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Nissan 8hp leaking lower unit oil

R

rollertoaster

New member
My god father gave me a Nissan 8 hp NS8B, which in all honesty has seen better days. All lower unit seals have been replaced, however the motor is leaking lower unit oil out of a hole in the front side of the lower unit when the motor is laying down. When its standing upright it doesn't leak, and when pumping in new oil, it doesn't leak out of the hole. When its in the water, and idling,water comes out of this hole. I'm honestly not sure whats happening, has anyone else had this problem?

Here is a picture of the hole in question. I have a video too which I can upload.

http://i.imgur.com/TXPeFhK.jpg?1
 
That's a drain hole, and water will come out of it while running.

If the fluid is black and stinky, it is unburned fuel/oil mix running down the exhaust passage. If so, it's normal.

If it is the color of new LU lube (with that characteristic aroma), you may have a shift bushing o-ring or drive shaft seal leak. Does it get water mixed in with the LU lube (milky when changed)? If so, the LU is leaking. Many lazy mechanics don't do the shifter o-rings, because they require patience and dexterity to change.
 
pvanv said:
That's a drain hole, and water will come out of it while running.

If the fluid is black and stinky, it is unburned fuel/oil mix running down the exhaust passage. If so, it's normal.

If it is the color of new LU lube (with that characteristic aroma), you may have a shift bushing o-ring or drive shaft seal leak. Does it get water mixed in with the LU lube (milky when changed)? If so, the LU is leaking. Many lazy mechanics don't do the shifter o-rings, because they require patience and dexterity to change.
Click to expand...

Thanks! I was worried the hole wasn't supposed to be there. I think you're right, and it actually might be unburnt gas/oil since it has a black tinge to it. I'll be running the motor on friday for its first time on the boat. I plan on draining the LU oil on saturday to see whether or not water is getting in there.
 
2 possibilities: Either there was residual water in the LU after the "seals were changed", or, more likely, you still have a leak.
Who replaced the seals? Did they also do the cam rod o-rings?
At this point, you can either pressure test the LU with air (look for bubbles underwater), or Properly re-install a complete new seal kit.
 
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