1989 150hp Yamaha Leaking oil....

Asainz320

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Sep 27, 2006
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137
When taking my boat out yesterday, i noticed that there was oil all over the floor, right under the engine. It was coming out of the exhaust and from the prop. I didnt pay much attention to it since i had spill some oil from the main tank a few days before so i thought it was the same oil which had driped down.

So i took it to the water and when i turned the key i got a buzzer sound. I lift the cowling and sure enough it was out of oil in the main tank! I was concerned cus i didn't see any oil inside the cowling everything inside there was really clean.

I let the pump run for a couple of minutes to fill up the tank. When i turn on the engine it started smoking a lot. This made me realize that the oil had leaked inside the eninge and thats why it was dripping out of the exhaust when parked at my house.

What can this be and how can it be solved?
Thanks.
 

rodbolt

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Sep 1, 2003
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20,066
Re: 1989 150hp Yamaha Leaking oil....

if its the original pump it will have 6 nipples facing up. they had the oil check valves in the pump. usually when a valve fails it will drain the engine oil tank into a cylinder. if the cylinder has an intake or exhaust port open it will continue draining either out the exhaust or into the crankcase or both.
there is a fix.
purchase a pump kit.
yours has most likly been damaged by debris, usually from improper oil system filter maint.
I have seen it bad enough to actually hydro lock an engine.
 

Asainz320

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Re: 1989 150hp Yamaha Leaking oil....

Hey thanks a lot for the quick reply rodbolt!

Can it be cleaned out or is it completly necesary to buy the new kit?
 

rodbolt

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Re: 1989 150hp Yamaha Leaking oil....

dunno.
the consequences of oil pump failure compared with the simple easy replacement of the pump isnt worth it so I never tried.
 

Asainz320

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Re: 1989 150hp Yamaha Leaking oil....

in your opinion, is it better just to take the mixing mechanism off and mix manually? or just leave it and replace the pump?
 

rodbolt

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Re: 1989 150hp Yamaha Leaking oil....

me? I would simply replace the pump. however carefully read and heed all instructions. I would also run the first 6 gallons or so with premix to insure the new pump is operating correctly.
Yamaha uses a very simple setup but it does require periodic maint and that requires some knowledge of whats going on and why.
 

Asainz320

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Re: 1989 150hp Yamaha Leaking oil....

Alright, thanks a lot for your help, i really apreciate it!
 

sc_shane

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Mar 1, 2007
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Re: 1989 150hp Yamaha Leaking oil....

...
there is a fix.
purchase a pump kit.
yours has most likly been damaged by debris, usually from improper oil system filter maint.
I have seen it bad enough to actually hydro lock an engine.

I think I might be experiencing the same problem, rodbolt. So when you say buy a pump kit, you're saying buy the entire assembly? For instance, for my 1989 90HP it would be 6H1-13200-02-00? Or are you saying there is a rebuild kit for it? Really appreciate the help. I'd hate to not spend $100 and have a major problem on my hands. Thanks a bunch.
 

rodbolt

Supreme Mariner
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20,066
Re: 1989 150hp Yamaha Leaking oil....

no rebuild kit.
if your experiencing a problem start a new thread.
keeps confusion down :)
 
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