Black oil leaking from behind prop?

tkdunn

Seaman
Joined
Jul 4, 2011
Messages
68
1996 Evinrude 112 SPL. I winterized my motor last month. I replaced the gear oil at that time. It was my first time winterizing a motor - could this black oil be from using too much fogging oil? :facepalm: I've read on other websites that it is most likely from unburned 2 stroke oil in the exhaust. It didn't have a strong odor and washed off easily. I took some pictures for clarification. I knew that I could rely on iboats for a right answer. Thanks :)

oil 1.jpgoil 2.jpgoil 3.jpgoil 4.jpg
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: Black oil leaking from behind prop?

looks very normal , i wouldnt worry about it.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Black oil leaking from behind prop?

Unburned gas and oil. Not to worry.
 

5150abf

Vice Admiral
Joined
Aug 12, 2007
Messages
5,808
Re: Black oil leaking from behind prop?

I will 3rd that, no worries.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,075
Re: Black oil leaking from behind prop?

Nope a total rebuild is in order!!
!Kidding,just unburned oil and gas.
I use the purple cleaner from AutoZone.I spray it under the hood and let it set.Then hose it out.
Then spray with a good silicone spray.Wd-40 is OK.J
 

halfmoa

Ensign
Joined
Aug 19, 2011
Messages
955
Re: Black oil leaking from behind prop?

Nope a total rebuild is in order!!
!Kidding,just unburned oil and gas.
I use the purple cleaner from AutoZone.I spray it under the hood and let it set.Then hose it out.
Then spray with a good silicone spray.Wd-40 is OK.J

Most of those purple cleaners are sodium hydroxide based. Sodium hydroxide combined with water eats aluminum for breakfast and leaves hydrogen and anhydrous sodium aluminate in it's wake. Be careful!


2 Al + 2 NaOH + 2 H2O = 2 NaAlO2 + 3 H2
 

daselbee

Commander
Joined
Jan 20, 2009
Messages
2,765
Re: Black oil leaking from behind prop?

I have to disagree.

It is unburned two stroke oil and fuel, but I consider it to be a sign that there is incomplete combustion somewhere.
Personally, I would investigate the ignition system, look for hot spark, look for the possibility of a dropped cylinder, look for an extra rich cylinder, etc. New plugs will help immensly with that task. Examine them after running.

If you rule all that out, then live with it.

The only engine I ever had that did that was dropping a cylinder, that's why I look for a problem first before letting it go.
 

daselbee

Commander
Joined
Jan 20, 2009
Messages
2,765
Re: Black oil leaking from behind prop?

2 Al + 2 NaOH + 2 H2O = 2 NaAlO2 + 3 H2

Halfmoa.....you ever see a TV series called "Breaking Bad"?

If not, look into it. You might just get a kick out of it.
 

halfmoa

Ensign
Joined
Aug 19, 2011
Messages
955
Re: Black oil leaking from behind prop?

Halfmoa.....you ever see a TV series called "Breaking Bad"?

If not, look into it. You might just get a kick out of it.

LOL yeah. The sick part is chemistry is just a hobby.

Quantum physics on the other hand is an obsession.
 

tkdunn

Seaman
Joined
Jul 4, 2011
Messages
68
Re: Black oil leaking from behind prop?

Thanks for confirming. This has never happened prior to winterization. Maybe I didn't do something quite right, I don't really know. lol It's all a learning experience to me. Daselbee the plugs were replaced in July of 2011. The engine was serviced and a power pack replaced probably around August. Even compression all around. Ran fine ever since.
 

nwcove

Admiral
Joined
May 16, 2011
Messages
6,293
Re: Black oil leaking from behind prop?

LOL yeah. The sick part is chemistry is just a hobby.

Quantum physics on the other hand is an obsession.

halfmoa.....which character on the " big bang theory" are you? lol
 
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