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Oil leak ABOVE the lower unit? 90hp 1983 Johnson 2stroke (J90TLCTE)

P

paranoiccritic

Member
Hi All,

I've recently gotten a 90hp 1983 Johnson 2-stroke running. Issues were all related to fuel, and after replacing the fuel pump, all fuel lines, and rebuilding the carbs (twice - the first time I used off-brand gaskets and they deformed, the second time I used Johnson OEM gaskets and they worked like a charm). Compression is good, spark is good, motor runs like a champ now.

I had it on the water for a few hours two weeks ago, and it has been sitting on my boat in my back yard since then (for about 2 weeks). This morning, I noticed a drop of oil hanging from the trim tab, and upon inspection, there was an oil slick on the top of the lower unit all the way astern (on the top of the cavitation plate?), as well as on the sides, forward from the water intake, and there were drops of oil pooling on the bolts securing the lower unit. The oil is clear, slick, and looks like light motor oil. I am concerned that there is some leak somewhere, but this is all way above where the lower unit oil would be, right? And since it's a 2-stroke, there is no oil reservoir or separate oil system in the motor (like a 4-stroke) - what could this be, and how bad is it? Pictures available here:

https://drive.google.com/open?id=1pRi2fTpP3xTYYgMIJpR3ryGoRoUaUkJE

Please advise. Thanks in advance.

Best,

Fred
 
Do you leave the gas tank hose connected? Normal pressure buildup in the tank may be forcing a tiny bit of fuel over a long time through the carbs and engine and out the exhaust. Let's face it, they can't be expected to be absolutely 100% leak proof. Anyhoo, it is not gear oil.
 
Thanks a bunch, fdrgator - this is what I was worrying about. It is clearly coming from about the lower unit, but it didn't make sense to me b/c it's a 2-stroke and not a 4-stroke. I always disconnect the tank after I flush with clean water, but I will follow up and also try to see if there are any leaks in the fuel system that could explain this.
 
faztbullet, thanks for asking: I did reconnect the hose to the airbox drain nipple. However, I have not been replacing the gasket between the airbox and the silencer - could this be a possible culprit?
 
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