winterizing a 3.7 merc

[shawn1980]

hi everyone i'm new here wondering if i can get some help please. looking for a detailed description of the right way to winterize a 3.7 litre 1989 mercruiser. as in where the block drains are and so on. it has a raw cooling system any help is appreciated thank you.

 

[CAPTKEV85]

Re: winterizing a 3.7 merc

There is a pencil zinc on the heat exchanger in the back of it you want to remove so the sea water can drain. so it doesnt freeze and crack the exchanger. but you should flush the system with fresh water to get rid of the salt water. also make sure when you winterize that the drive is down not up. ive seen drives crack from water sitting in the lower unit. eithere then that fog the motor, fill the tank with stabil, and let hibernate.

 

[shawn1980]

Re: winterizing a 3.7 merc

i only run in fresh water so thats ok there. there isn't any place on the block i need to drain?

 

[Bondo]

Re: winterizing a 3.7 merc

a 3.7 litre 1989 mercruiser it has a raw cooling system

Ayuh,....

The 470s are Freshwater Cooled,... Aka, they have a Heat exchanger,+ run antifreeze thru the block....

Just drain the Raw waterside....Aka, the Lake water side....

 

[shawn1980]

Re: winterizing a 3.7 merc

ok thank you very much. i just had new u-joint bellows u joint's and shift bellow , gimbal installed. so i don't see a need to pull the outdrive. it's only seen maybe 10 hours since. is there anything you can put on the bellows to keep them soft and flexible?

 

[abj87]

Re: winterizing a 3.7 merc

Do you still have the owners manual? Winterizing is gone over in detail in it. The best thing for the bellows is to keep them out of sunlight and dry. If possible pull the drive off and put it somwere warm for the winter. Thats what i plan on doing in the next few weeks.