Winterizing a non-running I/O

I recently acquired a boat with a fresh-water cooled Pleasurecraft 350 coupled to a SEI106 (Merc knock-off). I bought the boat as a non-runner, last-minute-before-winter fire sale purchase. Since winters is here, I just need to ensure the engine is winterized, and wrap the boat up. Although the boat did not go in the water this year and it had allegedly been properly winterized the winter prior, the owner talked about trying to get it running in his driveway and I have to assume he had water attached to the out drive.

My question is, how can I properly winterize the motor? The block has ample anti-freeze/coolant but I need to winterize the raw water system - manifolds, risers, heat exchanger, outdrive, etc. I can turn the motor over but I don't have the time to sort things out and get it running at this point.

I was thinking I could put a sump pump in a bucket of RV antifreeze and connect it to a hose going into the RW system someplace. Would this be sufficient, or could I just pull drain plugs from the heat exchanger and manifolds?

or could I just pull drain plugs from the heat exchanger and manifolds?

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Ayuh,..... Air don't freeze, so drained dry is how I winterize,.....

'n don't forget the P/S cooler if so equipped,.....

Just drain the raw water side of the closed cooling system. If this is a half system this will include the exhaust manifolds. For the p/s cooler you can see if it has a drain plug on it if you have access or disconnect one of the hoses. If no access what I’ve done with success is put the drive down, disconnect the raw water intake hose and point it down to drain; then hold it up and fill with -100 marine AF till it runs out the outdrive water intakes. Never had a freeze up doing it this way at temps down to zero.
Also you might want to drain the outdrive oil just in case there is water in the oil to avoid a cracked gear case. If you find water remove the drive & get it pressure tested & resealed over the winter.

Alpha or Bravo drive??? If Bravo, need to drain water out of the (engine mounted) raw water pump... disconnect the hoses and crank the engine for a few seconds.

sandkicker said:

Alpha or Bravo drive??? If Bravo, need to drain water out of the (engine mounted) raw water pump... disconnect the hoses and crank the engine for a few seconds.

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It's a Sterndrive Engineering I believe the 106 is a copy of a Merc Alpha One Gen 1.

swampyankee said:

It's a Sterndrive Engineering I believe the 106 is a copy of a Merc Alpha One Gen 1.

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unless someone has added a belt driven sea water pump your water pump is in the drive and self draining. I would verify this as I thought I recall seeing that with an alfa for closed cooling you need a bigger belt driven raw water pump, it would be feeding water to the heat exchanger.

Would also be worth verifying the antifreeze is correct strength in the block /closed side of cooling system with cheap auto parts store tester

As an update, I was able to drain the heat exchanger and incoming raw water line, and found and cleared the power steering cooler. Upon closer inspection, I was pleasantly surprised to find the manifolds are fresh-water cooled so I just drained the risers.

One item to remember if using RV anti-freeze.
there are TWO different types of RV fluid. One is for plastic lines/pumps etc, & contains no anti corrosion. Usually, in smaller print they sate not to use in metal applications.
The second type can be used in both, & is formulated with anti corrosion additives.
I had a boat with such a system, while based in Yellowknife, North West Territory, Canada. Our boats were stored in -40C during the depth of winter.
I stored as Louc above mentioned. Pull the drain plugs on the heat exchanger, & whatever other plugs the manual says to remove. My manual stated to have the front of the engine higher.
Pull a hose off the bottom of the water pump, & one higher up. After it drains, re-attach the lower hose, then pour some corrosion RV anti-freeze into the upper hose. This will flush any residual water out of the pump, & keep it lubricated.

I used to use the West Marine -100 as it is intended for engine systems and will stay liquid way down to -55*F. But its expensive, so I started to use Sierra Propylene Glycol antifreeze mixed 50/50 with water, I use a refractometer to get the mix right. 50/50 gives freeze protection down about -30*F but you can go higher on the AF %age if need be. So using the West Marine stuff it was 16 bucks a gallon, this works out to a littl more than half, it takes 2 undiluted gallons to make up my yearly storage mix. So to use the best, is costing about 8 bucks a gallon, vs the cheaper -50 and -60 stuff. The -50 and -60 stuff, isn't for places that get down to zero in winter, I don't think it belongs in a cast iron engine in any case. They get hard at about 10* above zero and if there is water left it might not be a good outcome. The higher freeze protection of what I'm using is a good safety cushion. I can tell you I've avoided rust through on this old engine used 20+ years in salt water raw water cooled.

As alluded in Louc’s first sentence, the rating on the bottle is NOT the temperature at which it “freezes”.
West marine -50 “freezes” at +12F- +16F. The -50 rating is the “burst” rating, at which temperature a sealed copper pipe filled with the undiluted mixture will burst. These ratings are from the plumbing industry, & are nearly 100 years old.
It is not detrimental to have PG turn slushy, or even solid in an engine. Turning solid is not what breaks things, it’s the expansion that occurs that does the damage, & even then, only if the fluid is constrained & has nowhere to expand. Some residual water sitting in the bottom of a U shaped rubber hose can safely freeze.
IIRC, from physics decades ago, the force is in the thousands of PSI.
PG products solidify, but don’t expand until we’ll below their freeze point.
Our engines in the Arctic sat in -40C, (which is the same as -40F), & sometimes to low as -45C. I had a closed cooling system, using regular ethylene glycol, mixed to give -50 protection.
We used to suck a bit out & leave it in a bottle in the boat. One winter, even that was slushy.
For others, & the raw water portion of my boat, air is your friend. Air doesn’t freeze. Drain the water, treat the pump as above & you’re fine no matter how cold it gets.
It’s not required to get every drop of water out, water sitting in a low spot can freeze, without damage, as long as the cavity is not full, & sealed. This does require an operator to know his system, & the routing of hoses.
In the 10 years I operated in the Arctic, I never lost an engine by simply draining.
undoing a few clamps & draining is a heck of a lot easier than mixing, pumping, draining.

Been using the what is now $7+ a gal -50 West marine stuff here on the Jersey Shore for years without issue in my Full FWC system. It has gotten below zero (F) briefly a couple of times over the years. Would think the now $9+ a gal -60F stuff more than OK for all but boats in states bordering Canada. Big fan of full drain of non FWC engines.