Black residue

[romanspapa1]

I have a 1996 Force 75 HP 2 stroke by Mercury. After running it and it set on my driveway a couple of days I see a black oily substance on the driveway that came out of the lower unit where water and exhaust exit around prop. I checked my lower unit fluid which is full but is a greyish color. I did not see any water when i pulled lower plug on unit. Would water in the oil make this greyish color or is that normal for gear oil? If this is not the culprit then what is causing the oilly black stuff on the driveway? Thanks for any input or suggestions.

 

[Bob_VT]

Re: Black residue

Black oily around the exhaust is unburned (slightly charred) 2 stroke oil and very normal.

Grayish oil in the lower unit is not good. It means water has mixed in and it is time to flush the unit and change the gear oil....... then keep an eye on it. If it happens again you may have a bad seal ........ make sure both the fill and top plugs are tight with washers.

 

[catfishcarl99]

Re: Black residue

Black oily around the exhaust is unburned (slightly charred) 2 stroke oil and very normal.

Grayish oil in the lower unit is not good. It means water has mixed in and it is time to flush the unit and change the gear oil....... then keep an eye on it. If it happens again you may have a bad seal ........ make sure both the fill and top plugs are tight with washers.

what he said /\ /\ /\ /\ /\ /\ /\

 

[romanspapa1]

Re: Black residue

Thanks guys for the info. I just ordered new blue washers forthe plugs. What gear oil do you like best?

 

[romanspapa1]

Re: Black residue

Does anyone know why there is unburned 2 cycle oil in this motor? I never had this problem with any other motor. I mix 50:1 16oz to 6 gallons.

 

[emoney]

Re: Black residue

Probably the reason you're seeing it now is where the exhaust exits. Pretty sure that every make will have a little unburned fuel it's just a flaw of the combustible engine, not specific to Force.