why is moisture forming on the outside of carbs

tashasdaddy

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50hp 73 evinrude #50373R 65 degrees atmospheric temperature moisture is forming on the outside of the carbs, like the are sweating. is this normal?
 

R.Johnson

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Re: why is moisture forming on the outside of carbs

Yes! You are looking at a refrigeration effect. They can do that any time of the year.
 

Paul Moir

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Re: why is moisture forming on the outside of carbs

That's perfectly normal. The carb actually gets colder than atmospheric temperature due to carb's venturi. The pressure drops inside it (in order to draw and atomize fuel) as air is accelerated through it. As anyone who's sprayed out a can of spray paint knows, a pressure drop in a gas causes a drop in temperature. Like a cold drink on a hot day, water from the air will condense on it.<br /><br />In extreme conditions, this can actually lead to a build up of ice on the carburetor.<br /><br />EDIT: Dang slow.. :D
 

h_lankford

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Aug 6, 2005
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Re: why is moisture forming on the outside of carbs

amazing it is not seen more often than it is.<br /><br />of course the bigger problem is when the ice is inside the carb throat, not just the outside. <br /><br />see graph for carb icing:<br /><br />
 

tashasdaddy

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Re: why is moisture forming on the outside of carbs

thanks guys, i'm still chasing the missfiring problem on the top cyl, and the immediate cut off,with no warning, just quits, i am purchasing an omc original tank, but pumping doesn't work.
 

cobra 3.0

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Re: why is moisture forming on the outside of carbs

Have you tried new plugs and cables?
 

tashasdaddy

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Re: why is moisture forming on the outside of carbs

new plugs, new coils 6months ago , spark is blue will jump from plug to block 5/8-3/4 inch, swapped coils, adj. carb according to joe reeves. baffeled. got to do compression.
 

tashasdaddy

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Re: why is moisture forming on the outside of carbs

sorry for the doudle post. bob
 
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