Do I really need to run AntiFreeze through engine?

T

toofast

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So I have a "new" Merc 496 Mag engine...that is closed cooling. It still has the raw "fresh" water intake of course to run through the heat exchanger to remove the heat from the AntiFreeze that runs through the block.

It has the "pressure" system where you pump air into the system and then all the "valves" release all the water out of the engine.

So basically I am told by local mechanics there is no longer a need to run antifreeze through system. Still have to EFI Fog, etc...but skip the antifreeze part.

Does anyone have any real world input? Could this be true?
 
Are they Horizon's? If so, then yes, all the cooling water is flushed from the engines and no you do not have to run antifreeze through the engines. I have 6.2 Horizon's and evac'd the cooling water from the engines a couple of times last winter. Nice thing about the setup is the engines are ready for use with about a 10 second spring reset button. Go out for a winter cruise and winterize the engines in less than 30 minutes. Depending on where and how you lay up for winter, a couple of heat sticks or an ER heater may do more than anything else.

I believe Ghost has block heaters on his oilpans that keep the ER at close to 70 degrees F.
 
David, I don't think that's me. I do have block heaters, but my single 30 amp shore power at the slip is not enough to run them in the winter, along with the frige and a heater or two. Block heaters and space heaters safely installed are fine, except when the power goes out, which is at its highest risk when you need it most.
 
Well, I think they use the Horizon "name" for inboard's only. I have a BIII setup. One of my good friends has inboards, same exact engine, etc...his are Horizon 8.1, mine are called 496 Mag's.

The setup for the flushing system is the same...
 
I've been winterizing my 2001 8.1 Merc Mag since I bought it new. Running anti-freeze through the engine is the way to go, IMHO. Storing it "dry" and drained leads to internal rust build-up. The anti-freeze should have rust inhibitors in it.

Shut the treated engine down after you see the anti-freeze exiting the exhaust. See other posts in this forum to see what "formula" of fuel treatment to use during the shut down process. I use 2-stroke oil and Sta-Bil in my mixture.

Peter
 
Cobalt - ok that is sort of what I assumed.

But to verify...you do not "purge" the system when complete...meaning you leave antifreeze in the sytem.
 
That is correct- do not purge. The mixture left in the engine protects it from freezing and (hopefully) eliminates the chance of rust.

I have been using George's Boat Fix mixture (35% 2-stroke oil) for years and it has worked well.

Peter
 
Check with Merc. Some have coated insides to preclude rust and corrosion.
 
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