2000 Mercury Outboard 90 hp 2 stroke - Carburetor with milky paste?

JWBC

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Joined
Nov 27, 2011
Messages
14
Hi, I took my Merc outboard (2 stroke + 90 hp) on the lake this weekend and at times during the day I had a little trouble in starting the engine (I may have flooded it also in my depseration to get her started). Anyway, I took of the air box to the carburetor and saw a milky substance in the entrance to the carbs. One had a small amount of milky paste in it. Smelt heavily of fuel. I recently changed the water pump, spark plugs, lower unit oil and thermostat as part of regular maintenance and this is the first time on the water since the maintenance. Once the engine is running it runs very well and doesn't misfire or run roughly. I cleaned out the milky paste and fired it up without incident. I then ran it for another 10 - 15 mins on the lake and then re-checked and the milky substance hasn't returned. This is the first time I have seen it.

Any advice would be very much appreciated.
 

JWBC

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Nov 27, 2011
Messages
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Re: 2000 Mercury Outboard 90 hp 2 stroke - Carburetor with milky paste?

I forgot to mention in my last post that the day when this occurred on the lake there was torrential rain throughout the day which was almost horizontal due to the wind. Not sure if atmospheric conditions may have played a part.?
 

CharlieB

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Apr 10, 2007
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5,617
Re: 2000 Mercury Outboard 90 hp 2 stroke - Carburetor with milky paste?

It is normal for fuel to collect in the airbox when the motor is tilted up for transportation. The recirc system pulls most of this mixture in during operation.

Operation in such heavy rain may have allowed a small amount of water to gather in the airbox and mix with the accumulated mixture, changing its color.

Keep an eye on it, I doubt that it will return milky, but you will notice some accumulation of fuel/oil after fully tilting the motor.

Should not be anything to worry about.
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
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15,589
Re: 2000 Mercury Outboard 90 hp 2 stroke - Carburetor with milky paste?

I agee with Charlie as it was due to excess humidity......
 

JWBC

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Joined
Nov 27, 2011
Messages
14
Re: 2000 Mercury Outboard 90 hp 2 stroke - Carburetor with milky paste?

Thanks Guys...Very much appreciated.!! It had me worried.
 
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