Winterizing a 1985 Mercruiser 470 - Some basics for a newbie

[kevinstan]

I know this has ben asked and answered a thousand times over - but I still am a bit confused. I am hoping someone can clarify some things for me.... I am just looking for some very basics to make sure I properly winterize my newly obtained Mercruiser 470 I/O motor. I read so much that it has all ran together and I notice so many people doing so much and going wayyyy overboard with it - pumping antifreeze in the block and so on.. I just want to do it the basic and proper way without the risk of any damage to my boat come freezing temperatures that will be coming around my way soon. I hope someone can shed some light on this for me. I have read everything from just unscrewing a screw to filling the fuel tank and adding new antifreeze and so on. I just want a simple basic checklist to properly winterize. Can anyone help me out ?

 

[Bt Doctur]

You have a motor that already runs on a 50/50 mix of regular A/F or atleast it should.Get yourself a AF tester and check .
All that's needed is to drain the raw water side of the heat exchanger by removing the rearmost plug on the bottom rear of the HE.

 

[wrestling coach]

The 470 block is just like your car. It is protected with automotive antifreeze. You should test it with an antifreeze tester just as you would your car. Your protection should be adequate for where you live. As with automobiles a 50/50 mix should be adequate. Take the test by removing your pressure cap and remove antifreeze from the reservoir or if it would be easier test your antifreeze from your overflow bottle. That takes care of your BLOCK. Done. Now you have fresh water in your HEAT EXCHANGER. It is low on your motor near your starter. Large cylinder just about the same length of your block. Think of this as your cars radiator. Inside the cylinder are a series of tubes. Your ANTIFREEZE from your block circulates through those tubes and back to your block AFTER being cooled with fresh water drawn from the lake through your lower unit and then out the exhaust. The water that remains in your heat exchanger WILL FREEZE and must be drained. On the bottom rear of your heat exchanger you will find two drain plugs. The plug farthest aft (rear) drains that water. Pull that plug and let the fresh water drain to your bilge. Take a paper clip and poke around the drain to be sure it is clear and free of sand etc. Let it all drain out. Leave the plug out if you want just remember it in the spring. If you take out the other plug in front of that one you will get ANTIFREEZE......wrong plug.....put it back. That's it. You are done!!!

You have two things to do.
1. Check your level of protection of your ANTIFREEZE.
2. Drain the fresh water out of your heat exchanger.

Dennis

 

[stonyloam]

The coach has it. I drain mine right on the ramp when I pull the boat for the winter. Pull the aft exchanger plug and the boat plug and let it drain. If you have a power steering cooler it will be on the vertical hose going from the aft of the exhanger to the exhaust elbow. It will drain when the exchanger drains. I do not fog mine, but that is up to you. a battery maintainer is a good idea. as for the gas tank, if you use 10% methanol fuel, a can of stabilizer can't hurt, full or empty should not make any difference.

 

[Watermann]

Lots of good tips in this link from Don on winterizing. http://forums.iboats.com/forum/engi...w-to-winterize-your-engine-and-drive?t=178695

 

[Oshawapilot]

Just bumping this thread instead of starting a new one, these are the exact simple straightforward winterizing details I was looking for

Long story short we just found out that the boat mechanic my sister contracted to winterize the twin 470's in her boat (as well as the plumbing) never showed up and actually did the work. It's been an exceptionally good stroke of luck that the weather has been abnormally warm and I don't really have much concern that anything will have been damaged so far, and given as how they can't find any mechanics willing to come to the boat this time of year it looks like I'm going to do it for them this coming weekend.

The engines themselves seem extremely straightforward, I'm not really concerned about that whatsoever, however is there anything necessary on the outdrives? It has twin Alpha 1 sterndrives.

There is no power where the boat is stored. I can use the onboard inverter which will give us 1200watts (enough for some spot lights and such to work on things) but not enough to run tools for the most part.

Guidance appreciated.

 

[wrestling coach]

You should change the oil in the lower units to be safe. If you got water in the lower unit in enough volume it could freeze and crack the lower. How does water get in there? Gaskets and seals can leak. When you drain the lower unit oil notice the color. If it is milky colored there is water in there and you wouldn't know it unless you changed it. I also lower my outdrive to a more neutral position so the bellows is in a more relaxed position for the winter.

 

[Oshawapilot]

You should change the oil in the lower units to be safe. If you got water in the lower unit in enough volume it could freeze and crack the lower. How does water get in there? Gaskets and seals can leak. When you drain the lower unit oil notice the color. If it is milky colored there is water in there and you wouldn't know it unless you changed it. I also lower my outdrive to a more neutral position so the bellows is in a more relaxed position for the winter.

Sounds good..just draining them and leaving them empty for the winter doesn't present any issues, does it? I'd like to keep the job as short and sweet as possible, worry about oil changes on the engines and refilling the drives in the spring.

As for water in the drives, the water pumps, etc ...is everything self draining? I don't have muffs to put antifreeze through, but as I understand it with the intercooled 470's once the heat exchanger is empty everything else should gravity drain?

And yes, the boat is up on big enough blocks that the drives are lowered and sitting in cruising position.

 

[stonyloam]

When you drain the out drives, the water will come out first. You do not have to refill them, but you should put the plugs back in, just remember to refill in the spring. Everything else is self draining. You should check the antifreeze in the engines with a antifreeze tester to make sure it is about 50/50. Do that before draining the exchanger and outdrive so that you can run the engine on muffs should you need to add antifreeze, you need to make sure it circulates through the engine and mixes properly.

 

[Oshawapilot]

When you drain the out drives, the water will come out first. You do not have to refill them, but you should put the plugs back in, just remember to refill in the spring. Everything else is self draining. You should check the antifreeze in the engines with a antifreeze tester to make sure it is about 50/50. Do that before draining the exchanger and outdrive so that you can run the engine on muffs should you need to add antifreeze, you need to make sure it circulates through the engine and mixes properly.

Thanks, sounds good.

I will test the antifreeze although I'm pretty certain they will be correct 50/50 - I know they top up with nothing but store-bought premix so no water has ever been added, but I'll check nonetheless.

Really hoping we don't need to run the engines as, like I mentioned, there is no hydro nor water available where the boat is parked - hydro is about 300 feet away at closest, and water probably another 100 past that....so muffs to start things are not an option unless there's some absolutely critical "no other choice" problem that would require it, and we'd have to go and buy hundreds of feet of garden hose to make that work.

Perfect world I'd like to fog the engines and run the carbs dry, but again, not likely gonna happen. At this point I just want to make them winter safe (and the plumbing needs to be done as well) in as short a time as possible and then be done with things until spring.

 

[stonyloam]

I have had my 470 since "91" and have never fogged it, or ran the carbs dry. No problems ever. Sounds like your antifreeze should be OK. You might want to pull the batteries out and take them home and charge them up, and keep them charged over the winter.

 

[stonyloam]

Yeah, drain the seawater out of the exchangers, and make sure there is no water in the out drives, and make sure the hull drain is open and clear (in case the cover fails, you will not accumulate water in the hull) and you are "winter safe".

 

[Mercruiser420]

Fuel stabilizer

 

[Oshawapilot]

They found another marina that was able to do the winterization for them today. They wanted to run the engines (presumably to do a full fog and such) but I suggested that they just go with the quick and dirty approach instead given the situation.

It's done. Thanks the for the advice everyone.