Where do I start ? Grey sludge from cowling area

[Moody Blue]

Last couple times out with this motor (1992 9.9 Evinrude)noticed a thick grey/white sludge running down the outside of the midsection from somewhere under the cowling. Also evidence of the same gunk from the exhaust relief port and on the inside of the prop hub (thru hub exhaust). While idling, the motor also coughs once in awhile and spits a bunch of this stuff out into the water then stalls. Starts OK and then runs good for awhile again. Compression check shows 115PSI on top cyl and 125 on lower cyl. Plugs are black and a little on the oily side. Am in the process of general maintenance and adding an electric start to the motor. Now would be a good time to fix anything else that might be wrong. Any thoughts?

 

[Rudy Brown]

Re: Where do I start ? Grey sludge from cowling area

Sounds like the stuff that came out of my motor after de-carbing it. A thick grey sludge type stuff. I've been told that sta-bil will remove carbon. Is your fuel treated with sta-bil?

 

[mikeyzx2]

Re: Where do I start ? Grey sludge from cowling area

The sludge is coming from the fuel/oil mix. The sludge coming out from under the hood, does it look like it's originating from where the powerhead meets the midsection? That would be a gasket leak if so. Black and oily plugs are fouling, change them and see if that helps. Compression looks good, nothing to worry about there. If the plugs keep fouling like that you may need to look into the ignition.

 

[Moody Blue]

Re: Where do I start ? Grey sludge from cowling area

I have not noticed this before and have run this motor since new, 14+ years. Just started towards the end of last season. I also suspect a gasket failure but is that the cause of this or just a symptom? Is something else wrong I should be looking into?

 

[w2much]

Re: Where do I start ? Grey sludge from cowling area

Just a guess from a novice. I have a 6 HP Evinrude which has the same symptoms. I found it to be the set of seals, springs and gaskets which are situated on the top of the drive shaft. They prevent crankcase oils from leaking from the lower crankcase. Check a diagram on Ishopmarine.com for your engine. Can't say yours is similar but the symptoms certainly are. Good Luck...

 

[Moody Blue]

Re: Where do I start ? Grey sludge from cowling area

Thnaks for that w2much. Are these seals installed in the powerhead itself? What do you mean by "top of the driveshaft"?

 

[MCM]

Re: Where do I start ? Grey sludge from cowling area

RodC, I think you'll find this link very helpfull & informative, it is written and maintained by one of our members "The machinist"<br /><br /> http://www.wisnersinc.com/Fishing Info/Johnson 9.9_15.htm

 

[Moody Blue]

Re: Where do I start ? Grey sludge from cowling area

A great looking site, thanks. Something to read this weekend for sure.

 

[G DANE]

Re: Where do I start ? Grey sludge from cowling area

First I would check if the carb is leaking of float needle valve is stuck, makin carb flooding.