]

Congratulations, first winterization thread of the season. You need to run antifreeze through the engine for a couple of different reasons. Yes you are correct a lot of it will just run out but what is left in the engine will protect the engine and exhaust. Also even if you blow through the engine with compressed air there will always be some water trapped inside the engine and exhaust and water box, the antifreeze will keep this from freezing, you are dealing with an aluminum engine block and cylinders, it doesn't take much to crack these. I don't recommend blowing through the engine with compressed air.

When you winterize your boat be kind to the environment and use RV antifreeze, the added benefit is next spring you can just exhaust the anti freeze into the lake.

There's lots of good information on this site about winterization as well as in your service manual.

Lou

 

[JamesHBCA]

Thanks LouDoo,

Yeah, sorry about being "that guy" but I am headed back to the west coast and leaving the boat in Buffalo so I have to winterize it early. Never had to winterize it before and I don't like the idea of hose pinchers all over the place.

I thought I read somewhere the 720 was self draining? Perhaps it is, but just needs the antifreeze to be on the safe side. It gets dang cold in the winter here! (which is why I not going to be here, lol)