Oil should'nt be coming out of there!!!!

linewetter

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Jul 21, 2009
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Hi guys, Irecently bought a 40 horse 2 stroke 2 cylinder yamaha, not really sure of the year model, no numbers anywhere that I can find, but it is a pre mix or not oil injected motor. The engine is in good condition and runs really well, but the other day I tilted the motor up to launch in shallow water and noticed gear oil coming out of the two 1/8" holes on either side the foot just above and to the rear(or toward the front of the boat) of the water intake. These holes usually have water coming out during wash out, but I know oil should not. Does this sound like a critical problem or one that can be easily repaired with a new seal. Thanks for any advice on this, and I do have a repair man that I use but cant get to him right now and this problem is killing me to know what it is. Thanks again!!
 

99yam40

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Sep 7, 2008
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Re: Oil should'nt be coming out of there!!!!

are you sure it is gear oil? smell it . gear oil has a distinct odor to it.
Also check you lower unit oil level and make sure it does not have water in the oil. If the level is OK and there is no water in gear case then what you are seeing maybe unburned 2 cycle oil and gas residue draining out.
 

Home Cookin'

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May 26, 2009
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Re: Oil should'nt be coming out of there!!!!

I would agree it's probably just unburned oil that usually goes out with the exhaust. Is it black and thin?
However, I recently had that where I hadn't seen it much before, comnig out of the prop and the two exhaust holes (on a Johnson) and withing about 3 hours use the motor died (I mean dead-it's a parts motor now) due to a failed exhaust baffle--or so I was told by a mechanic.
Since this motor is new to you, you don't have the history to know if this is unusual, you have the uneviable position of not knowing if there's something serious going on, or what to do about it. As for my situation, I don't know whether detecting it after the oil leak and before failure would have done any good, as a practical matter, on an old motor that I might rebuild.
 

linewetter

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Jul 21, 2009
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Re: Oil should'nt be coming out of there!!!!

Hi again guys, sorry I did'nt clarify my problem. The oil is gear oil and it is milky looking. There is no oil leakage at all from below these holes, as in a bad propshaft seal, I did remove the prop to check and after 3 days of sitting there is no oil from the shaft seal. I also noticed that when flushing the motor that water comes out at the back of the motor where the shift rod is visible. Never owned a yamaha so dont know where they may shoot water out, but that did look a little strange to me, especially the gear oil coming out of water holes. Thanks for any advice, I will probably get it to the tech in a couple of weeks, but I sure would like to know what to tell him to look at. Thanks again, and great forum by the way!!
 

99yam40

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Sep 7, 2008
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9,195
Re: Oil should'nt be coming out of there!!!!

like I said before, drain the lower unit, this will tell you for sure it is gear oil and will remove the water out of the lower unit, you do not want water sitting in there for long especially if it is salt water. If it is gear oil, water in the lower unit drain out first and finally the oil and water mix will come out since it is lighter than the water.
There are shaft seals under the water pump that need to be replaced from time to time along with the prop shaft seals
 
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