Winterizing 3055

[ad_rex]

I'm sure this is here somewhere but I have not been able to find. Looking for suggestions/guidance in winterizing twin 5.0 engines in my 3055. This is my first I/O as previous boats have been inboard with a closed cooling system any feedback is helpful and appreciated.

[Nauti_Mike]

I take it you don’t have closed cooling? Did you look it up in the Mercruiser manual?

basic list; flush engine with fresh water, change engine oil and filter, change gear lube. Options drain cooling system and done, flush cooling system with antifreeze and done, drain and flush cooling system and done.

Note you still have freshwater system, AC, and waste lines to winterize.

[vogs77]

A/C is easy, just disconnect the line from the seacock but make sure it is closed if you are still in the water, then put a funnel in the line and fill with coolant, turn the A/C is on and have someone watch to make sure the antifreeze comes out the front of the boat.

I winterize my engines by first draining all the water out of the block, manifolds, and the plug under the water pump. After it is all empty put the plugs back in. Next I use suck in about 2.5 gallons of antifreeze in through the muffs when I start the engine cold, because the thermostat is closed this will fill the supply lines, water pump, and manifolds with antifreeze. The block is still empty so now I pull the large line off of the thermostat housing and pour about 2 gallons into the hose until it comes out the top of the motor, block is now full of antifreeze, done.

You will get some other suggestions but this works for me.

[2850Bounty]

Next I use suck in about 2.5 gallons of antifreeze in through the muffs when I start the engine cold, because the thermostat is closed this will fill the supply lines, water pump, and manifolds with antifreeze. The block is still empty so now I pull the large line off of the thermostat housing and pour about 2 gallons into the hose until it comes out the top of the motor, block is now full of antifreeze, done.

Use caution if/when considering using one the Camco, Star-Brite, West Moron, etc, anti-freeze kits on a Raw Water cooled engine.
Please read this:

https://www.amazon.com/gp/customer-r...at_pdctrvw_srp

[vogs77]

I have read that before too Rick, I know the T-stat is closed and it is just going out the exhaust that is why I run it to fill the supply lines and manifolds and just fill the empty block with coolant after I run the engine for a short period.

[2850Bounty]

I wrote that write-up just about 7 years ago after having read several forum threads whereby people thought that the "kits" worked and that they had actually protected their engine from freeze damage!
Later that spring, they discovered a cracked block and/or cracked heads.
I wrote it in hopes of better explaining the Raw Water cooling system and the use of those kits.

When we drain it again afterwards, we don't need to worry about dilution.

[ad_rex]

Thanks to all for advice.

[JimMc]

Send me your email to me in a private message and I will send you the full process I use for my 305.