Winterizing 1992 mercruiser 3.0 antifreeze

[Hag]

Well got this new used boat. My first I/o, (I have about 16 outboards I rebuilt) and need some guidance on winterizing. I'll change the lower unit oil, will change lower unit impeller, will change motor oil. Will fog carb and cylinders.
I'm thinking about changing the water pump on the engine. Should I? If I do I'll change the single belt but have to remove one of the engine supports to get belt off and on. Is there any trick like needing to support the engine?
I did drain the block- 2 brass drain plugs port side rear on engine. Are there any more?
I did change the thermostat (looked like not changed from 25 years-that's why I think I have to change water pump too).
Do I leave engine empty or do I fill with antifreeze over winter? Any kind of antifreeze? 50/50 cheap auto kind or special?

Thanks for any help you can give.

 

[thumpar]

No need to change the circ pump unless it fails, which is rare normally. Leave the engine empty but you should have a drain on the exhast. Also pull the big hose on the water pump to get any extra water out. There is no need for antifreeze.

 

[Hag]

Ok don't change pump, it was working a few days ago no overheating.
Ok leave engine empty.

You said another drain on exhaust? Where?

About the engine mount to change belt , there are 3 supports in the front of engine, would have to take out the port side. Do I have to support it or will the other two support it. To change the belt which looks pretty old too.

 

[Alumarine]

There's a drain on the port side of the exhaust elbow.
No need to support the engine if you just remove the block on the port side.
Also, wrap an extra belt behind it as well to make changing the next one easier.

 

[Hag]

Ok thanks for the location and the extra belt is a smart move thanks.

 

[Starcraft5834]

agreed, leave it empty,, main block petcock plug, right side rear, manifold drain, same side above that... remember to put your plugs back in when empty, leave transom drain plug out.

 

[Hag]

ok thanks.
you know looking inside (via the hose or when i changed the thermostat) i see a lot of rust build up. Is this a big issue? Should i do anything about it? What? Again did not overheat but i see a lot of rust. Was only used in fresh water.

 

[Bondo]

Ayuh,.... Rust, sand, 'n other crud is normal, don't worry 'bout it, Except at the drains,....

Poke, 'n prod the drain holes with a nail or screw to make sure the water drained out, then put the drain plugs back in,....

I too, store 'em Dry,.... Air don't freeze, ever,....

 

[Hag]

ok thanks for the input. btw air does, it feels like, try to freeze sometimes here in upstate ny but........

 

[Bondo]

ok thanks for the input. btw air does, it feels like, try to freeze sometimes here in upstate ny but........

Ayuh,.... Even at -40?, it's still breatheable,...

Year before last, we had a week that it never got up to 0?, 'n the nights were -35? to -40?,...

No frozen busted blocks in the fleet that I maintain,....

 

[shaw520]

it is a fact that air doesn't freeze,... but some would argue that metal surfaces left exposed to air will corrode faster than surfaces submerged in anti freeze......

 

[thumpar]

If you ware worried about corrosion don't put your boat in water. When is the last time you heard of a block rusting through?

 

[shaw520]

If you ware worried about corrosion don't put your boat in water.

....now there's a helpful tip,... thank you for that!

Any steps towards reducing rust and scaling on the internals of engine blocks and manifolds in my book is a good thing, and yes, I have seen manifolds rust through.

 

[thumpar]

....now there's a helpful tip,... thank you for that!

Any steps towards reducing rust and scaling on the internals of engine blocks and manifolds in my book is a good thing, and yes, I have seen manifolds rust through.

I wrote block. Manifolds.risers will rust through with or without antifreeze. The type of water will you boat in will let you know the timeline. A lot of the AF out there doesn't even have corrosion protectents.