winterizing 4cyl merc 120 HP (1974) closed system

[ruggles]

Do I need to drain the manifold and block on a closed system or just fill with antifreeze and drain the heat exchanger? The leg is down already.

Thanks

Ryan

 

[Bondo]

Re: winterizing 4cyl merc 120 HP (1974) closed system

4cyl merc 120 HP (1974) closed system

Ayuh,... Ya sure that 2 ain't a 7,..??
I've never seen a closed cooling 2.5l....

Without seeing what you've got,... It's Impossible to tell How it's plumbed...

 

[ErieRon]

Re: winterizing 4cyl merc 120 HP (1974) closed system

Do you have the manual ?

#1 or #2...check against your serial number.

 

[ruggles]

Re: winterizing 4cyl merc 120 HP (1974) closed system

yes it's a 120 Merc 2.5l with a closed system. I'll check the serial #. When opened up the block drain coolant came out so I am thinking keep it closed?

 

[ruggles]

Re: winterizing 4cyl merc 120 HP (1974) closed system

Do you have the manual ?

#1 or #2...check against your serial number.

**** by that pic I should have opened up the manifold drain plug. The manifold needs replacing but still I should open that one up tonight

 

[Bondo]

Re: winterizing 4cyl merc 120 HP (1974) closed system

Ayuh,... According to Ron's picture,..
The block is antifreeze,+ the manifold is Raw water...

Is the antifreeze Strong enough,..??

 

[ruggles]

Re: winterizing 4cyl merc 120 HP (1974) closed system

yeah it's strong enough. I live in Vancouver, Canada and it only gets to -15 C
here at the lowest.

Cheers

 

[ErieRon]

Re: winterizing 4cyl merc 120 HP (1974) closed system

-15 C...isn't that like 5 F That's cold enough...


BTW; Vancouver looks great. I want to go there sometime.

Look at the manual. There are pet-cocks for the seawater section & the coolant section. I have an '84 470 and all I do is drain the seawater section, check the coolant concentration, loosen the end caps on the heat exchanger, and I'm done.

Read the manual...you may have a manifold plug...and see below.

 

[ruggles]

Re: winterizing 4cyl merc 120 HP (1974) closed system

Vancouver is great. I actually live on the Sunshine Coast which is a 40min ferry ride from West Vancouver. It's very picturesque. There is def a manifold plug. thanks for the help

 

[ErieRon]

Re: winterizing 4cyl merc 120 HP (1974) closed system

No problem. I'm looking forward to getting there some day.

 

[Don S]

Re: winterizing 4cyl merc 120 HP (1974) closed system

Vancouver is great. I actually live on the Sunshine Coast which is a 40min ferry ride from West Vancouver. It's very picturesque.

It's very picturesque Is a bit of an understatement. The LOML and I spent 3 months one summer, exploring the Gulf Islands, Sunshine Coast, and Desolation Sound, aboard our 41' Islander Freeport Ketch that we lived aboard for 12 years. Some wonderful memories of that trip. Then we went to Alaska for a trip up the inside passage .......... that trip took 14 years before we came back to Washington.

 

[Glastron_V210]

Re: winterizing 4cyl merc 120 HP (1974) closed system

Hey there fellow BCer. I live over the straight in Duncan.

It's very good to get familiar with your cooling system, so you've already won.

Last night was COLD by my standards!

Anyway, what I did to be sure was crack the drains on the block and manifolds. Green is good. Anything that is not green, drain it!

I found out that I have closed block and manifolds this way. The book says I don't have any of it (Factory anyway) so I'ts not always the best source, unless you can physically see its identical.

I doubt you have power steering, but if you do there is a power steering fluid cooler on the raw water intake side of the heat exchanger which can have water in it and bust up...ask me how I know!

If not, I think it's still a good idea to detach and drain the tube on the raw water side of the heat exchanger and open up the riser(s) (Where the raw water goes out) drain plugs to make sure there's no water there.


Happy holidays!

Chay

 

[Glastron_V210]

Re: winterizing 4cyl merc 120 HP (1974) closed system

BTW, Vancouver, the island, Sunshine Coast, Gulfs, San Yuans and Desolation, Princess Louisa, Octopus Islands, Broughtons, etc are all way overrated! You don't want to come here. Trust me.

Gotta go now,

Chay