Yamaha Outboard Unique Winterization

[Eager]

We purchased a 2017 C-24 C in September. We are keeping it in a boathouse in the South Puget Sound area that rarely gets a hard freeze, and we use it in the winter months once every 2-3 weeks at a minimum. Other threads here have gone over winterization very clearly, but our situation is fairly unique. At our marina the boats rest on very soft mud at the lowest tides. (There are much more expensive inboard boats than mine that have been moored at this marina for years so that part I’m not worried about.)

I have read where others recommend putting the outboard in the water for the coldest nights (which generally pass after a few days in this part of the country.) But this would not be a good idea for a boat resting on the ground, obviously.

We have several nights ahead of weather forecast to be a bit below 24 degrees in the evenings. Even if it’s warmer, the possibility exists at some point that we could get a few nights around 10 degrees during our winters every few years. What steps can I take to make sure my motor remains in good working order?

 

[Bruce Moore]

Bumping post delayed in moderation queue.

 

[TBates]

Hi Eager, one thought would be to pump pink RV antifreeze through the engine using the flush port on the side of the engine. If possible, I would first run the engine up to temperature to be sure that the thermostat is open, then submerge a pump in a bucket of antifreeze, then connect your hose right to the side of the engine and turn on the pump. It shouldn't take much, but I would continue running the antifreeze through until you see it start to exhaust out of the prop.

Feel free to shoot us a call with any questions at all.

Thank you,

-Tim

 

[Jimjudynick]

Tim, I have also seen the question of whether it makes sense to leave the outboard down in the water vs the standard up position during cold nights like we are going to be seeing over the next few days. We are not prepared to go the rv fluid route but want to make sure we do all we can. What are your thoughts on the “up or down” question?

 

[IFLY2]

We have a 2019 R27OB (on the water in Gig Harbor) and when it drops down below freezing we lower the outboard down into the water. I've spoken with the RT guys and Yamaha and all agree for boats on the salt this will protect the motor. I've owned outboard for 50 years in very cold climates and never had a problem with storing them this way. Tim's suggestion works well also. Merry Christmas!

 

[BB marine]

I'm not sure what running the engine with anti-freeze is going to do. The outboards are self draining blocks. When the water pump quits pumping ( this is when the engine is turned off) the water starts to drain. The water pressure from the pump is what maintains the water in the blocks cooling passages. Once the block is full of water the water discharges out the exhaust via the midsection housing. When the engine is shut down the water pressure from the pump goes to 0 psi and the water drains down. It is always a good idea to to let the engine stay in the running position (vertical ) for a few minutes after shut down to get a better, quicker drain. It is also recommended to flush the engine with fresh water after running it in salt water. When using the Yamaha flushing devise this will take the place of the engines water pump filling the block and discharging the water out the exhaust cavity and draining down the midsection.

Leaving the motor in the raised position should not effect the engine block during cold fronts causing freeze damage. The reason for leaving the engine in the down position is to confirm that the lower unit exhaust hub is not full of water and exposed to freezing tempertures. If it is full of water and freezing temperatures are experienced the water sitting in the cavity can freeze -expand- and crack the housing. I' have replaced many gear cases because of this. Many people winterize their outboards (flush, fuel treatment,replace gear oil, fog and store with the engine raised up in the tilt position on a trailer. Rain water starts to fill the exhaust hub via the thru hub exhaust prop and the housing gets full of water. The water freezes and cracks the housing. The fix for this is leave the engine in the full down position when in storage so water can not fill the cavity. When leaving the boat in the water it is best to keep the engine in the down position during freezing temperatures. Normally the surface water may skin over with ice but that is it. The exhaust hub (gear case) will be under water and not freeze. Pouring or running antifreeze in the engine in the full tilt position will not illuminate the issue of the gear cases exhaust hub cavity freezing.