350 MPI Winterize - Block Drain?

Holt_22

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So new to this engine, it has a Cooling System Flush Port. Can this be used to run Antifreeze into the system until it’s running out of the exhaust?

Or, should I just drain the system with the 6 petcocks?

Attached are some pics of the engine. I could not find the s/n tag... which annoys me.

Thanks for any info or input.
 

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Last edited:

Scott Danforth

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Drain the system, make sure to verify all the drains have drained and are not plugged.
 

Bondo

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Ayuh,...... Welcome Aboard,....... Regardless whether you want to put antifreeze in it, or not,.......
Step #1 is always Drain it dry, first,......
 

tpenfield

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Keep in mind that the flow of water (or antifreeze) through the engine and exhaust is in 'Parallel', so the pink antifreeze will show up in the exhaust before the antifreeze has fully gotten to and through the engine.
 

Holt_22

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Have you waited too long in your area ?

No I drained the block already, pulled all of the blue tabbed plugs and dumped plenty of water out. Just wondering about this engine if there's anything else I should be concerned about or if dumping the water is all I should do.
 

Scott Danforth

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No I drained the block already, pulled all of the blue tabbed plugs and dumped plenty of water out. Just wondering about this engine if there's anything else I should be concerned about or if dumping the water is all I should do.
fluid/filter change and water drained = winterized on the motor
alignment inspection, u-joint inspection, bellows inspection, and gear oil inspection/service = winterized on the drive
 

Holt_22

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fluid/filter change and water drained = winterized on the motor
alignment inspection, u-joint inspection, bellows inspection, and gear oil inspection/service = winterized on the drive

Yes, I got all that. I was more interested in the Cooling System Flush Port on this specific engine, if anyone has experience with it? The quick disconnect looks like you could just use that to inject antifreeze instead of putting the muffs on and sucking it up through the intake on the outdrive.

Thanks for the replies, you've got a ton of info on this forum that is very helpful.
 

Scott Danforth

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Flush ports are for flushing
Draining is for winterizing
Adding antifreeze is for corrosion reasons on extremely long layups
 

Holt_22

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Flush ports are for flushing
Draining is for winterizing
Adding antifreeze is for corrosion reasons on extremely long layups

Ah, well here in Texas they aren't laid up for too long but I see your point, the antifreeze will cause rust more than water?
 

cyclops222

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Relying on Texas electrical system ????? Marinas world wide and boat owners ALL simply follow the manufacturer directions. On how to drain their motors safely. Every year. Really works. Do not modify their procedure. 60 years of draining only. No damage to any motors
 
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