Winterizing Yanmar 2QM15

[Wm. Gill]

I have a new to me 79' C&C 30 with a Yanmar 2QM15. I am winterizing her for the 1st time, but am used to doing things by myself, so I am relearning, and adapting (a little different than my last boat, a sedan bridge). I have not had the chance to wire in a remote starter box, not to mention that a diesel can't be stopped with a 'run/off' switch. The 360 Chrysler Marines had large (6" diameter) intake strainers providing a nice bowl to pour antifreeze into. They were below deck far from the lower station, thus the need for the remote.

On the C&C the 'strainer' is much smaller. and has no 'bowl' to poor the antifreeze into. The hose from the through hull to the strainer is only 6" or 8" long (and I'm not sure the ID). Years ago on my Catalina 27' I could detach the intake hose and put it in a bucket of antifreeze, and I don't remember having a '2 places at once' problem.

I have a couple things I would like some thoughts on. First, if I make a jig that attaches to the inlet hose (where the through hull normally connects) and run a clear vinyl hose to a bucket in the cockpit where I can see that's happening on the intake side, and from where I can operate the controls and also see the exhaust, will there be enough suction to draw the antifreeze from the bucket? The answer to that may render the second question moot, but here it is anyway: Rather than letting the engine start, and increasing the risk of not being where I can stop it quickly, what if I pin the regulator so no fuel gets to the engine, and pin the decompression valve open so the starter motor can turn the engine freely?

Guess while I'm at it I should find the impeller and replace it.

 

[dlochner]

Remove the sea water intake hose at either the sea cock or strainer which ever is easier. Removing from the seacock is easier on my boat. Get a length of appropriately sized vinyl hose, reinforced is better, a couple of cheap clamps and a male to male connector. Connect the vinyl hose to the seawater intake hose. Stick the vinyl hose in a bucket with AF. Start the motor and suck all the AF out. When it stops coming out of the exhaust, shut the engine down. In the few seconds it is running without any coolant in the heat exchanger, no damage will be done because the motor will not have gotten hot enough.

Service the impeller after winterizing.

 

[BarryL]

Hello,

As mentioned, I find it easiest to remove the raw water pump INTAKE hose. I take another hose (About 4' long) to the water pump and I put the other end in a bucket. I pour 2 gallons of antifreeze into the bucket. I start the engine and let it idle. It should easily suck the antifreeze from the the bucket. I stand in the cockpit and water the water being expelled. When I see antifreeze being expelled I stop the engine.

I do the engine first and then I pour any left over antifreeze into the the head and then I finish the head, domestic water system, etc.

Barry

 

[PaulK]

We run the engine for a while with water in the bucket to get the oil warmed up so it's easier to change the oil. Once it's warmed up a touch, THEN we put the anti-freeze in the bucket, and continue running the engine until the anti-freeze starts coming out the exhaust. Then we shut it down, leaving the anti-freeze in the system. We then change the oil (and the filter) because we don't want whatever crud and precipitates that might be in the used oil coating, settling, or pitting things inside of the engine over the winter. Running the engine also helps to warm up the cabin a bit, making winterizing the water systems a touch more pleasant. Don't forget to change any zincs inside the engine too. Spring IS coming. Be patient.

 

[Wm. Gill]

Remove the sea water intake hose at either the sea cock or strainer which ever is easier. Removing from the seacock is easier on my boat. Get a length of appropriately sized vinyl hose, reinforced is better, a couple of cheap clamps and a male to male connector. Connect the vinyl hose to the seawater intake hose. Stick the vinyl hose in a bucket with AF. Start the motor and suck all the AF out. When it stops coming out of the exhaust, shut the engine down. In the few seconds it is running without any coolant in the heat exchanger, no damage will be done because the motor will not have gotten hot enough.

Service the impeller after winterizing.

What you describe is what I had in mind, but not much room for a bucket below, so I was going to bring the new hose straight up and into the cockpit. That's about a 4' rise from the strainer. Actually about a 2' rise from the bucket, and a 4' drop to the strainer. I also wasn't sure how much AF it would take, but if 2 gal is more than enough I guess I really don't need to see the bucket. I will just have to figure a way to place the bucket. The previous owner used to do it 2 man, 1 hanging upside down with a funnel jammed into the hose,
The oil only has about 8 hours on it so I figured spring, and pre-haul out next season. Actually looks like I can drain it with the drain plug, instead of syphoning it from the dipstick tube.
Didn't think about zincs. Not sure where, they might be. May have to have my $100/hr 'helper' show me how this time.

