Winterizing a Horizon (fresh water cooled) engine..

J3ff

I've had mostly smaller simpler boats. I'd usually just hook the boat up on muffs, let it heat up and then run 5or so gallons of rv antifreeze through it, to the point where the pink stuff was coming out of the exhaust for a minute or so and then after it all cooled off I'd pull the drainplugs for the risers and that would be that.

Now I've got a 383 FWC full closed loop system. I'm assuming it's the same process-right? Should be even easier as there's less regular water in the engine to get rid of..and with a FWC don't have to worry about heating it up enough to get the thermostat to open - right?

So as far as the water goes, it sound be just a simple flush with fresh water from the hose to get rid of the salt and then run 5 or so gallons of antifreeze through it and done? yes? 

I've googled it, but can't find anyone talking specifically about a mercruiser FWC engine, and def no 383 posts. 

(I'm aware of the other needs, fogging, stabil, etc..) this post is just concerned with getting the regular water out of the heat exchanger/rest of the plumbing..  

diggin2day1

That’s the method that the previous owner of my FWC horizon has been using since 2002... and me too.  No need to warm to open up the thermostat as there is already antifreeze throughout the closed system. 

Liberty44140

Same here - I have 2006 FWC 350 Horizon's. I have the single point drain with the hand pump so I do that first to use the pressure to get the water out. Then I still pull all of the blue plugs to make sure to get any residual water out and I give the starters a quick bump to get water out of the impellers while the plugs are out. I have 4 plugs but you may have more if it is not a single point drain system. After draining the water in to the bilge I replace the blue plugs, hook up the muffs to a 5 gal bucket that has a spigot on it and I run 4 gallons of antifreeze through each engine. I've read that 2 gallons is fine but I like the piece of mind of seeing full pink coming out. Thats it, I leave the blue plugs in for the winter although I know many do not. I dont fog or "cocktail", many here have said its not necessary and I tried it last year and it was really a pain. I do not run it to open the tstat, we dont need to as our t stats are in the internal coolant side, not the raw water side. So the engine really only runs while flushing the 4 gal of antifreeze through. Good luck! 

J3ff

So is pumping with the air pump really needed? I'd rather not move anything that doesn't need to be moved

Liberty44140

Do you have the air actuated system? If so I thought that you had to pump in order for it to drain but I could be wrong.

reneechris14

I pull the blue plug on the port side (this gets the water out of everything but the pump (stays primed). So when the pink comes in it doesn't get deluted. 4 gallons is good with a bucket and muffs. Have a helper give you a holler when they see the pink. Make sure the o-ring stays on as you see a had to buy a new one. Just my way 

reneechris14

It says don't fog an mpi. Just what I've read.

zaverin1

You don’t need to fog carbs or fi engines.
if storage will be for longer then let’s say a year I would spray some fog oil into cylinders instead of the intake anyway.
If you have closed cooling all you have to do is drain your exhaust, coolers, raw pump and cats if you have them.
no need to drain the block since you have freeze in it

Liberty44140

reneechris14 said:

It says don't fog an mpi. Just what I've read.

Right - Book how says that you mix a "cocktail" of gas, oil & stabilizer in a separate fuel tank and run that through for a couple of minutes and you do not fog. I mixed this up last fall and attached it to my cool fuel module. It was really tough to get the fuel flowing and literally nothing ran through. I've read that for 6 months layup this really isn't needed, similar comments on this site, so I didnt do it this year. 

diggin2day1

I put some 2-stroke oil in the fuel/water separator and run the engine while 5 gallons of pink antifreeze flows through the block... shut her down and she’s good for her winter nap. Again, the previous owner of my FV270 has been doing this since 2002 and I’m just following suit. 

jmichels

J3ff you got it right. 350 mag mpi horizon and 383 mag mpi horizon have exact same system .  You don't need to warm them up but I do as well just to get everything moving through. Shut it down, pull the 3 blue plugs or in your case just pump the air pump until the little blue nipples pop up ( haha) and the water will come right out at the bottom. This just lets the antifreeze get in quicker and waste less. Hook up muffs with 5 gallon of antifreeze start em up , let it flow till it comes out exhaust pink and you can shut it down. I personally take 4 ounces of marvel mystery oil and pour it into the throtttle body slowly until I start seeing smoke out the exhaust so I know its in there and shut it down. This coats the top of the valves and components and keeps from rusting over the winter. Many have different views on this fogging process but I have done if that way for years and my motors run like brand new and start up every season no issue. Matter of fact just got my oil tested from Black Stone and they were amazed with the results based on my run time . So it works.

jmichels

Also very important!

If you have sea water pickups that go through the hull make sure you close those off BEFORE you fire up engines when running on the hose. Otherwise it will just run out there and can starve the water pump and burn it out. 

J3ff

cool - I've got one of these, https://www.amazon.com/Camco-65501-Yourself-Boat-Winterizer/dp/B0000AXQU2/ref=sr_1_1?ie=UTF8&qid=1510921285&sr=8-1&keywords=winterizing+boat so the plan is going to be to get the water going to flush, turn off the water, turn on the pink stuff, then go hop up on the boat, wait for the pink stuff to come out of the exhaust, hopefully it'll only be a gallon or two, will let the remaining gallons run through and that will be that.. 

It's 1.88 at walmart for this stuff.. wasting a few gallons isn't a big deal. 

Liberty44140

Jeff, The pink stuff at our Walmart is for water system only, not for engines as it has no anti corrosives, I think it says not for engines on the label. I usually use the $5 per gallon pink stuff from West Marine as it says on the label that it’s for water systems and engines. I’ve seen guys at our marina using the water system only antifreeze from Walmart to do their engines but it wasn’t worth the risk to me. Your call.

J3ff

Ah boy, okay. Will be sure to not make that mistake

J3ff

Thank you