Winterizing Yanmar

[lr172]

This is the first year that I will be winterizing the 3GM in my H34 and had a question. It is fresh water cooled and seems pretty simple to drain and get some anti-freeze into the heat exchanger. My question is with the muffler. It must be full of water and I'm wondering if there is a way to drain it. I would prefer not to run gallons of antifreeze through the engine if not necessary.

Thanks for your assistance.

Larry

 

[Ed Schenck]

Everyone else does. Only takes a couple of gallons to protect the strainer, the heat exchanger, and the exhaust including the muffler. I fill a pail, add an extension to the hose from the seacock, stick it in the pail and start the engine. Nothing to it.

 

[navigator97]

I agree with Ed. It is really a strait forward process. I just did mine but I also needed to change the engine oil "on the hard" as well. I put a length of hose (5 - 6 Ft.) from the strainer input then into the pail. I filled the pail with fresh water from a "shore water" hose with a shut off valve on the bucket end of it. I started the engine and adjusted the valve so that the water into the pail from the hose matched the rate the engine was sucking water out of the pail. I ran it for 16 to 18 minutes to warm up the engine (for oil change - no need to warm foe winterizing). At that time I shut off the valve and let the engine continue sucking water until the pail was just empty and poured in a gallon of Ban Frost 2000 antifreeze. As that was just about empty again I poured in a gallon of -100F Antifreeze. Just as that was empty I shut off the engine. Engine was now winterized and I started the oil change. No problems - pretty simple.

 

[Dan Johnson]

Larry...

weigh the cost of a couple of gallons of anti-freeze ($3.99 at WallyWorld) against the cost of a replacement Yanmar block.

I have a valve assembly and hose connection between my strainer and raw water pump. Once at the storage marina, I close the thru-hull and run a bucket full of anti-freeze (at least two gallons) through the engine and muffler, watching for the pink stuff to appear out the exhaust. Then the engine is shut down, oil and filter changed, and it's ready for haul-out.

Once on the hard, I reconnect the bucket and let gravity back flow the anti-freeze through the strainer and out the pick-up thru-hull. Takes about a gallon.

Total cost so far for anti-freeze = $12.00 vs. new Yanmar block at probably in excess of $4 or $5 K.

 

[CHARLIE STAGE]

Following the above procedures pretty much, I also hang a 5 gallon bucket from my rail to catch the water and residual antifreeze so it doesn't pollute or entice someones pet to an early death. I do the same before the launch with clear water the end result. Antifreeze listed as environmentally friendly is still a problem.

 

[klemsaba]

I just winterized my YSM8 yesterday. I didn't use even a gallon of antifreeze before it started coming out the exhaust. Any opinions on if I need to run more through?

Thanks.

 

[Scott B]

I just winterized my YSM8 yesterday. I didn't use even a gallon of antifreeze before it started coming out the exhaust. Any opinions on if I need to run more through?

Thanks.

Yes you do, even if it's pink, it still could be mixed with water and reducing the percentage of antifreeze in the engine, and raising the temp that the mix will frezze in the winter = cracked block.
-50C antifreeze is only good to -50C when it is not diluted by water still left in the system.

 

[lr172]

Thanks for the help guys. I'll go that route.

As a point of reference, my H34 Yanmar is fresh water cooled and I am guessing most of the H34's were. The raw water side does not touch the block, so I don't understand all the warnings about cracking my block to save a dollar. The raw water touches only the heat exchanger/manifold which has a simple drain for emptying the raw water. After this, water remains only in the muffler and the RW pump and strainer, if you don't remove the hose to drain them. The only thing that can't be drained in 5 minutes is the muffler.

Larry

 

[rochesterdriver]

Ok, I'm following this thread and need to opine...

I've a 2GMF so am in much the same... well, boat.

In prep for winter I only had to do the drinking water system and the engine exchanger.

I did the drinking water in the normal way, drained everything, then pumped the pink stuff through until it showed at the galley and head sinks.

For the exchanger I opened the sea cock at the inlet, disconnected the hose that runs from the raw water pump to the exchanger. I blew compressed air through in both directions while a helper watched at both 'outlets'.

It appeared that water came out both 'outlets'.

What more would one need to do I wonder?

Thanks folks,

Rich.

 

[lr172]

Rich,

Your method covers everything except the muffler, which is below the water line. The exhaust has a loop between the exit and the muffler, keeping the muffler and some exhaust piping full of water. The hose is fine, but I don't think the fiberglass muffler will handle the expansion.

I cannot come up with an option for draining, so you need to mix in antifreeze. Problem is, you can't just pour it in because the engine's exhaust pressure is used to push the water up over the loop. Learned this the hard way this spring

seems easiest to just run a couple gallons through the system to force it into the muffler. I would install a drain on my muffler if I could get to it easily, but access is poor for my H34.

 

[rochesterdriver]

Larry,

An excellent point on the muffler. I've now run some additional pink stuff into the exhaust system with my hand pump (up stream of the raw water cooling pump).

Seems to me as thought that outta do it.

Many thanks for the heads up and straightening me out.

Rich.

 

[Barnacle Bill]

Come on folks. There is a closed system in the engine and a fresh water (raw water) system too. The heat exchanger is apart of the closed system where you have a reservoir for antifreeze. You don't have to drain this part of the block. Leave the antifreeze in place. The part of the system that takes lake or sea water needs to be drained and that is apart of the aqua lift muffler (exhaust) part. You need to look at your owner's manual and find the plugs where you can drain the water out of the raw water (lake or sea water intake system) system. When you drain those, then you can replug the plugs and then hook up the hose from the seacock to the outside of the hull and feed antifreeze through the engine so you know that you have it covered. Most mufflers have a drain plug that you can unscrew to drain all the water out of it.
Don't use pink RV fresh water antifreeze for engines. Use antifreeze designed for engines. There are non toxic types that won't pollute the water when you start the engine up next spring.

 

[CHARLIE STAGE]

I have yet to find an environmentaly safe antifreeze that did not have a disposal warning. You may choose to dump yours in the water but I will still catch most of mine in a bucket. It works and it is a sure bet it won't pollute the water.