greenish foam from cylinder # 4 (lower) on my 100hp Merc 1992

zzzor

Recruit
Joined
Jul 3, 2008
Messages
3
I went to tune up my motor listed above. when I removed the lower plug I found it had a type of laquor looking coating on it. I could not see the top of the piston well so I turned it over to top the piston. When I did that a large quanity of greenish looking water oil combo came out. The other cylinders seem to be normal.

Any thoughts on what would cause this and perhaps a solution?

Thanks
 

o/b tech

Petty Officer 2nd Class
Joined
Apr 15, 2005
Messages
198
Re: greenish foam from cylinder # 4 (lower) on my 100hp Merc 1992

Possible blown exhaust gasket on the powerhead allowing water to enter the cylinder or the motor has ingested water when you backed out of the throttle. More than likely a bad gasket. Hopefully the motor has not been sitting for any length of time. Try to spray some fogging oil into the cylinder so it can protect the cylinder and the crank.
 

zzzor

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Re: greenish foam from cylinder # 4 (lower) on my 100hp Merc 1992

And fogging oil is?

I was the first time I used it from last fall, I did run the fuel out with a hose adapter before I stored it.
 

Kev144

Petty Officer 2nd Class
Joined
Oct 16, 2007
Messages
159
Re: greenish foam from cylinder # 4 (lower) on my 100hp Merc 1992

You should be fogging the motor in every fall with fogging oil. It will prevent rust etc in your crank and motor. Failure to do so will cause problems down the road. Eventually require a total rebuild. You can buy it at any marine dealer. Just pull the spark plug and spray inside. When you winterize i usually spray it into the carbs for a bit until it dies, drain the gas in the carbs and spray some down the motor.
 

zzzor

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Jul 3, 2008
Messages
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Re: greenish foam from cylinder # 4 (lower) on my 100hp Merc 1992

Thanks.

I left as an FT 2nd class in 81, USS Downes FF 1070 32nd st.

You still active?
 
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