Black oil? Where is it coming from?

R

Ryster77

Cadet
Joined
Oct 24, 2006
Messages
7
1977 Johnson Javilen 85 hp. Got it out for the first time and hooked up ears with hose and started it. I let it run for about 2-3 minutes and then shut it off. The next morning I found black oil under motor...leaked out exhaust? Ran down onto floor about 6 inch diameter oil spot. The person who I bought the boat from said the gas was 50:01 or richer a year or two old. It looks like it came out from behind prop. Any ideas?

Thank you
 
Joe Reeves

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Black oil? Where is it coming from?

The mixture is indeed 50/1.... 1pt of 50/1 TCW-III oil to 6gal gas.A fuel rating of 87 will be fine.

Loosen the large slotted screw at the bottom of the gearcase to check the coloring of the gearlube. If it's black, you may very well have a lower unit leak.

If however, the gearlube is a normal coloring, that bl;ack substance would be the excess unbuirnt gas/oil mixture draining down thru the soot lined exhaust housing (it happens).
 
Creole

Creole

Recruit
Joined
Jul 15, 2006
Messages
4
Re: Black oil? Where is it coming from?

I had this same problem on my 79 100hp turns out it was the carbs. Believe it or not the carbs actually allowed the gas to leak right through and what it was doing is the gas was cleaning all the junk from the exhaust and leaking it right out. Run it again and the put a bucket under it to collect fluid just to make sure.
 
C

casi77

Petty Officer 2nd Class
Joined
Mar 13, 2006
Messages
122
Re: Black oil? Where is it coming from?

nothing to worry about, as Creole described its most likely the unburnt gas made through the exhaust and washed with the carbon on the exhaust.
 
E

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Black oil? Where is it coming from?

To Creole: If the gas and oil mix is running through the carburetors when the motor is off, then the float valves are not working and it is time for a carburetor rebuild. That is not only a mechanical problem, but a very dangerous condition.
 
B

baja power

Petty Officer 2nd Class
Joined
Apr 7, 2004
Messages
116
Re: Black oil? Where is it coming from?

I had the same problem on my '95 2 stroke 15 hp.

Got it out of storage this spring... fired it up and noticed oil blotches coming from the hub area.. After letting it sit there was a pool of black oil under it where it had dripped down the skeg. I will be taking it out this weekend for a first run of the year. I?m just going to run it and see what happens. Not too worried about it. :)
 
You must log in or register to reply here.
Top