Johnson lower unit oit leak??????

marshall1197

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Apr 8, 2009
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5
Hey all, I have a 1975 9.9 Johnson ss.
I fired it up the other day, and noticed a greyish oily film coming out from around the prop, I drained the gear oil all was good, no discoloration, I replaced the big o-ring on the bearing house assembly, figured I would start with the easy one. I removed the lower unit to inspect the water pump, everything is good up there, I noticed in the open cavity alot of this greyish oily residue. I cleaned it out best I could, so I would not get a false impression that is is still leaking when I ran it again, but it is still leaking, it does not start right away, it took about a minute to show again, I am thinking I will just rebuild the whole lower unit, but really do not want to right now. any help would be greatly appreciated, Thank you to all .
 

Rick.

Captain
Joined
Jul 30, 2006
Messages
3,740
Re: Johnson lower unit oit leak??????

Stop!!!!! That is just unburned oil from the exhaust and prfectly normal and expected. Your motor is fine. Rick.
 

marshall1197

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Apr 8, 2009
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Re: Johnson lower unit oit leak??????

really? it is kinda thick, but as you say that I have been wanting to put fresh fuel in the tank. The guy who had it befor me must have put way too much oil in the mix, from the smoke coming out of the exhaust, and looking and smelling in the tank, I will try new fuel tomorrow.....one added question under the motor cover dead center on the back is a hole, is this where the water is supposed to come out, or does it come out the exhaust from the prop, occasionally water "spits" out from there, not a steady stream. I will say I put a new impeller in today.
 

BassSpotter

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Mar 18, 2009
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10
Re: Johnson lower unit oit leak??????

I'm with Rick on this one. I had a similar experience on an older motor of mine.
 

Drewdaddy

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Apr 7, 2009
Messages
25
Re: Johnson lower unit oit leak??????

Mine does the same thing. I was worried at first but after some research it does seem that it is perfectly normal. Actually for it to be greyish is a good thing, it supposedly means you have a lack of carbon build up and that is just unburnt oil as previously stated. It can also be somewhat black in color as well.
 

Mas

Lieutenant Commander
Joined
Oct 3, 2006
Messages
1,656
Re: Johnson lower unit oit leak??????

Yes, save your money and just monitor the LU lube. Some oily sludge is expected in two strokes.

If you're worried about the LU, just pull the lower plug and check for water/discoloration. If OK replace plug with a new washer.

MAS
 

marshall1197

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Apr 8, 2009
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Re: Johnson lower unit oit leak??????

wow I have had 2 other outboards a 1957 5.5 seahorse, and a 1970 something evinrude, and did not see this, I will monitor the lu oil, and put fresh fuel tomorrow, like I said I think he over did it with the fuel/oil ratio, but I was worried because it was thicker consistency.....what about my added question as far as the water discharge?
 

Robj

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Mar 22, 2007
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1,441
Re: Johnson lower unit oit leak??????

As already stated unburnt oil leaking from the exhaust port on the leg is common with 2 strokes. The way I can tell the difference is by the smell. Gear oil has a distinct sulfur smell, while burnt 2 stroke oil does not. If you are worried, run it for a few hours, and then change/check the gear oil. If it is couldy, then you have a problem, if it is not then you are OK.

Have a great day

Rob.
 

Rick.

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Joined
Jul 30, 2006
Messages
3,740
Re: Johnson lower unit oit leak??????

A good decarb. will help get rid of some accumulation (as well as carbon which is the main reason for doing it). If you've been barrel running it it seams to me to be worse which I think is because you never open it up and expel the accumulated oil. Recently I learned that 100% (or close to it) of the oil in a two stroke mix goes through the leg and into the water. As it cools in the leg it sticks to the surfaces and runs very slowly down the leg and out the prop or sometimes the little water drain ports as well. At the end of a days trolling I always take my motor for a full out run which seams to clean some of the gunk out as well as clean up the plugs. I have a small area at my work where I store my current project motor and I'm amused how many times guys have pointed out the grey stuff as a significant problem. It isn't. Fresh gas is always a good thing but I doubt it will make much of a difference as far as the grey stuff is concerned. It seams to me on a 75 that is the location of the pee hole. You should have a steady stream always. You may detect an almost strobe like stream at very low idle and as the rpm's increase so will the stream pressure to a point. You say you replaced the impeller today and I'm glad to hear that given the pee stream you speak of. You might try to push a weed eater string up the hole to see if that improves the flow but if it doesn't you must find the problem or risk an overheat situation. Here is a link which is a "must read" for all us 9.9 and 15 OMC owners. A great deal of information, but a fantastic insight and explanation of their performance issues. Rick.
http://www.sschapterpsa.com/ramblings/OMC/OMC info.htm
 

Robj

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Mar 22, 2007
Messages
1,441
Re: Johnson lower unit oit leak??????

Hello,

Rick that is a great link.

Thanx and have a great day,

Rob.
 

marshall1197

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Joined
Apr 8, 2009
Messages
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Re: Johnson lower unit oit leak??????

yes it was very, very, very helpful, it is saved in my favorites for future reference, and thank you to all who replied I slept a lot better last night, seriously. I was really concerned, also that link stated that water does not come out of the hole right below the motor cover center on the back side, that it comes out through the prop, but a water discharge can be added to come out from the top side, the motor does not seem to run hot to the touch, and the paint on the motor is factory new, so I think I will avoid the hassle of adding it. again thank you for the help, and I now know where to come for better answers.
 

marshall1197

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Apr 8, 2009
Messages
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Re: Johnson lower unit oit leak??????

wait a minute, I wrote that last part wong, i think I made it sound like I will go to that link for better answers, I really meant that I will come here, to you guys for better answers, you all were very quick to respond
 
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