Running antifreeze through outboard

Father's Day

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Ok everyone I'm getting mixed reviews at the dock. I called my mechanic to schedule winterizing of my boat which is coming out of the water Dec.3 we are in NJ and the weather is changing fast, but it's Stripper season and the fishing is excellent. He said he will get to me but he backed up right now, I asked about the motor freezing, he said as long as it down all the water drains out. So if that's the case then why are we running antifreeze through it . Any thoughts
Thanks
Be safe and enjoy the day
 
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Byram

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Interesting. On my outboards here in Ct, my winter ritual has always been to run the engine on the muffs with salt away for awhile, rinse, and fog. Pull each spark plug and a quick shot of fogging oil in each (redundant ). drain and change lower unit oil . I do keep the motor in the down position. fuel stabilizer has already been added.
No antifreeze
 

DennisG01

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Ok everyone I'm getting mixed reviews at the dock. I called my mechanic to schedule winterizing of my boat which is coming out of the water Dec.3 we are in NJ and the weather is changing fast, but it's Stripper season and the fishing is excellent. He said he will get to me but he backed up right now, I asked about the motor freezing, he said as long as it down all the water drains out. So if that's the case then why are we running antifreeze through it . Any thoughts
Thanks
Be safe and enjoy the day
Maybe it would be helpful to tell us what kind of engine you have? Some OB's, it's a good idea to do this... most it's not... with sterndrives and inboards it's absolutely necessary.
 

Father's Day

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Maybe it would be helpful to tell us what kind of engine you have? Some OB's, it's a good idea to do this... most it's not... with sterndrives and inboards it's absolutely necessary Merc 150 EFI outboard
 

Father's Day

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I have a Merc 150 EFI outboard
 

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outboards don't need antifreeze.

The temperature in NJ has just in the last 2 nights gone barely below freezing.
If you are in the water trying to stretch out the striper season then leave your motors down in the water when you tie up. The water is 56 degrees.

On trailer or blocks, after your winter maintainance, leave them down to let them drain. Done. If it gets brutally cold when you pull it and you feel it necessary then remove the T-stat, pour some RV antifreeze to run down through and be done.

your fresh water system and head should be flushed with RV antifreeze.
 
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Mustang65fbk

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but it's Stripper season and the fishing is excellent.
Stripper season eh? Aren't you afraid they might get a bit cold in December? Sorry, I couldn't resist. I've personally owned 3 boats over the years, all of which had year 2000 and newer 4 stroke outboard motors on them and have never used, nor ever even heard of anyone running antifreeze through their motors. My parents owned a late 80's Arima with a 90 hp Yamaha 2 stroke and we never used antifreeze on her either. In the past I've always added a fuel stabilizer into the gas tank before winterizing, then run the motor for 5-10 minutes with salt away connected to the ear muffs like Byram mentioned. I'll generally check the plugs, the oil and so forth as well after I pull the boat back out for the start of the spring/summer as it doesn't make much sense to me to do those things before letting the boat sit for 5+ months. If the motor is running like a dog turd and obviously needs something fixed or changed out like the plugs or oil then I'll do it as needed. But I don't see the need to put brand new oil and spark plugs in the motor and then have it sit. Just my opinion of course. I always leave the outboard as far down as possible so as to help get as much water out of the lower unit as I can. On my parent's old boat we came back after one winter and had a cracked lower unit, I'm assuming from water getting/staying in over the wintertime and then freezing. Won't do that again.
 

Father's Day

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Stripper season eh? Aren't you afraid they might get a bit cold in December? Sorry, I couldn't resist. I've personally owned 3 boats over the years, all of which had year 2000 and newer 4 stroke outboard motors on them and have never used, nor ever even heard of anyone running antifreeze through their motors. My parents owned a late 80's Arima with a 90 hp Yamaha 2 stroke and we never used antifreeze on her either. In the past I've always added a fuel stabilizer into the gas tank before winterizing, then run the motor for 5-10 minutes with salt away connected to the ear muffs like Byram mentioned. I'll generally check the plugs, the oil and so forth as well after I pull the boat back out for the start of the spring/summer as it doesn't make much sense to me to do those things before letting the boat sit for 5+ months. If the motor is running like a dog turd and obviously needs something fixed or changed out like the plugs or oil then I'll do it as needed. But I don't see the need to put brand new oil and spark plugs in the motor and then have it sit. Just my opinion of course. I always leave the outboard as far down as possible so as to help get as much water out of the lower unit as I can. On my parent's old boat we came back after one winter and had a cracked lower unit, I'm assuming from water getting/staying in over the wintertime and then freezing. Won't do that agai
 

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Thanks for the input i'm in the water till the 3rd ill leave the motor down for now on
 

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Urban legend is that the Yamaha's have a few pockets that may trap water even when trimmed down. I always run a gallon of pink antifreeze thru when done for the year and sometimes when coming back from FL in March. $10 of antifreeze is cheap insurance.
 

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I have neve used anti freeze on the outboards. It get vey cold in New England and have never had an issue. As someone stated use pink in the fresh water system
 

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Urban legend is that the Yamaha's have a few pockets that may trap water even when trimmed down. I always run a gallon of pink antifreeze thru when done for the year and sometimes when coming back from FL in March. $10 of antifreeze is cheap insurance.
Early model f350s are known to have pockets of water that may not drain out.
 

seasick

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I am not sure but the pockets were up in the heads so it was important to get the antifreeze circulation up there.In addition, I am not aware of any similar issues on Mercs and I would think we would hear if there were. I would not bother trying to 'winterize' the cooling system on that motor.
 

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I pull my boat, flush Yamaha F250s and leave down. If boat is in the water, my understanding is you leave them down when in freezing temps. I guess if you don’t, you should probably run antifreeze thru the block????
 

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Pump antifreeze thru the flush hose. You want to get it up in the head.
 

seasick

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Pump antifreeze thru the flush hose. You want to get it up in the head.
I don't know if that method works. The Merc cooling flow with respect to the flush ports is different than the Yami design. I don't know how the antifreeze would be pumped into the flush port nor how if would get through the heads.
The question would probably be better handled on one of the Mercury boards. I also suspect that the owners manual for the motor would address winterizing
 

DennisG01

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As noted, it was/is the V8 Yamaha's (and maybe some others, but those for sure) that should have AF pumped through them.

You do not need to worry about AF.
 

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Pump antifreeze thru the flush hose. You want to get it up in the head.

I pull my boat, flush Yamaha F250s and leave down. If boat is in the water, my understanding is you leave them down when in freezing temps. I guess if you don’t, you should probably run antifreeze thru the block????
i put the motor down last night thanks
 
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I wonder if you could rig to push compressed air through? That might push the last bit of water through.