Outboard flushing

[marchhare]

I think my 2.5 Mariner has got some salt crystals or such reducing the water flow. I have checked out the impelor and all seems ok. Have cleaned the tell tale tube into the cylinder head water jacket and the tell tale flow has improved which makes me think there is some gunge in the water jacket. Has anyone got any knowledge of a product(s) that could be used to flush the system to disolve the salts and crud that may be lurking in the system?

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[Joe_Cole]

I don't think that there's anything that will readily do it for you. I stripped my engine (the same as yours) a while ago and found that it was easier to do this job than I had expected. It took a couple of hours and the cooling is now working properly.

Joe

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[cliff]

Lime scale remover or the stuff one uses to descale furred up kettles etc. Be sure to flush the engine well with fresh water after degunging.

I use a very small running tank just big enough to slip over the leg (removing the prop first) only need about 1 ½ galons of water to cover the water inlet and the widdle hole discharge neatly runs back into the tank so no loss of coolant / descaler.

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[Trevor_swfyc]

Joe,
I confir its no good using acids as it is easy to remove the head, after removing the plastic under cover. The cooling chamber in mine was solid with deposits and I always flushed it after use. The deposits were so solid it was a job to tell alloy from deposit material, it took an old screwdriver to chip it out. I also drilled out the tell tale outlet while the head was off using the next size drill in 0.5 mm up from the one that fitted. I also reused the head gasket so far with no problems.

Trevor



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[Joe_Cole]

Exactly what I found! I was amazed at how much crud there was in the water jacket, it makes a mockery of all that careful flushing out of the engine after use.

Good idea to enlarge the tell tale outlet; I'll try that next time.

Joe

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[nickjaxe]

Hi you guys that flush your engine after every outing and still found blocked passages, have you owned them from new and flushed every time you used them, or did you buy them 2nd hand.

Nick.

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[Trevor_swfyc]

I purchased mine from new and only use it on the 2 weeks summer cruise. So when I say I flushed it after use to be fair that was when I returned from holiday. The problem is the salt water that lays in the head boils off and the salt deposits build up before I get to flush it. Nobody rushes up the ramp with the outboard to immediatly flush it with fresh water do they! as I think this is what you would have to do to stand any chance of avoiding an eventual total blockage.

Trevor



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[nickjaxe]

Mmmmm thats worrying I do mine every outing had it from new like you.

Nick.

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[Joe_Cole]

I also had mine from brand new.

Joe

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