 

[Claude L.-Auger]

It will work if you put the bucket in the cockpit but be sure to remove the hose immediately from the bucket after shut down. If not, gravity will keep bringing AF down to the engine and since there is no more exhaust gases pushing it towards the exhaust, it will seep into the cylinders through the opened exhaust valves. Don't ask how I know ! Also, just because you see antifreeze coming out of the exhaust it does not mean that the system is winterized properly. There is a lot of water in the system when you get started and quite a bit of it will mix with the AF. To be sure, take a reading of the density of the AF after you've shut down the engine. If it show a value that you're happy with based on coldest possible temp in your area then you're good to go. If not, run more AF through it until satisfied. AF is way cheaper than a cracked block or head. Call it insurance if you want.

 

[dlochner]

It will work if you put the bucket in the cockpit but be sure to remove the hose immediately from the bucket after shut down. If not, gravity will keep bringing AF down to the engine and since there is no more exhaust gases pushing it towards the exhaust, it will seep into the cylinders through the opened exhaust valves. Don't ask how I know ! Also, just because you see antifreeze coming out of the exhaust it does not mean that the system is winterized properly. There is a lot of water in the system when you get started and quite a bit of it will mix with the AF. To be sure, take a reading of the density of the AF after you've shut down the engine. If it show a value that you're happy with based on coldest possible temp in your area then you're good to go. If not, run more AF through it until satisfied. AF is way cheaper than a cracked block or head. Call it insurance if you want.

This is why I use ethylene glycol instead of propylene and let the entire gallon flush out. Any residual water will mix with the EG and not freeze solid. Also don't rely the cheap hydrometer, spring for a good refractometer like this one from Amazon https://amzn.to/3bP93z7.

 

[Tally Ho]

On my O’Day 322, I usually run the engine on haulout day, over to the fuel dock…pump out holding tank…top off fuel if needed…then back to my slip where I change the oil.

Then after I am hauled out, I winterize the engine (Yanmar 2GM20F).

I pull the hose off the water pump…easiest for me to reach, and used a piece of hose to run to a gallon jug of pink AF…
Start the engine, run down below and get ready to move the hose into a 2nd gallon of AF. As it get to the bottom of the 2nd gallon, I use the fuel cut-off on the engine to shut down the engine.

Not sure if your engine has this, but if you have a T handle or something to pull in the cockpit to shut off the engine, follow that cable to figure out where it pulls a fuel cut-off…

After 6 years winterizing Tally Ho, it seems easy peasy And I do it all myself.

Greg

 

[Claude L.-Auger]

This is why I use ethylene glycol instead of propylene and let the entire gallon flush out. Any residual water will mix with the EG and not freeze solid. Also don't rely the cheap hydrometer, spring for a good refractometer like this one from Amazon https://amzn.to/3bP93z7.

Likewise I use Ethylene Glycol ! Not only does the EG mix with residual water, but it also contains some inhibitors that are better for engines than the alcohol based antifreeze. I admit to having used the cheap hydrometer but since I am extra cautious and living in a cold country, I make sure what is collected out of the exhaust (at my club we do not let it fall on the ground but collect it and take it to a safe disposal place) test at -40 or below ! A little more expansive but as I said, EG is cheap compared to a cracked block. As for hands required, every year 2 of my friends and myself do our boats together. So one hold the intake hose in the antifreeze bucket, one starts and stops the engine and the 3rd one holds the collecting bucket under the exhaust. We do all 3 boats one after the other and it doesn't take more than 30 minutes. BTW with the same friends we start our engines in the Spring while boats are still on their cradle. Same procedure except we run clean water in the bucket instead of antifreeze. And we collect the dumped antifreeze for disposal. 2 reasons for doing it while on the ground: 1) We don't dump antifreeze in the lake water and 2) it ensures that the engine starts easily when boat is launched !

