Safest way to add antifreeze to open loop cooling system / exhaust

[Floydy]

Hi Everyone,

I used the air compressor method to remove water after flushing the open loop system. It didn't work as well as I'd hoped and there is still a small amount of water in the system. You can hear it when you apply air at the flush out port. It sounds like when you suck on a straw with nothing left in the glass! Its only a small amount of water but it will start to freeze in the next few weeks and I'd rather be safe than sorry. Is it ok to simply run some antifreeze into the flush out port and let it drain out through the exhaust port and pump? Seems easy enough to do with a short hose and a bottle anti-freeze but is there any hidden risk such as antifreeze entering the engine? Or do you need to run antifreeze through with the engine running?

Thanks in advance.

 

[Luc Lafreniere]

It's very commonly done. I switched to air compressor a year ago since it was simpler. The water leftover is NOT (IMPORTANT TYPO INITIALLY) enough to cause damage. It stays in your waterbox etc. Where there are large cavities and expands a bit into it. No damage. As long as you removed the bulk, you're good.

If you do want to do antifreeze, yes, run the engine. It's exactly the same as flushing with water. Same risks. Many pump it in, others gravity feed it. But make sure the engine is running. A couple of gallons is enough. Some put way less. Use RV antifreeze.... Apparently some marine versions exist because it's friendlier to marine parts.

 

[Floydy]

Thanks Luc, you need to start charging money for your advice!

 

[Luc Lafreniere]

It would be in Canadian dollars and considering how many Americans are here and the exchange rate, I'd make pennies! Lol

 

[Floydy]

See, what you do is require payment in USD. You'll make a fortune!

 

[Julian]

Hi Everyone,

I used the air compressor method to remove water after flushing the open loop system. It didn't work as well as I'd hoped and there is still a small amount of water in the system. You can hear it when you apply air at the flush out port. It sounds like when you suck on a straw with nothing left in the glass! Its only a small amount of water but it will start to freeze in the next few weeks and I'd rather be safe than sorry. Is it ok to simply run some antifreeze into the flush out port and let it drain out through the exhaust port and pump? Seems easy enough to do with a short hose and a bottle anti-freeze but is there any hidden risk such as antifreeze entering the engine? Or do you need to run antifreeze through with the engine running?

Thanks in advance.

What Luc said.....no anti freeze is needed as the water won't do any damage. Yamaha doesn't recommend it. But if it makes you feel better....pour away....its not going to hurt anything but the few dollars it cost.

My boats have lived in an unheated Wisconsin barn through frigid winters and fared just fine.