Need to winterize new Mercruiser I/O?

[Bob Drake]

I am getting close to purchasing a new deck boat, (22ft Fisher) and I was considering a Mercruiser 4.3, (190HP). I have owned outboards but never an I/0. My concern is that I will use this boat year round and do not want the risk of water freezing in the block. The boat will be gargaged,(heated) but I still venture out in cold weather. I can get this boat with a 150 HP Merc. outboard but I have been told that the I/0 will give a little better overall performance, will run with slightly less noise, and will last longer, (factory rep. However,I have been told by one dealer that I can completely drain the water out of the block during cold weather and I have also been told by another dealer that you cannot drain all the water and must add anti-freeze. I have a current brochure from Mercury Marine that advertizes that these models have an improved drain plug system that will extend the use of the boat in cold weather without risk of freezing. Does anyone out there know for sure? I will contact Mercury Marine but sometimes it difficult to know who you can believe. Would appreciate any comments.

 

[Trent]

Re: Need to winterize new Mercruiser I/O?

Bob..Just drain it and you will be fine. Alot of people add anti-freeze to help prevent corrosion in the manafolds and block. If its freshwater boat only I just drain the block, manafolds and risers. Then if you decide to use it again next week just reinstall the drain plugs and go boating. When you return remove the drain plugs again. Iv been doing this for 30 years and never busted a block.

 

[Terry G.]

Re: Need to winterize new Mercruiser I/O?

I have a 4.3 in my 2000 Bayliner. I love it! I keep it in the garage, so all I do is unscrew the 4 water plugs and trim her all the way in. If I was going to put her outside where we hit zero from time to time, I might condiser the marine antifreeeze (R/V pink stuff) in the cooling system. It would take about 5 gallons.<br /><br />tg

 

[Don Gregg]

Re: Need to winterize new Mercruiser I/O?

Hi I had a 4.3 L OMC for 11 years and live in a cold climate. I always pulled the four plugs right after getting out of the water and trimmed it all the way down to get the water out of the lower unit. I did have one problem once with the power steering heat exchanger freezing up and pushing the outer jacket apart. I just cleaned it up, resoldered it back together and ran it till I sold it this year. I know that if you are woried about this happening you can pull the hose for it off every time you get out of the water, but I think if you drive a few miles after pulling the drain plugs, that will help to get most of the water out of everywhere. Be advised! This was on a OMC 4.3L and I'm not sure what Mercury does to the engine and you should use common sence! Colorado...