 

[Wm. Gill]

...
I pull the hose off the water pump…easiest for me to reach, and used a piece of hose to run to a gallon jug of pink AF…
Start the engine, run down below and get ready to move the hose into a 2nd gallon of AF. As it get to the bottom of the 2nd gallon, I use the fuel cut-off on the engine to shut down the engine.
...

At 71, I'm not as nimble as I once was so "...run down below and get ready..." is why I like having a remote control. On my sedan bridge I used a trailer wiring connector so I could just plug and unplug my remote starter box when working below with the engines. May have to make one for this boat next season.
I am going to look to see if the water pump is more accessible than the strainer. I should be able to look down and watch the bucket from the cockpit. Otherwise a bucket in the cockpit, where I can watch the AF from the engine controls (being careful to insure no syphoning of AF after shutdown) will have to work.

 

[RoyS]

You asked if you should run the engine or just crank it. If you have a water lift muffler you should either drain the muffler or run enough antifreeze through it to displace all of the water. Difficult to blow all of the existing water out of the muffler even with engine at idle. Takes a second of increased throttle to blast it out. As for a remote start button at the engine, purchase a Yanmar start button. Put appropriate insulated quick disconnect stakons on the two short lead wires. Put a corresponding stakon on a new hot wire near your starter motor solenoid. (Short red wire with blue stakon below) Whenever you want to start your motor at the motor, just disconnect the existing wire plugged into the solenoid (black wire with yellow stakon), plug one of the short wires on your new button onto the solenoid. Plug the other button wire into your new hot wire stakon and press to start. You can operate the throttle from there as well. Remove your new start button when finished.

 

[Wm. Gill]

I found a way to run the engine and monitor input and out. problem is I couldn't really tell if exhaust was purple. I ran 2 gallons of antifreeze figuring that was overkill. now I am not sure.
Any Yanmar 2qm15 owners have any ideas?

 

[Boomer2it]

I winterize my engine on the hard, I have a valve installed on engine side of water intake seacock, shut seacock attach hose line to intake valve with 3 gallons antifreeze in a water container put the hose in the tank and start engine once it sucks up and runs antifreeze into engine I shut off from the engine throttle and verify antifreeze puddle on the ground under exhaust.

 

[John T1594]

I had a raw water cooled 2QM15 on my 1980 H30. To winterize the engine I would run two gallons of -100 antifreeze through a HOT engine, using a bucket and hose attached to the raw water pump. I would also remove the thermostat to confirm that the antifreeze had made it through the exhaust manifold. I would replace the thermostat every year anyway as it would easily corrode in salt water.

 

[Wm. Gill]

You asked if you should run the engine or just crank it...

Didn't mean to be curt. You did answer my original question. Running the engine was always my 1st choice, but it didn't look doable. I'm glad I found a way, and glad you pointed out a couple things to make "just spinning the engine" a highly unfavorable alternative.

 

[Dalliance]

John T1594 makes a good point about winterizing when the engine is HOT. The Yanmar 2GM in my ‘82 H30 has a temperature by-pass. If the engine is not up to the correct temperature when you send the antifreeze through, it will by-pass the engine block, go straight to the mixing elbow and out the exhaust. It looks like you winterized your engine, but you didn’t.
Check the cooling system diagram for your 2QM15. If it looks like this one for my 2GM, you must make sure the engine is up to temperature before running the antifreeze through.

 

[Tally Ho]

Good point, but not an issue on a 2GM20F or other freshwater models.

Greg

 

[Dalliance]

Have to love Google. Here is a screenshot of the cooling system diagram for a Yanmar 2qm15. It shows a by-pass pipe. Different configuration than my 2GM, but it appears to be functioning in the same way. Both are raw water cooled.

 

[RoyS]

There are two drain valves on the 2QM15 that you can use if you still have raw water cooling. The one on the port side works well but the one on the starboard side is sticky and fragile. If the starboard side fails to drain after opening push an object up into it to displace debris lodged there. If it will not open then unscrew it from the casting to drain.

 

[Wm. Gill]

There are two drain valves on the 2QM15 that you can use if you still have raw water cooling. The one on the port side works well but the one on the starboard side is sticky and fragile. If the starboard side fails to drain after opening push an object up into it to displace debris lodged there. If it will not open then unscrew it from the casting to drain.

Not seeing the drain valves in the service or parts manual diagrams. Any help locating it would be appreciated.