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9.9 Mariner Seeping Oily Residue Out Exhaust

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capnbo

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Test ran the 9.9 Mariner for 10 minutes in gear in a tank to check out the water pump kit function I installed last night. Good flow out of weep hole but had a brown oily residue seeping out of the exhaust. Is this normal or do I need to be concerned before using? Thanks. Tried to attach pictures but could not.
 
Quite normal, I have a 2000 9.9 Merc purchased new and its had a runny nose since it was new. Idle mixture and timing are correct and accurately mixed oil and gas. some have suggested that the seal oring for the check ball in the primer chamber may be leaking and causing a rich condition may be the culprit.
 
To attach pictures, they have to be reduced to anything smaller than 1000k.
Funny, but that is not normal for MY 2 stroke outboards. Wonder why?
 
Thanks for the replies. Going fishing! The motor sat for -+10 years without being used. I replaced the water pump, changed gear oil, and spark plugs. Bulb pumps the bowl full and stays hard. It takes10-15 pulls to get it to fire, then several more to get it running. It will start on one pull throughout the day after that. Any ideas to get it started quicker when cold? Maybe carburetor needs cleaning?
 
What year is it? Could be your starting procedure needs "adjustment"....or....
If it has a pump like pictured here, it could be damaged from fuel containing the "E" word. What do you think? It sat and ethanol damaged the diaphragm? Just a WILD GUESS!
 

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It is a 1994. Serial # OGO57543. What year motor is the thumbnail from? I always ran it out of gas until it stopped. There was no fuel in the cup when I started up the first time after lay up.
 
Not sure what year this screenshot is from. Mercury/Mariner is not always fun to date or interchange. Running out fuel still leaves enough behind to eat diaphragm material if ethanol is present at 10 percent. Does it have that primer/choke combination? Then it will appear like this. I have to replace these pumps quite often. Always keep a couple in stock here. Ethanol is mandated in MN. Many boat owners don't heed shade tree mechanics advice. Dealers don't care, they need the work.
 
Yes, it has the pull out primer/idle adjustment knob. How much does a new fuel pump cost? I agree this is probably the issue. Thanks.
 
timguy said:
To attach pictures, they have to be reduced to anything smaller than 1000k.
Funny, but that is not normal for MY 2 stroke outboards. Wonder why?
Click to expand...
SOOOOO you have 100% combustion on a 2 strk outboard? That is absolutely amazing How did Evinrude not snatch you up??
 
Ha! I never went to real school.....only the school of "hard knocks", and never graduated from it either. It's certainly no secret.....the most complete combustion is achieved with the minimal amount of lubricating oil in the mix. It's probably not 100 percent, but the objective is to keep 2 strokes around a long long time yet. New engineering is of no interest to me so in order to hang on....awhile....I have to walk "on the fringe". Sure, some may say I take my chances at between 64 and 100:1, but my motors keep running, running, and running.
 
Trouble shooting the starting issue, I found on the primer/injector top piece that the primer arm was not depressing the blue button to prime/send fuel to the carburetor from the bowl. Adjusted the arm and manually worked the button that was stiff to loosen it up. Starts first pull now.:)
 
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