Removal of scale build up in cylinder water jacket

[Monte NZ]

Any suggestions please on how to clean out the lime type build up in the cylinder water jacket on my 1991 2.3hp Evinrude which I am restoring?
I have wondered if there is any solution that can be run through the motor that will dissolve it without causing corrosion.

Thanks in advance Monte NZ

[fleetwin]

Sorry, I don’t know of any solution that can be run through the engine safely. I guess the only thing that might help is to run the engine in the water long enough to warm it up good, then pull the head off…Perhaps that build up will soften a bit. Do you have the head off now? If not, how do you know the block is full of salt build up?

[Bob Wight]

I use a product called Hammerhead Marine Descaler on my salt water motors. Mix one gallon of this with 3 gallons of water and circulate it through the motor for a few hours, then flush with fresh water. Works real well and is safe to use on aluminum.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1957 Evinrude 3022
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[crosbyman]

tried warm/hot vinigar ?? works great in my coffee machine for calcium deposits salt ???

Joining AOMCI has priviledges 🙂

[Monte NZ]

Thanks Fleetwin,Bob and Crosbyman for your replies.

In reply,I haven’t had the head off, but going on what I have found in the water passages when I took the actual power head off the trunk and what was in the cooling pipe
I suspect that the water jacket round the cylinder will be pretty caked up too.

We are in lock down again with this darn Carona virus so I’m unable to get parts at present, so was thinking of other methods to clean out the system.
The more I think about it, removal of the head could be the way to go and just be patient until I can get a new head gasket.

Thanks once again.
Monte NZ

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