1996 Four Winns Sundowner with 5.0 Cobra engine and drive

Lou C said:

Look at one for an Etec

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Perfect! Thank you!

The boat is the one in my profile and the subject of this thread.

Until now I've been hoping to get one more outing on the boat before winterising it, we had some decent weather with sunshine a few weeks ago. But now it's getting colder and it's forecast to be freezing in a couple of days, so now it's time to winterise it.

Today I removed the thermostat housing and disconnected hoses from it, opened the drain plugs on both sides of the engine block and drained all the water from the engine, retightened the engine block drains and filled the engine with antifreeze solution. I then checked antifreeze had at least reached the drain plugs by slackening to check the colour, it seems as green as the stuff I put in so it seems the engine is protected? Disconnected the input pipe from the inboard raw water pump, poured antifreze into the raw water pump output pipe (which slowly drained out through the raw water pump input since the raw water input hose was already disconnected) so I think the raw water pump is protected? Poured antifreeze solution into each exhaust water inlet through the hose until it poured out of the exhaust outside the boat, so I think all parts of the exhaust are protected?

Will this be enough or have I missed something?

I am a bit concerned about whether the PAS cooler will be fully drained of river water... Last year I disconnected the input hose from the PAS cooler and filled it with antifreeze but this year I haven't removed the folded canopy from the boat yet and with it still fitted access to the pas cooler is restricted. I haven't been able to put antifreeze in the pas cooler yet, will the PAS cooler fully drain with the raw water hose that feeds the raw water pump disconnected or should I make sure to put some antifreeze in it?

The drive is still fitted. Last year I didn't remove the drive for winter but I did pour antifreeze into the raw water input hose that connects to the PAS cooler, so back flushed the drive input water passageway with antifreeze. This year so far I have lowered the leg so the skeg is close to the ground, not quite the fully down position because it won't go fully down before it hits the ground but seems vertical enough. Will any water (that could freeze) remain in the drive?

If you've drained the outlet of the raw water pump, your PAS cooler is drained. Next year, if you're gonna winterize with antifreeze, I would use the non-toxic pink RV antifreeze. I personally don't use antifreeze. I just drain the raw water cooling system (I have a half closed cooling system with a heat exchanger and auto antifreeze in the block). This involves draining both hoses to the raw water pump, blowing in the inlet hose with the drive down, and draining the exhaust manifolds, either by disconnecting the cooling hoses on the front, or opening the drain plugs I put in the backside of the manifolds. Google Volvo Penta exhaust drain plug to see an example.

With an open system like yours I think just draining the block is sufficient without having to open the thermostat. Others may chime in on that.

If your drive is mostly down, it's drained enough for the winter.

Thanks Horigan.

Tomorrow I'll blow through the hose that is usually connected to the raw water pump input.

When I first opened the block drain plugs I still had the thermostat housing fitted, water drained out of the port drain but not the starboard drain, then when I started to remove the thermostat housing water drained from the starboard side drain too. I'm not sure why that happened.

I don't know if it's better just to drain or to use antifreeze... One thought was if I just drain it maybe not all the water will come out, at least if I used antifreeze any water left in the system would likely be mixed with the antifreeze. Another thought was antifreeze(coolant) has anti-corrosion properties, maybe parts are less likey to corrode if left filled with antifreeze than they would be if just drained? Also last year I had a few problems with the engine running too cold due to debris like bits of rust holding the thermostat open, antifreeze has a kind of slippery feel and I hoped leaving it in the block over winter would help dislodge flaky rust in the block.

You know it's the eternal debate, AF vs simply draining. I do the AF because, I'm a salt water boater and we need all the anti-corrosion help we can get. If in freshwater, and your intake doesn't show flaking rust perhaps draining well is good enough. One thing I will say, my old F/W still has the original block and intake manifold, the intake does not have flaking rust in the water passage, despite being in salt water all season. It's been filled with AF every winter, for 23 years.
Tomorrow I'm using my inspection camera to check the elbows/manifolds for internal leaks. Now on season 6, so might have to do them, depending on what I see. Over this past weekend I resealed the water pump shaft on my OMC Cobra outdrive, there was a lot of water in the gear oil this year, so had to do it, used an improved water pump adapter with a double seal.